ArticleLiterature Review

Social scale and structural complexity in human languages

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  • Ecole Normale Supérieure de Paris-PSL
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Abstract

The complexity of different components of the grammars of human languages can be quantified. For example, languages vary greatly in the size of their phonological inventories, and in the degree to which they make use of inflectional morphology. Recent studies have shown that there are relationships between these types of grammatical complexity and the number of speakers a language has. Languages spoken by large populations have been found to have larger phonological inventories, but simpler morphology, than languages spoken by small populations. The results require further investigation, and, most importantly, the mechanism whereby the social context of learning and use affects the grammatical evolution of a language needs elucidation.

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... Previous work has largely focused on technological case studies, while larger populations appear to have the opposite effect on linguistic complexity. Languages with a greater number of speakers have more diverse vocabularies, but simpler grammatical structures (Bromham et al. 2015;Lupyan and Dale 2010;Nettle 2012;Reali et al. 2018), and artificial language experiments have shown that larger groups produce simpler communication systems that are easier for subsequent generations to learn and reproduce (Fay and Ellison 2013). Similarly, in the case of folk tales, population size correlates positively with diversity in tale type but negatively with diversity in narrative motifs (Acerbi et al. 2017). ...
... The positive correlation we identify between tune popularity and diversity is consistent with the hypothesis that tunes played by larger communities of musicians have more frequent opportunities to diversify due to innovation or copying errors. Therefore, larger effective cultural population sizes support more diverse cultural repertoires in folk music as they do in other domains including technology and language (Acerbi et al. 2017;Bromham et al. 2015;Collard et al. 2013;Henrich 2004;Kline and Boyd 2010;Kobayashi and Aoki 2012;Lupyan and Dale 2010;Nettle 2012;Powell et al. 2009;Reali et al. 2018;Shennan 2001). Together with our simulations which consistently showed that larger populations increase tune diversity as a result of more frequent innovation, these results suggest that the positive relationship between population size and innovation rate generalises across diverse contexts. ...
... Together with our simulations which consistently showed that larger populations increase tune diversity as a result of more frequent innovation, these results suggest that the positive relationship between population size and innovation rate generalises across diverse contexts. The inverse-U shaped relationships that we generally identify between popularity and melodic complexity, however, differ from both the positive and negative relationships previously identified in studies of technology and language respectively (Acerbi et al. 2017;Bromham et al. 2015;Collard et al. 2013;Kline and Boyd 2010;Lupyan and Dale 2010;Nettle 2012;Reali et al. 2018). The reductions in relative diversity and evenness that we find in popular tunes suggest that larger populations facilitate stronger convergence upon favoured tune variants, in this case those with intermediate levels of complexity. ...
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Article
Demography, particularly population size, plays a key role in cultural complexity. However, the relationship between population size and complexity appears to vary across domains: while studies of technology typically find a positive correlation, the opposite is true for language, and the role of population size in complexity in the arts remains to be established. Here, we investigate the relationship between population size and complexity in music using Irish folk session tunes as a case study. Using analyses of a large online folk tune dataset, we show that popular tunes played by larger communities of musicians have diversified into a greater number of different versions which encompass more variation in melodic complexity compared with less popular tunes. However, popular tunes also tend to be intermediate in melodic complexity and variation in complexity for popular tunes is lower than expected given the increased number of tune versions. We also find that user preferences for individual tune versions are more skewed in popular tunes. Taken together, these results suggest that while larger populations create more frequent opportunities for musical innovation, they encourage convergence upon intermediate levels of melodic complexity due to a widespread inverse U-shaped relationship between complexity and aesthetic preference. We explore the assumptions underlying our empirical analyses further using simple simulations of tune diffusion through populations of different sizes, finding that a combination of biased copying and structured populations appears most consistent with our results. Our study demonstrates a unique relationship between population size and cultural complexity in the arts, confirming that the relationship between population size and cultural complexity is domain-dependent, rather than universal.
... While necessary, correlational studies of this kind are not sufficient [28][29][30]. Other types of evidence are required to support the existing hypotheses, to demonstrate and explain the presence of causality [2,31], as well as to safeguard against type I errors in large-scale typological analyses (see detailed discussion in [32]). ...
... The iterated learning model [49,50] has been mentioned as a particularly promising approach for the investigation of the actual mechanisms of simplification and complexification [28,51]. Recently, several experimental studies investigating various aspects of the mechanism using this method have been conducted [45,47,[52][53][54][55]. ...
... Of the five factors listed by Trudgill [11] (see Section 1.1), the two most studied ones are population size [18,28,40,44,47,56] and level of contact. The potential connection between contact intensity or, specifically, between the relative proportions of adult and child learners in the population, and complexity decrease seems to be more straightforward and its descriptions are better fleshed out. ...
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Article
It is often claimed that languages with more non-native speakers tend to become morphologically simpler, presumably because non-native speakers learn the language imperfectly. A growing number of studies support this claim, but there is a dearth of experiments that evaluate it and the suggested explanatory mechanisms. We performed a large-scale experiment which directly tested whether imperfect language learning simplifies linguistic structure and whether this effect is amplified by iterated learning. Members of 45 transmission chains, each consisting of 10 one-person generations, learned artificial mini-languages and transmitted them to the next generation. Manipulating the learning time showed that when transmission chains contained generations of imperfect learners, the decrease in morphological complexity was more pronounced than when the chains did not contain imperfect learners. The decrease was partial (complexity did not get fully eliminated) and gradual (caused by the accumulation of small simplifying changes). Simplification primarily affected double agent-marking, which is more redundant, arguably more difficult to learn and less salient than other features. The results were not affected by the number of the imperfect-learner generations in the transmission chains. Thus, we provide strong experimental evidence in support of the hypothesis that iterated imperfect learning leads to language simplification.
... Interestingly, linguistic research has, in parallel to studies on non-human animal communication, tried to understand the sources for language diversity. In striking contrast with the SCHCC, larger human communities have been predicted to have evolved less complex languages (fewer and less elaborate morphological structures, fewer irregulars, and overall simpler grammars) to ease generalizations and transparency (Lupyan and Dale 2010;Perry et al. 2010;Nettle 2012;Lev-Ari 2016Raviv et al. 2019). This prediction appears in opposition with the SCHCC, as we have seen that in this framework larger groups are predicted to constitute selective pressures for the evolution of more complex communication systems. ...
... Larger communities may favor the evolution of simple, predictable, and structured variants (Perry et al. 2010;Lev-Ari 2016. Languages of large communities would then have more extensive phonological inventories, shorter words, and lower morphological complexity than the language in smaller communities (Nettle 2012). differences between species as well as their phylogenetic relationship (Ramsier et al. 2012;Manser et al. 2014). ...
... Indeed, in linguistics, the similar three issues outlined in chapter I have also been mentioned. First, while speaker population size is the main proxy used for social complexity, its relevance is questioned (Nettle 2012). Second, difficulty to control for alternative hypotheses, as the environment or economic factors are also highlighted, especially as much fewer methods have been developed to take into account the historical relatedness existing between different languages than the phylogeny between different species (Nettle 2012). ...
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Thesis
Animals exhibit an astonishing diversity of communicative systems, with substantial variation in both the nature and the number of signals they produce. Variation in communicative complexity has been conceptually and empirically attributed to social complexity and formalized as the “social-complexity hypothesis for communicative complexity” (SCHCC). Indeed, group-living animals face complex social environments where they engage in a wide range of interactions with different social partners triggering the need for transmission of a broader diversity of messages. In chapter I (Peckre et al. 2019), I review the literature on the current tests of the SCHCC, pointing out and discussing what I identified as the main gaps in the current state of the art. Specifically, three key issues emerged from my analysis. The first issue concerns the operational definition of the main variables, social and communicative complexity. Notably, when defining communicative complexity, most empirical tests of the SCHCC focus on a single modality (e.g., acoustic, visual, olfactory) whereas several good reasons exist for acknowledging the multimodal nature of both, signals and communicative systems in this framework. At the system level, focusing on only one modality may lead to over- or underestimation of the relationship between social and communicative complexity. The second issue relates to the fact that while numerous studies have highlighted a link between social and communicative complexity, their correlative nature does not permit conclusions about the direction of causality. Indeed, alternative hypotheses involving anatomical, phylogenetical, or ecological factors have also been proposed to explain the evolution of more complex forms of communication. Finally, I note that researchers rarely address the actual ways in which social factors directly affect variation in signaling. Indeed, the underlying mechanisms of this link are usually left unexplored, failing to uncover the specific attribute of communication that would be co-evolving with specific aspects of sociality. I, therefore, make a plea for expanding tests of the SCHCC in 1) scope (systematic approach across modalities) and 2) depth (characterization of the observed relationships) as I believe it may significantly advance our understanding of the intricate links between animal sociality and communication. To address point 1), I offer in chapter II a comprehensive approach of the cross-modal communicative systems of two closely related true lemur species having similar morphology, living in similar habitats, but differing in their social systems. I studied wild Eulemur rufifrons and E. mongoz in Madagascar, respectively in Kirindy and Ankatsabe forests for 12 months. I describe a new analytical framework to assess the complexity of signaling systems across modalities. Applying a multimodal approach may help to uncover the different selective pressures acting on the communicative system and to understand better adaptive functions that might be unclear from the study of its separate components independently. E. rufifrons, the species having the more complex social system, also had overall a more complex communicative system than the one of the E. mongoz. Both careful choices of the species to compare to limit the effect of possible additional selective pressures and exploration of the social function of the non-homologous signals allow concluding that this increased complexity of the communicative system in E. rufifrons is most likely associated with social selective pressures. I developed this new analytical framework, partly based on using a cross-modal network approach, with the perspective of facilitating cross-taxonomic comparisons. Moreover, this approach may be combined with new multi-dimensional approaches of social complexity and contribute to a more holistic approach to the tests of the SCHCC. By this, we should be able to derive new testable hypotheses that would contribute to better understand the course of events that have led to the evolution of communication diversity in its distinct dimensions. In chapter III, I address point 2) by investigating the impacts of sociality on the expression of a multimodal signal, the anogenital scent-marking behavior in wild red-fronted lemurs. I specifically investigated intragroup audience effects on anogenital scent-marking behaviors in a wild population of red-fronted lemurs and particularly whether males and females differed in this aspect and if these differences may reveal functional differences associated with anogenital scent-marking across sexes. I found an intragroup audience effect in males but not in females. Males deposited less often anogenital marks when more males were present within a three meters range compared to five- or ten-meters ranges. Males may prefer to reduce the risk of physical contact by avoiding to scent-mark near other males, and/or give priority to other males to scent-mark. With these results, I provide important insights into the functional significance of anogenital scent-marking in red-fronted lemurs and support the idea of greater intragroup social pressures associated with anogenital scent-marking in males than in females in egalitarian species. Studying the flexibility of complex signal usage (e.g., occurrence or structural modifications) across social contexts (audiences) should permit the identification of different individual social characteristics that may elicit or constrain complex signal expression. These social characteristics may later constitute social pressures acting for or against the evolution of these complex signaling behaviors. In chapters IV and V, I also address ethical questions related to this project and the way I tried to adapt and best address my responsibilities for animal welfare. In chapter IV, I expose some technical details and ethical concerns experienced during the choice of my field sites. While in chapter V (Buil and Peckre et al. 2019) I present a remote releasable collar system developed in collaboration with the Neurobiology Laboratory (German Primate Center, Göttingen, Germany) intending to provide a tool to significantly reduce the number of captures in studies using bio-logging for medium-sized mammal species. Overall, by emphasizing the importance of the multimodal nature of communicative systems and the social context in which signals are exchanged, I hope to stimulate the development of new tests of the SCHCC based on this expanded framework. I additionally argue for the importance of looking across research fields since striking parallels may be observed between animal behavior and linguistic research when addressing the origins of communication complexity, be it in the form of human language or animal signaling.
... Almost 7000 languages are spoken around the world [1,2], and the remarkable range of linguistic diversity has been studied extensively [3,4]. Current research focuses on understanding the sources for this diversity, and attempts to understand whether differences between languages can be predicted by differences in their environments [5][6][7][8][9][10][11]. If languages evolved as a means for social coordination [12,13], they are bound to be shaped by their social environment and the properties of the cultures in which they evolved. ...
... In particular, bigger communities tend to be more sparsely connected and more geographically spread out, have more contact with outsiders, and have a higher proportion of adult second language learners [14][15][16]. Each of these factors may contribute to the pattern of reduced complexity, and thus provide an alternative explanation for the correlation between community size and linguistic structure [5][6][7][8]20,21]. In fact, many researchers assume that this correlation is accounted for by the proportion of second language learners in the community [5][6][7]20] or by differences in network connectivity [15][16][17]21] (see discussion). ...
... = 0.09, t = 15.99, p < 0.0001)-a critical assumption in the literature [8,14,16,39] and a premise for our hypothesis. We also quantified the degree of shared history between participants. ...
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Article
Understanding worldwide patterns of language diversity has long been a goal for evolutionary scientists, linguists and philosophers. Research over the past decade has suggested that linguistic diversity may result from differences in the social environments in which languages evolve. Specifically, recent work found that languages spoken in larger communities typically have more systematic grammatical structures. However, in the real world, community size is confounded with other social factors such as network structure and the number of second languages learners in the community, and it is often assumed that linguistic simplification is driven by these factors instead. Here, we show that in contrast to previous assumptions, community size has a unique and important influence on linguistic structure. We experimentally examine the live formation of new languages created in the laboratory by small and larger groups, and find that larger groups of interacting participants develop more systematic languages over time, and do so faster and more consistently than small groups. Small groups also vary more in their linguistic behaviours, suggesting that small communities are more vulnerable to drift. These results show that community size predicts patterns of language diversity, and suggest that an increase in community size might have contributed to language evolution.
... We also remark that the second overdispersion measure is less sensitive than the first: however, it turns out that this is easier to calculate for individualbased models, and we will take a large deviation of this measure from 1 as providing a strong indication of a poor fit to the data. It is remarkable that this simple model seems to provide a reasonably good fit to the data, particularly in view of an ongoing discussion about the role of population size in language structure and change [64][65][66][67] (a point we return to in the Discussion). The Poisson model explicitly assumes that the phenomenological rate of change � o is constant across all populations, and that each language change is able to propagate rapidly from origination to fixation. ...
... A detailed record of the history of each feature of interest across many languages is required for a conclusive assessment, data that is difficult to obtain (particularly for more stable features, where greater time depth is required to see a sufficiently large number of changes). However, a number of studies that have directly examined the relationship between population size and various aspects of language structure or change [64][65][66][67] have tended to conclude that where there is an effect, it is weak. For example, [67] reports rates of gain and loss that scale sublinearly with the population size, consistent with the behaviour of Wright-Fisher models on heterogeneous social networks. ...
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Article
Languages emerge and change over time at the population level though interactions between individual speakers. It is, however, hard to directly observe how a single speaker’s linguistic innovation precipitates a population-wide change in the language, and many theoretical proposals exist. We introduce a very general mathematical model that encompasses a wide variety of individual-level linguistic behaviours and provides statistical predictions for the population-level changes that result from them. This model allows us to compare the likelihood of empirically-attested changes in definite and indefinite articles in multiple languages under different assumptions on the way in which individuals learn and use language. We find that accounts of language change that appeal primarily to errors in childhood language acquisition are very weakly supported by the historical data, whereas those that allow speakers to change incrementally across the lifespan are more plausible, particularly when combined with social network effects.
... Indeed, a recent observational study found a strong correlation between the popularity of a label and the likelihood of this label gaining future adoption in a population, hinting at the possibility that population dynamics amplified their likelihood of spreading (Pagel et al. 2019). Even in the anthropological data on crosscultural category convergence, population size is a significant positive predictor of similarities in the size, structure, and content of category systems (Brown 1984;Fay and Ellison 2013;Fay, Garrod, and Roberts 2008;Nettle 2012;Witkowski and Burris 1981). ...
... Further consistent with the Fisher-Wright model, it has been found that terminologies used in small populations are subject to higher levels of idiosyncrasy and variation (Boone 1949;Bowern 2010;Nettle 1999Nettle , 2012Pagel et al. 2007). Altogether, these studies point to the prediction that communication in small social groups can, contrary to the nativist position, lead to highy divergent, path dependent category systems for novel continuous domains, whereas large social groups can generate predictable evolutionary trajectories, leading to similar category systems in terms of both size and content. ...
Article
Category systems are remarkably consistent across societies. Stable partitions for concepts relating to flora, geometry, emotion, color, and kinship have been repeatedly discovered across diverse cultures. Canonical theories in cognitive science argue that this form of convergence across independent populations, referred to as ‘cross-cultural convergence’, is evidence of innate human categories that exist independently of social interaction. However, a number of studies have shown that even individuals from the same population can vary substantially in how they categorize novel and ambiguous phenomena. Contrary to findings on cross-cultural convergence, this individual variation in categorization processes suggests that independent populations should evolve highly divergent category systems (as is often predicted by theories of social constructivism). These puzzling findings raise new questions about the origins of cross-cultural convergence. In this dissertation, I develop a new mathematical approach to cultural processes of category formation, which shows that whether or not independent populations create similar category systems is a function of population size. Specifically, my model shows that small populations frequently diverge in their category systems, whereas in large populations, a subset of categories consistently reach critical mass and spread, leading to convergent cultural trajectories. I test and confirm this prediction in a large-scale online social network experiment where I study how small and large social networks construct original category systems for a continuum of novel and ambiguous stimuli. I conclude by discussing the implications of these results for networked crowdsourcing, which harnesses coordination in communication networks to enhance content management and generation across a wide range of domains, including content moderation over social media and scientific classification in citizen science.
... It is remarkable that this simple model seems to provide a reasonably good fit to the data, particularly in view of an ongoing discussion about the role of population size in language structure and change [64][65][66][67] (a point we return to in the Discussion). The Poisson model explicitly assumes that the phenomenological rate of changeω is constant across all populations, and that each language change is able to propagate rapidly from origination to fixation. ...
... A detailed record of the history of each feature of interest across many languages is required for a conclusive assessment, data that is difficult to obtain (particularly for more stable features, where greater time depth is required to see a sufficiently large number of changes). However, a number of studies that have directly examined the relationship between population size and various aspects of language structure or change [64][65][66][67] have tended to conclude that where there is an effect, it is weak. For example, [67] reports rates of gain and loss that scale sublinearly with the population size, consistent with the behaviour of Wright-Fisher models on heterogeneous social networks. ...
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Preprint
Languages emerge and change over time at the population level though interactions between individual speakers. It is, however, hard to directly observe how a single speaker's linguistic innovation precipitates a population-wide change in the language, and many theoretical proposals exist. We introduce a very general mathematical model that encompasses a wide variety of individual-level linguistic behaviours and provides statistical predictions for the population-level changes that result from them. This model allows us to compare the likelihood of empirically-attested changes in definite and indefinite articles in multiple languages under different assumptions on the way in which individuals learn and use language. We find that accounts of language change that appeal primarily to errors in childhood language acquisition are very weakly supported by the historical data, whereas those that allow speakers to change incrementally across the lifespan are more plausible, particularly when combined with social network effects.
... In some domains, typically involving morphological complexity and grammatical irregularities of various kinds, there is actually evidence for an inverse correlation: as argued by McWhorter [8,9,[13][14][15], Dahl [4], Wray & Grace [16], Lupyan & Dale [17], Trudgill [18], Nettle [19] and others, larger political entities, typically associated with various modes of exoteric communication, and in particular imperfect adult second-language acquisition, are conducive to linguistic simplification, whereas smaller societies, generally characterized by more esoteric forms of communication, are fertile grounds for the accretion of linguistic complexity. Nevertheless, in a variety of other domains, evidence emerges in support of the Complexity Covariance Hypothesis. ...
... Similarly, in sign languages, Meir et al. [23] and Ergin et al. [24] argue that an increase in the size of the signing community entails a greater degree of conventionalization. In phonology, Hay & Bauer [25], Atkinson [26], Wichmann et al. [27] and Nettle [19] argue that larger languages tend to have larger phonemic inventories than smaller languages. In the domain of metaphor comprehension, Gil & Shen [28] present evidence to the effect that more highly complex polities tend to be associated with languages whose metaphors are of more complex directional structure. ...
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Article
This paper proposes a Complexity Covariance Hypothesis, whereby linguistic complexity covaries with cultural and socio-political complexity, and argues for an Evolutionary Inference Principle, in accordance with which, in domains where linguistic complexity correlates positively with cultural/socio-political complexity, simpler linguistic structures are evolutionarily prior to their more complex counterparts. Applying this methodology in a case study, the covariance of linguistic and cultural/socio-political complexity is examined by means of a cross-linguistic survey of tense–aspect–mood (TAM) marking in a worldwide sample of 868 languages. A novel empirical finding emerges: all else being equal, languages from small language families tend to have optional TAM marking, while languages from large language families are more likely to exhibit obligatory TAM marking. Since optional TAM marking is simpler than obligatory TAM marking, it can, therefore, be inferred that optional TAM marking is evolutionarily prior to obligatory TAM marking: a living fossil. In conclusion, it is argued that the presence of obligatory TAM marking, correlated with the more highly grammaticalized expression of thematic-role assignment, is a reflection of a deeper property of grammatical organization, namely, the grammaticalization of predication. Thus, it is suggested that the development of agriculture and resulting demographic expansions, resulting in the emergence of large language families, are a driving force in the evolution of predication in human language. This article is part of the theme issue ‘Reconstructing prehistoric languages’.
... 8: 200895 reflect three major dimensions of system complexity: diversity, flexibility and combinability. Much effort has been devoted to assessing the diversity of organisms and organizations by measuring the number and variety of their building blocks [4,6,[28][29][30]. However, diversity is only one component of complexity and we still lack indices capable of capturing the full extent of complexity. ...
... Richness is the number of possible outcomes, i.e. types or categories of a variable. It is a popular measure of diversity/complexity as it is relatively easy to count cell types in organisms [31], species in ecological communities [32], signals in animal communication [13,29], structures in languages [28] or cultural variants in human societies [6,33]. Evenness refers to the heterogeneity of probability of the different categories composing the richness, whether structural or functional. ...
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Article
While there is no consensus about the definition of complexity, it is widely accepted that the ability to produce uncertainty is the most prominent characteristic of complex systems. We introduce new metrics that purport to quantify the complexity of living organisms and social organizations based on their levels of uncertainty. We consider three major dimensions regarding complexity: diversity based on the number of system elements and the number of categories of these elements; flexibility which bears upon variations in the elements; and combinability which refers to the patterns of connection between elements. These three dimensions are quantified using Shannon's uncertainty formula, and they can be integrated to provide a tripartite complexity index. We provide a calculation example that illustrates the use of these indices for comparing the complexity of different social systems. These indices distinguish themselves by a theoretical basis grounded on the amount of uncertainty, and the requirement that several aspects of the systems be accounted for to compare their degree of complexity. We expect that these new complexity indices will encourage research programmes aiming to compare the complexity levels of systems belonging to different realms.
... Nevertheless, it receives indirect support from the literature on second language learning, which demonstrates that adults generally struggle with learning and using morphology in a second language: adults L2 speakers typically show optional or variable use of verbal and nominal inflections related to case marking, tense, agreement, aspect, and gender marking (DeKeyser, 2005;Haznedar, 2006;Parodi, Schwartz, & Clahsen, 2004), and learn faster when languages exhibit more reliable morphological cues (Kempe & MacWhinney, 1998). An alternative explanation for the documented correlation between morphological complexity and community size is that, instead of being mediated by the proportion of adult non-native speakers and their difficulty in language learning, it is directly derived from differences in community size (Nettle, 2012;Raviv et al., 2019b;Wray and Grace, 2007). According to this hypothesis, the total number of speakers in the community can affect language structure during peer-to-peer diffusion, and there is no need to assume the prevalence of second language learning as a mediating factor: big communities might favor simpler and more transparent linguistic structures simply because they are big. ...
... Nevertheless, they need to be able to understand each other when interacting for the first time. As such, it was argued that members of bigger communities are under a stronger pressure to develop transparent, predictable, and systematic structures that aid convergence and allow strangers to successfully communicate (Nettle, 2012;Wray and Grace, 2007;Raviv et al., 2019b). Although we cannot draw any direct causal inferences from the current study, our findings support this hypothesis by showing that the benefits of systematic linguistic structure go beyond learnability, and that systematicity can aid communication and productivity in general language use. ...
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Article
Cross-linguistic differences in morphological complexity could have important consequences for language learning. Specifically, it is often assumed that languages with more regular, compositional, and transparent grammars are easier to learn by both children and adults. Moreover, it has been shown that such grammars are more likely to evolve in bigger communities. Together, this suggests that some languages are acquired faster than others, and that this advantage can be traced back to community size and to the degree of systematicity in the language. However, the causal relationship between systematic linguistic structure and language learnability has not been formally tested, despite its potential importance for theories on language evolution, second language learning, and the origin of linguistic diversity. In this pre-registered study, we experimentally tested the effects of community size and systematic structure on adult language learning. We compared the acquisition of different yet comparable artificial languages that were created by big or small groups in a previous communication experiment, which varied in their degree of systematic linguistic structure. We asked (a) whether more structured languages were easier to learn; and (b) whether languages created by the bigger groups were easier to learn. We found that highly systematic languages were learned faster and more accurately by adults, but that the relationship between language learnability and linguistic structure was typically non-linear: high systematicity was advantageous for learning, but learners did not benefit from partly or semi-structured languages. Community size did not affect learnability: languages that evolved in big and small groups were equally learnable, and there was no additional advantage for languages created by bigger groups beyond their degree of systematic structure. Furthermore, our results suggested that predictability is an important advantage of systematic structure: participants who learned more structured languages were better at generalizing these languages to new, unfamiliar meanings, and different participants who learned the same more structured languages were more likely to produce similar labels. That is, systematic structure may allow speakers to converge effortlessly, such that strangers can immediately understand each other.
... According to this hypothesis, often referred to as the Linguistic Niche Hypothesis, the structure of languages is shaped by the structure of the community in which they evolved. Research in the past decades supports this theory by showing that different types of languages tend to develop in different types of societies (Bentz & Winter, 2013;Lupyan & Dale, 2010;Meir, Israel, Sandler, Padden, & Aronoff, 2012;Nettle, 1999Nettle, , 2012Raviv, Meyer, & Lev-Ari, 2019b;Reali, Chater, & Christiansen, 2018). ...
... Exoteric languages tend to have fewer and less elaborate morphological paradigms, and they are more likely to express various grammatical relations (e.g., negation, future tense) by using lexical forms (individual words) rather than inflections (affixes). That is, there seems to be a greater pressure for creating simpler and more systematic languages in exoteric compared to esoteric settings (Nettle, 2012;Trudgill, 2009;Wray & Grace, 2007). This is presumably because (a) members of exoteric communities are more likely to interact with strangers, resulting in a communicative pressure in favor of generalization and transparency, and (b) there is a relatively high proportion of adult second language learners in exoteric communities, who often struggle with learning complex and opaque morphologies. ...
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Article
Social network structure has been argued to shape the structure of languages, as well as affect the spread of innovations and the formation of conventions in the community. Specifically, theoretical and computational models of language change predict that sparsely connected communities develop more systematic languages, while tightly knit communities can maintain high levels of linguistic complexity and variability. However, the role of social network structure in the cultural evolution of languages has never been tested experimentally. Here, we present results from a behavioral group communication study, in which we examined the formation of new languages created in the lab by micro‐societies that varied in their network structure. We contrasted three types of social networks: fully connected, small‐world, and scale‐free. We examined the artificial languages created by these different networks with respect to their linguistic structure, communicative success, stability, and convergence. Results did not reveal any effect of network structure for any measure, with all languages becoming similarly more systematic, more accurate, more stable, and more shared over time. At the same time, small‐world networks showed the greatest variation in their convergence, stabilization, and emerging structure patterns, indicating that network structure can influence the community's susceptibility to random linguistic changes (i.e., drift).
... Simplification has been suggested to stem from a high number of second-language learners (Bentz and Winter 2013;Trudgill 2011). At the same time, languages relying largely on the context and less on explicit coding of grammatical information, such as those found in Mainland Southeast Asia, as well as languages requiring high levels of obligatory grammatical marking, which might seem redundant, have all been claimed to have the same expressive potential (Parkvall 2008: 267;Nettle 2012Nettle : 1834. Since trade-offs do not seem to be prerequisites for successful language transmission, it is not surprising that we do not find strong evidence for large-scale compensatory relationships. ...
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Article
Nouns and verbs are known to differ in the types of grammatical information they encode. What is less well known is the relationship between verbal and nominal coding within and across languages. The equi-complexity hypothesis holds that all languages are equally complex overall, which entails trade-offs between coding in different domains. From a diachronic point of view, this hypothesis implies that the loss and gain of coding in different domains can be expected to balance each other out. In this study, we test to what extent such inverse coevolution can be observed in a sample of 244 languages, using data from a comprehensive cross-linguistic database (Grambank) and applying computational phylogenetic modelling to control for genealogical relatedness. We find evidence for coevolutionary relationships between specific features within nominal and verbal domains on a global scale, but not for overall degrees of grammatical coding between languages. Instead, these amounts of nominal and verbal coding are positively correlated in Sino-Tibetan languages and inversely correlated in Indo-European languages. Our findings indicate that accretion and loss of grammatical information in nominal words and verbs are lineage-specific.
... Space limitations do not allow for a detailed discussion of how Brazilian Portuguese became so different; suffice to say that it was the result of an almost total disregard for education from colonial to modern times combined with prolonged and extensive (a) contact with other languages, (b) acquisition as a second language by adult speakers (mainly indigenous peoples, African slaves, and foreign immigrants), (c) regular exponential increases in the number of native speakers, and (d) dialect mixing and koinéisation due to population migrations. The linguistics literature is clear in predicting the outcome of such social circumstances: rapid and, at times, transformative linguistic change, particularly towards the simplification of the inflectional morphology (Bentz, Verkerk, Kiela, Hill, & Buttery, 2015;Bentz & Winter, 2013;Lupyan & Dale, 2010;McWhorter, 2007;Nettle, 2012;Nichols & Bentz, 2017;Trudgill, 1986Trudgill, , 2001Trudgill, , 2010Trudgill, , 2011) and complexification of the phonology as a marker of local identity. ...
... It should be emphasized that the model presented and analysed in this paper is concerned with only one potential external ("environmental") predictor of contact-induced change, namely the proportion of L2 speakers in a speech community. Other possible external factors conditioning language change have been considered in the literature, ranging from population size (Lupyan & Dale 2010;Nettle 2012;Koplenig 2019) to social network geometries (Ke & Gong & Wang 2008;Fagyal et al. 2010;Kauhanen 2017;Josserand et al. 2021) or combinations of such parameters (Trudgill 2004). Although the present model sets such effects aside, this is not to deny their importance. ...
... In fact, research concerning phonological complexity has not produced clear and consistent results regarding the role of community size. A number of studies have found the opposite of Trudgill's claim, namely a positive correlation between community size and size of the phoneme inventory (see Nettle, 2012 and references therein), but Moran et al. (2012) argue against those findings. With respect to the lexicon it seems that the picture is rather clear: bigger languages with standardized forms, developed literacy and covering all functional domains have a larger lexicon (Reali et al., 2018), but there are no studies that consider other types of semantic complexity. ...
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Book
The question whether all languages are similarly complex is at the centre of some of the most heated debates within linguistics. These debates focus on such issues as the universality of syntactic recursion, the exceptional simplicity of creole languages, complexity trade-offs between structural levels, as well as sociolinguistic correlates of complexity profiles. Discussions concerning complexity have implications that go far beyond linguistics in the narrow sense, including e.g. the role of nature vs. nurture in human cognition and culture, or the distinction between message and noise in information theory. In consequence, debates on linguistic complexity shape our perception of human nature and variation among human populations. In this Research Topic, we investigate the motivations driving the research on linguistic complexity. Thus, Menzerath’s law about complexity trade-offs was inspired by bottom-up empirical observations. By contrast, the claim about the universality of syntactic recursion was primarily informed by theoretical considerations. Due to its normative dimension, the notion of complexity has also served as a vehicle for advancing ideological agendas, such as characterizing speakers as more or less advanced based on perceived properties of their languages. By bringing these perspectives together, we contribute to a critical assessment of how linguistic research is motivated by both epistemic and non-epistemic goals.
... Richness is the number of possible outcomes, types, or categories of a variable. It is a popular measure of diversity/complexity as it is relatively easy to count cell types in organisms (Valentine et al., 1994), species in ecological communities (Peet, 1974), signals in animal communication (Freeberg et al., 2012;, structures in languages (Nettle, 2012), or cultural variants in human societies (Carneiro, 2003). Evenness refers to the heterogeneity of probability of the different types composing the richness, whether structural or functional. ...
Thesis
The social complexity hypothesis posits that living in a complex social system requires complex communication skills. Complexity and uncertainty being linked, I have tested this hypothesis by comparing several primate species that differ by the degree of uncertainty of their social interactions. First, I elaborated tools to measure three components of system complexity (diversity, flexibility, combinability). I developed a procedure to objectively assess diversity and flexibility using clustering algorithms.Then, I used this method to study the vocalisations emitted by adult females in four species of macaques: two tolerant species (Tonkean & crested macaques) and two intolerant species (Japanese & rhesus macaques). I found marked contrasts between these two pairs of species in terms of diversity and flexibility of vocal signals, with different degrees of freedom in the association between acoustic structure and context depending on the species. These results support the social complexity hypothesis by showing that animals that experience more uncertain social interactions also show a greater richness of communication signals.
... Population size is a core parameter defining the social environment an agent interacts with. Its impact on language structures has largely been studied on humans (Nettle, 2012;Bromham et al., 2015;Reali et al., 2018;Raviv et al., 2019a) and animals (Blumstein & Armitage, 1997;McComb & Semple, 2005;Wilkinson, 2013). By analyzing 2000 languages (Dryer & Haspelmath, 2013), a clear correlation was drawn between population size and diverse language features, e.g. ...
Preprint
Populations have often been perceived as a structuring component for language to emerge and evolve: the larger the population, the more structured the language. While this observation is widespread in the sociolinguistic literature, it has not been consistently reproduced in computer simulations with neural agents. In this paper, we thus aim to clarify this apparent contradiction. We explore emergent language properties by varying agent population size in the speaker-listener Lewis Game. After reproducing the experimental difference, we challenge the simulation assumption that the agent community is homogeneous. We first investigate how speaker-listener asymmetry alters language structure to examine two potential diversity factors: training speed and network capacity. We find out that emergent language properties are only altered by the relative difference of learning speeds between speaker and listener, and not by their absolute values. From then, we leverage this observation to control population heterogeneity without introducing confounding factors. We finally show that introducing such training speed heterogeneities naturally sort out the initial contradiction: larger simulated communities start developing more stable and structured languages.
... Larger groups create more compositional languages. Socio-demographic factors such as population size have long been assumed to be important determinants of language evolution (Wray & Grace, 2007;Nettle, 2012;Lupyan & Dale, 2010). Specifically, global cross-linguistic studies found that bigger communities tend to have languages with more systematic and transparent structures (Lupyan & Dale, 2010). ...
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Preprint
Emergent communication protocols among humans and artificial neural network agents do not yet share the same properties and show some critical mismatches in results. We describe three important phenomena with respect to the emergence and benefits of compositionality: ease-of-learning, generalization, and group size effects (i.e., larger groups create more systematic languages). The latter two are not fully replicated with neural agents, which hinders the use of neural emergent communication for language evolution research. We argue that one possible reason for these mismatches is that key cognitive and communicative constraints of humans are not yet integrated. Specifically, in humans, memory constraints and the alternation between the roles of speaker and listener underlie the emergence of linguistic structure, yet these constraints are typically absent in neural simulations. We suggest that introducing such communicative and cognitive constraints would promote more linguistically plausible behaviors with neural agents.
... (Dor & Jablonka, 2014, p. 16) Languages are often shaped by the communicative demands of different social environments. For example, languages that are more exoteric-with larger speaker populations, greater geographical spread, and more contact with other languages-have simpler morphologies and larger phonological inventories (Lupyan & Dale, 2010;Nettle, 2012). These characteristics appear to be shaped by the communicative pressures of exoteric groups, in which more frequent interactions between strangers and a greater proportion of second language adult learners require simpler and more systematic language structures. ...
Article
Theories of music evolution rely on our understanding of what music is. Here, I argue that music is best conceptualized as an interactive technology, and propose a coevolutionary framework for its emergence. I present two basic models of attachment formation through behavioral alignment applicable to all forms of affiliative interaction and argue that the most critical distinguishing feature of music is entrained temporal coordination. Music's unique interactive strategy invites active participation and allows interactions to last longer, include more participants, and unify emotional states more effectively. Regarding its evolution, I propose that music, like language, evolved in a process of collective invention followed by genetic accommodation. I provide an outline of the initial evolutionary process which led to the emergence of music, centered on four key features: technology, shared intentionality, extended kinship, and multilevel society. Implications of this framework on music evolution, psychology, cross-species and cross-cultural research are discussed.
... At the same time, there is now a fair amount of evidence indicating that the size of a language community correlates inversely with the grammatical -notably morphological -complexity of its language, and investigations are ongoing into the possible causal mechanisms involved (Wray & Grace 2007;Lupyan & Dale 2010;Nettle 2012;Atkinson et al. 2015;Reali et al. 2018;Raviv et al. 2019). ...
Full-text available
Chapter
Kanashi is an indigenous language of India spoken by some 2,000 individuals in one single village in the Indian Himalayas. It is a Sino-Tibetan language, separated from the other Sino-Tibetan speaking communities in the region by a girdle of Indo-Aryan speaking villages. In the present volume we contribute to the documentation of Kanashi with a phonological and a grammatical description, as well as a basic vocabulary. We also address questions of genealogical classification of the Sino-Tibetan languages of the Himalayas, as well as their history of contact with other language families.
... Creating a more complex version for adults could help us clarify whether they indeed benefit less from redundant cues, but would prevent the direct comparison between them and child learners. While various researchers agree that adult learning is a key factor in explaining the simplification of language (Bentz & Winter, 2013;Dahl, 2004;Nettle, 2012;Trudgill, 2011;Wray & Grace, 2007), the question of what gives rise to complexity in the first place is less clear (Lupyan & Dale, 2010;Trudgill, 2011). Under the LNH account, the answer lies in child learners: Child learners are predicted to benefit from redundancy, leading in turn to the creation and preservation of redundancy for languages used by communities with more child learners. ...
Preprint
The prevalence of redundancy in the world languages has long puzzled language researchers. It is especially surprising in light of the growing evidence on speakers' tendency to avoid redundant elements in production (omitting or reducing more predictable elements). Here, we propose that redundancy can be functional for learning. In particular, we argue that redundant cues can facilitate learning, even when they make the language system more complicated. This prediction is further motivated by the Linguistic Niche Hypothesis (Lupyan & Dale, 2010), which suggests that morphological complexity can arise due to the advantage redundancy might confer for child learners. We test these hypotheses in an artificial language learning study with children and adults, where either word order alone or both word order and case marking serve as cues for thematic assignment in a novel construction. We predict, and find, that children learning the redundant language learn to produce it, and show better comprehension of the novel thematic assignment than children learning the non-redundant language, despite having to learn an additional morpheme. Children in both conditions were similarly accurate in producing the novel word order, suggesting redundancy might have a differential effect on comprehension and production. Adults did not show better learning in the redundant condition, most likely because they were at ceiling in both conditions. We discuss implications for theories of language learning and language change.
... Creating a more complex version for adults could help us clarify whether they indeed benefit less from redundant cues, but would prevent the direct comparison between them and child learners. While various researchers agree that adult learning is a key factor in explaining the simplification of language (Bentz & Winter, 2013;Dahl, 2004;Nettle, 2012;Trudgill, 2011;Wray & Grace, 2007), the question of what gives rise to complexity in the first place is less clear (Lupyan & Dale, 2010;Trudgill, 2011). Under the LNH account, the answer lies in child learners: Child learners are predicted to benefit from redundancy, leading in turn to the creation and preservation of redundancy for languages used by communities with more child learners. ...
Article
The prevalence of redundancy in the world languages has long puzzled language researchers. It is especially surprising in light of the growing evidence on speakers' tendency to avoid redundant elements in production (omitting or reducing more predictable elements). Here, we propose that redundancy can be functional for learning. In particular, we argue that redundant cues can facilitate learning, even when they make the language system more complicated. This prediction is further motivated by the Linguistic Niche Hypothesis (Lupyan & Dale, 2010), which suggests that morphological complexity can arise due to the advantage redundancy might confer for child learners. We test these hypotheses in an artificial language learning study with children and adults, where either word order alone or both word order and case marking serve as cues for thematic assignment in a novel construction. We predict, and find, that children learning the redundant language learn to produce it, and show better comprehension of the novel thematic assignment than children learning the non-redundant language, despite having to learn an additional morpheme. Children in both conditions were similarly accurate in producing the novel word order, suggesting redundancy might have a differential effect on comprehension and production. Adults did not show better learning in the redundant condition, most likely because they were at ceiling in both conditions. We discuss implications for theories of language learning and language change.
... Population size and contact in particular have been shown to affect linguistic structure. Languages used by larger communities, covering larger geographical areas with a higher degree of contact with other languages, tend to be simpler than those used in smaller, more close-knit populations [4,[20][21][22][23][24][25][26][27][28][29][30]. This has been suggested to derive from the presence of adult, non-native language learners [4,31]. ...
Article
Language is the primary repository and mediator of human collective knowledge. A central question for evolutionary linguistics is the origin of the combinatorial structure of language (sometimes referred to as duality of patterning), one of language’s basic design features. Emerging sign languages provide a promising arena to study the emergence of language properties. Many, but not all such sign languages exhibit combinatoriality, which generates testable hypotheses about its source. We hypothesize that combinatoriality is the inevitable result of learning biases in cultural transmission, and that population structure explains differences across languages. We construct an agent-based model with population turnover. Bayesian learning agents with a prior preference for compressible languages (modelling a pressure for language learnability) communicate in pairs under pressure to reduce ambiguity. We include two transmission conditions: agents learn the language either from the oldest agent or from an agent in the middle of their lifespan. Results suggest that (1) combinatoriality emerges during iterated cultural transmission under concurrent pressures for simplicity and expressivity and (2) population dynamics affect the rate of evolution, which is faster when agents learn from other learners than when they learn from old individuals. This may explain its absence in some emerging sign languages. We discuss the consequences of this finding for cultural evolution, highlighting the interplay of population-level, functional and cognitive factors. This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.
... Similarly, Mehr and colleagues (seem to) expect more elaborated forms of music in multi-level societies. Considering again the domain of evolutionary linguistics, and briefly summarizing a vast body of research (e.g., Bolender, 2007;Nettle, 2012;Trudgill, 2011;Wray & Grace, 2007), one finds that the languages spoken by small, isolated human groups forming close-knit social networks exhibit quite the opposite structural features (from grammar, to vocabulary, to sound patterns) to the languages spoken by large human groups forming extensive and complex social networks with higher rates of cultural exchange ( Fig. 1; stages 3 and 4, respectively). These opposite features seemingly result from the dissimilar amount of knowledge shared by speakers (i.e., the common ground), in turn a consequence of the different nature of the social bonds they maintain, in turn a consequence of the levels of reactive and proactive aggression, an aspect that is at the core of the self-domestication hypothesis (see also Fig. 1). ...
Article
Savage et al. argue for musicality as having evolved for the overarching purpose of social bonding. By way of contrast, we highlight contemporary predictive processing models of human cognitive functioning in which the production and enjoyment of music follows directly from the principle of prediction error minimization.
... Similarly, Mehr and colleagues (seem to) expect more elaborated forms of music in multi-level societies. Considering again the domain of evolutionary linguistics, and briefly summarizing a vast body of research (e.g., Bolender, 2007;Nettle, 2012;Trudgill, 2011;Wray & Grace, 2007), one finds that the languages spoken by small, isolated human groups forming close-knit social networks exhibit quite the opposite structural features (from grammar, to vocabulary, to sound patterns) to the languages spoken by large human groups forming extensive and complex social networks with higher rates of cultural exchange ( Fig. 1; stages 3 and 4, respectively). These opposite features seemingly result from the dissimilar amount of knowledge shared by speakers (i.e., the common ground), in turn a consequence of the different nature of the social bonds they maintain, in turn a consequence of the levels of reactive and proactive aggression, an aspect that is at the core of the self-domestication hypothesis (see also Fig. 1). ...
Article
We propose that not social bonding, but rather a different mechanism underlies the development of musicality: being unable to survive alone. The evolutionary constraint of being dependent on other humans for survival provides the ultimate driving force for acquiring human faculties such as sociality and musicality, through mechanisms of learning and neural plasticity. This evolutionary mechanism maximizes adaptation to a dynamic environment.
... Population size is often discussed as a factor which might have influenced patterns of language and cultural evolution (Baldini, 2015;Bromham et al., 2015;Collard, 2013;Greenhill et al., 2018;Koplenig, 2019;Moran et al., 2012;Nettle, 2012;Wichmann et al., 2011; for an overview, see Greenhill, 2014). Linguists have tested hypotheses linking the size of a speaker population to the number of phonemes (Donohue & Nichols, 2011;Hay & Bauer, 2007;Moran et al., 2012;Wichmann et al., 2011), morphological complexity (Lupyan & Dale, 2010), the loss of the nominal case (Bentz & Winter, 2013) and the rates of gain and loss of cognate words for basic vocabulary (Bromham et al., 2015, Greenhill et al., 2018. ...
Article
Aims and objectives/purpose/research questions The paper tests the hypothesis that the larger the population of language speakers, the smaller the number of second languages mastered by these speakers. Design/methodology/approach We match the size of the population of 29 Dagestanian languages and the number of second languages spoken by the speakers of these languages from 54 villages, and run a Poisson mixed effects regression model that predicts the average number of second languages spoken by speakers from first-language communities of different size. Data and analysis Data for this study comes from two sources. The information on the population of Dagestanian languages is based on the digitalized census of 1926. The information on the number of second languages in which the residents of Dagestan are proficient is taken from the database on multilingualism in Dagestan (4032 people). Findings/conclusions The study supports the hypothesis that the size of language population is negatively correlated with the multilingualism of the language community. Originality The paper is the first to test the correlation between the size of language population and the level of multilingualism of its speakers using statistical methods and a large body of empirical data. Significance and implications Population size is a factor that could have influenced patterns of language evolution. The population is interrelated with other factors, one of which is long-standing multilingualism. The methodological lesson of this research is that there is a difference in the level of multilingualism within a range of populations where the largest was about 120,000 people. Limitations The data is limited to one multilingual region. The revealed correlation probably does not hold for areas where language communities do not interact with their neighbors and even speakers of minority languages can be monolingual, or for the territories where many people migrated and the area where a language is spoken was discontinuous.
... The existence of these pressures should generally result in speech that is redundant enough for hearers to process but efficient enough to permit speakers to expend the least possible amount of effort. Pressures toward efficiency do not entail that a speech community will exclusively or even predominantly tend toward linguistic economy, however, and social factors such as community size appear to affect linguistic complexity (Nettle, 2012;Trudgill, 2004 inter alia). Despite cross-linguistic variation, all languages are fundamentally constrained by human processing and memory limitations, and must permit speakers to differentiate and disambiguate between discourse referents. ...
Full-text available
Thesis
The ability to differentiate old (definite) and new (indefinite) information is necessary for successful human communication (Evans and Levinson, 2009:437). Definite articles are one method of indicating that information is old, but these are present in fewer than half of the world’s languages (Dryer, 2013a). If indicating definiteness in discourse is essential for communicative success, it stands to reason that languages without definite articles communicate this information through alternate means. This dissertation investigates why definite articles might fail to emerge in a language and asks whether or not the use of specific morphosyntactic properties can be used to predict the absence of a definite article. It also asks whether or not alternate cues can be used to predict that a referent will be definite in languages that lack a definite article. To determine whether or not a relationship exists between the use of specific morphosyntactic properties and the emergence of definite articles, I conducted a grammar-mining study of 100 typologically diverse languages. These languages were coded for the presence or absence of ten morphosyntactic properties, including the use of definite articles. Random forest and conditional inference models were used to test whether or not the absence of a definite article could be predicted based on other elements in a language. To determine whether or not alternate cues can be used to predict definiteness, I also conducted corpus studies of Colloquial Jakarta Indonesian and Kalaallisut (West Greenlandic), two languages without articles. Logistic regression, random forest, and conditional inference models were used to determine if language-specific properties could be used to predict whether or not a discourse referent would be definite. The results of this research show that languages with case marking, OV word order, flexible subject order, and ergative or split ergative alignment are less likely than other languages to develop a definite article. They also show that in Colloquial Jakarta Indonesian and Kalaallisut, elements such as word order and case could be used to predict whether or not a referent will be definite, even without the added benefit of context. These results suggest that semantic definiteness can be cued by properties other than definite articles, and that cognitive pressures toward efficiency depress the likelihood of a definite article emerging in the presence of such cues.
... In fact, research concerning phonological complexity has not produced clear and consistent results regarding the role of community size. A number of studies have found the opposite of Trudgill's claim, namely a positive correlation between community size and size of the phoneme inventory (see Nettle, 2012 and references therein), but Moran et al. (2012) argue against those findings. With respect to the lexicon it seems that the picture is rather clear: bigger languages with standardized forms, developed literacy and covering all functional domains have a larger lexicon (Reali et al., 2018), but there are no studies that consider other types of semantic complexity. ...
Full-text available
Article
This paper is concerned with the relationship between complexity and variation. The main goal is to lay out the conceptual foundations and to develop and systematize reasonable hypotheses such as to set out concrete research questions for future investigations. I first compare how complexity and variation have synchronically been studied and what kinds of questions have been asked in those studies. Departing from earlier surveys of different definitions of complexity, here I classify the majority of complexity studies into two broad types based on two ways of defining this concept. The first type determines and measures linguistic complexity by counting numbers of items (e.g., linguistic forms or rules and interactions between forms). The second type makes use of transparency and the principle of One-Meaning–One-Form. In addition, linguistic complexity has been defined by means of concepts from information theory, namely in terms of description length or information content, but those studies are in the minority. Then I define linguistic variation as a situation when two or more linguistic forms have identical or largely identical meaning and it is possible to use either the one or the other variant. Variation can be free or linguistically or socially conditioned. I argue that there is an implicational relationship between complexity of the first type that is defined in terms of numbers of items and variation. Variation is a type of complexity because it implies the existence of more than one linguistic form per meaning. But not every type of complexity involves variation because complexity defined on the basis of transparency does not necessarily imply the existence of more than one form. In the following I discuss extralinguistic factors that (possibly) have an impact on socially conditioned variation and/or complexity and can lead to an increase or decrease of complexity and/or variation. I conclude with suggestions of how to further examine the relationship between complexity and variation.
... Culture exists on the social network, 17 and cultural evolution should be responsive to network properties such as population size, structure, and dynamic turnover. 4,[18][19][20][21][22] Larger population sizes have been linked to elevated cultural diversity, innovation, and faithful transmission. 18,[23][24][25][26] Conversely, population decline and fragmentation can reduce trait diversity and complexity, as observed in bird song. ...
Full-text available
Article
Culture, defined as socially transmitted information and behaviors that are shared in groups and persist over time, is increasingly accepted to occur across a wide range of taxa and behavioral domains.1 While persistent, cultural traits are not necessarily static, and their distribution can change in frequency and type in response to selective pressures, analogous to that of genetic alleles. This has led to the treatment of culture as an evolutionary process, with cultural evolutionary theory arguing that culture exhibits the three fundamental components of Darwinian evolution: variation, competition, and inheritance.2-5 Selection for more efficient behaviors over alternatives is a crucial component of cumulative cultural evolution,6 yet our understanding of how and when such cultural selection occurs in non-human animals is limited. We performed a cultural diffusion experiment using 18 captive populations of wild-caught great tits (Parus major) to ask whether more efficient foraging traditions are selected for, and whether this process is affected by a fundamental demographic process-population turnover. Our results showed that gradual replacement of individuals with naive immigrants greatly increased the probability that a more efficient behavior invaded a population's cultural repertoire and outcompeted an established inefficient behavior. Fine-scale, automated behavioral tracking revealed that turnover did not increase innovation rates, but instead acted on adoption rates, as immigrants disproportionately sampled novel, efficient behaviors relative to available social information. These results provide strong evidence for cultural selection for efficiency in animals, and highlight the mechanism that links population turnover to this process.
... The human language is amazingly complex and varies, with humans expressing their opinions, perceptions, and thoughts in infinite ways, both through oral and written language [1]. Not only there exist hundreds of languages and dialects globally, but each language has a unique set of rules regarding its grammar, syntax, terms, and words. ...
Full-text available
Conference Paper
One of the main elements in several application domains, such as policy making, addresses the scope of public opinion analysis. The latter is recently realized through sentiment analysis and Natural Language Processing, for identifying and extracting subjective information from raw texts. An additional challenge refers to the exploitation and correlation of data from different languages, in order to analyse sentiments by considering all available information in a holistic way. This paper investigates the impact of Neural Machine Translation in sentiment analysis, based on the translation of text for which neural sentiment analysis in English has been already applied and is applied again on the translated German and Greek texts. The latter is performed through the same Neural Network models that were used in the original language, in order to analyse the differences between the performed neural sentiment analysis on the source and the target languages. The outcomes of the proposed approach have a twofold interpretation. While, it is concluded that modern Neural Machine Translation tools are mature enough to provide high accuracy translations and have minor impact on multilingual sentiment analysis, on the other hand it is shown that additional research should be performed on the multilingualism that pre-trained Word Embeddings can provide.
... Thus, d 0 (q = 0) provides a relatively rough measure of phonotactic complexity, while d 1 (q = 1) is more fine-grained since it also captures token frequency. We have chosen these two measures of complexity, since d 0 is a standard measure of the complexity of phonological systems (Nettle, 1995(Nettle, , 2012Rama, 2013;Wichmann et al., 2011) and functions as a straightforward analogue of lexicon size. Moreover, d 1 is closely related with Shannon entropy, which itself was studied on the lexical level in relation with corpus size (Febres, Jaffé, & Gershenson, 2015). ...
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Article
Two prominent statistical laws in language and other complex systems are Zipf’s law and Heaps’ law. We investigate the extent to which these two laws apply to the linguistic domain of phonotactics—that is, to sequences of sounds. We analyze phonotactic sequences with different lengths within words and across word boundaries taken from a corpus of spoken English (Buckeye). We demonstrate that the expected relationship between the two scaling laws can only be attested when boundary spanning phonotactic sequences are also taken into account. Furthermore, it is shown that Zipf’s law exhibits both high goodness-of-fit and a high scaling coefficient if sequences of more than two sounds are considered. Our results support the notion that phonotactic cognition employs information about boundary spanning phonotactic sequences.
... Bisang 2004;Trudgill 1998Trudgill , 2011. The first set of empirical testing has provided some evidence that, for instance, morphological complexity correlates with the number of native speakers (henceforth, L1 speakers) or with the proportion of second language speakers (henceforth, L2 speakers) (see the reviews by Ladd et al. 2015 andNettle 2012 andreferences there). ...
Full-text available
Article
This paper brings together typological and sociolinguistic approaches to language variation. Its main aim is to evaluate the relative effect of language internal and external factors on the number of cases in the world’s languages. I model word order as a language internal predictor; it is well-known that, for instance, languages with verb-final word order (that is, languages in which both nominal arguments precede the main lexical verb) tend to develop complex case systems more often than languages with SVO word order do. I model population size and the proportion of second language speakers in the speech community as sociolinguistic predictors; these factors have been suggested recently to influence the distribution of the number of cases in the world’s languages. Modelling the data with generalized linear mixed effects modelling suggests an interaction between the number of cases, word order, and the proportion of second language speakers on the one hand, and between the number of cases, word order, and population size, on the other. This kind of complex interactions have not been previously reported in typological research wherefore they call for more complex explanations than previously suggested for cross-linguistic variation.
... While this visualisation may look complicated, in tandem with the interactive features of the website it provides a way of systematically thinking about different explanations. For example, Nettle (2012) and Cuskley and Loreto (2016)'s explanation involves general processes, whereby larger populations change frequency distributions in ways that lead to simplification. In contrast, Wray and Grace (2007) and Little (2012) suggest that there are specific effects of the way adults simplify their speech when talking to strangers. ...
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Article
Language is one of the most complex of human traits. There are many hypotheses about how it originated, what factors shaped its diversity, and what ongoing processes drive how it changes. We present the Causal Hypotheses in Evolutionary Linguistics Database (CHIELD, https://chield.excd.org/), a tool for expressing, exploring, and evaluating hypotheses. It allows researchers to integrate multiple theories into a coherent narrative, helping to design future research. We present design goals, a formal specification, and an implementation for this database. Source code is freely available for other fields to take advantage of this tool. Some initial results are presented, including identifying conflicts in theories about gossip and ritual, comparing hypotheses relating population size and morphological complexity, and an author relation network.
... In tutta questa discussione vanno tenuti distinti due filoni di ricerca piuttosto diversi: da una parte i lavori, spesso di ispirazione antropologica, volti ad indagare quanto il contesto culturale possa influire sulla lingua in termini di categorizzazioni lessicali o semantiche, dall'altra gli studi (ripresi ad esempio da Trudgill 2011) che indagano la correlazione fra fattori extralinguistici e categorie linguistiche. In questo ambito non mancano gli approcci correlativi e quantitativo-probabilistici: si veda a questo proposito il numero monografico di Linguistic Typology 15/2 (2011) dedicato al dibattito sulla correlazione fra inventari fonologici e fattori demografici e Nettle (2012) per una rassegna di alcuni contributi recenti in questo ambito. Un classico sul tema è naturalmente Nichols (1992). ...
Full-text available
Chapter
... Differences in response length due to linguistic reasons. The difference in response length across countries is partially driven by the fact that languages, due to inherent grammatical features, differ in the number of words that are necessary to express the same opinion (Nettle, 2012). When looking at original texts and their translations, these differences become obvious and translate into what we call text expansion: For instance, a study by Wells et al. (2010) reported that the Spanish-language versions of their questionnaires in the United States were on average 15% longer than the English source questionnaires. ...
Article
Methodological studies usually gauge response quality in narrative open-ended questions with the proportion of nonresponse, response length, response time, and number of themes mentioned by respondents. However, not all of these indicators may be comparable and appropriate for evaluating open-ended questions in a cross-national context. This study assesses the cross-national appropriateness of these indicators and their potential bias. For the analysis, we use data from two web surveys conducted in May 2014 with 2,685 respondents and in June 2014 with 2,689 respondents and compare responses from Germany, Great Britain, the United States, Mexico, and Spain. We assess open-ended responses for a variety of topics (e.g., national identity, gender attitudes, and citizenship) with these indicators and evaluate whether they arrive at similar or contradictory conclusions about response quality. We find that all indicators are potentially biased in a cross-national context due to linguistic and cultural reasons and that the bias differs in prevalence across topics. Therefore, we recommend using multiple indicators as well as items covering a range of topics when evaluating response quality in open-ended questions across countries.
... Ever since Trudgill's (2011) book, this approach has been known under the label sociolinguistic typology. Many publications have appeared over the last couple of decades, which provide both negative and positive evidence for adaptive responses of language structures to the sociolinguistic environment (for a recent overview see Nettle 2012). Particularly debated is the question of how to identify appropriate variables, both at the linguistic and extra-linguistic level, for testing hypotheses on linguistic adaptation. ...
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One of the fundamental questions about human language is whether all languages are equally complex. To answer this long-standing question, we conduct a large scale quantitative cross-linguistic analysis of written language by training a language model on more than 6,500 different documents as represented in 41 multilingual text collections consisting of ~3.5 billion words or ~9.0 billion characters and covering 2,069 different languages that are spoken as a native language by more than 90% of the world population or ~46% of all languages that have a standardized written representation. Statistically inferring the entropy of each language-model as an index of (un)predictability/complexity allows us to refute the equi-complexity hypothesis, but also unveils a previously undocumented complexity-efficiency trade-off: high entropy languages are information-theoretically more efficient because they tend to need fewer symbols to encode messages. Our findings additionally contribute to debates about language evolution/diversity by showing that this trade-off is partly shaped by the social environment in which languages are being used.
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William O’Grady is a professor in the Department of Linguistics at the University of Hawai‘i at Mānoa. He is well known for his writings on syntactic theory and language acquisition, as well as for his work on Korean and Jejueo. A major theme in O’Grady’s research is his commitment to emergentism, the idea that language is a complex system whose properties derive from the interaction of more basic factors and forces, especially processing pressures.O’Grady is the author of several books and numerous journal articles. His books include How Children Learn Language, Syntactic Carpentry, and Jejueo: The Language of Korea’s Jeju Island. He is the co-editor (with Brian MacWhinney) of The Handbook of Language Emergence and the co-editor (with John Archibald) of a widely used textbook, Contemporary Linguistics Analysis, now in its ninth edition.
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Heritage languages are often discussed in terms of their (reduced) complexity, but few attempts have been made to objectively measure the complexity of heritage languages. Here we explore various approaches to the investigation of language complexity, discussing three broad areas of inquiry: (i) attempts to objectively measure grammatical complexity, (ii) the potential role of socio-demographic factors in explaining variability in complexity, and (iii) considerations beyond grammatical complexity, which include the various aspects of complexity invoked when language is used for the purpose of communication. At each point, we highlight potential wisdom to be drawn from existing studies of heritage languages, which help to inform hypotheses for future study. The upshot is that complexity in heritage languages is itself a complex phenomenon – an observation that calls into question traditional characterizations of heritage languages in terms of an overall decrease in complexity.
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Both the music and social bonding (MSB) hypothesis and the music as a credible signal hypothesis emerge as solid views of how human music and human musicality might have evolved. Nonetheless, both views could be improved (and tested in better ways) with the consideration of the way in which human language(s) might have evolved under the effects of our self-domestication.
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Psychological research in small-scale societies is crucial for what it stands to tell us about human psychological diversity. However, people in these communities, typically Indigenous communities in the global South, have been underrepresented and sometimes misrepresented in psychological research. Here I discuss the promises and pitfalls of psychological research in these communities, reviewing why they have been of interest to social scientists and how cross-cultural comparisons have been used to test psychological hypotheses. I consider factors that may be undertheorized in our research, such as political and economic marginalization, and how these might influence our data and conclusions. I argue that more just and accurate representation of people from small-scale communities around the world will provide us with a fuller picture of human psychological similarity and diversity, and it will help us to better understand how this diversity is shaped by historical and social processes. Expected final online publication date for the Annual Review of Psychology, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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We study a set of algorithms to discover the community structure of networks for languages from the Americas. Our experiments are based on a parallel corpus which allows us to represent each language as a co-occurrence network. Four methods to calculate network modularity, as a measure of the quality of community structure, were used. We studied several aspects of the community structure of co-occurrence networks. First, we were able to construct the map of modularity variations across languages from the Americas. With this, we separated large groups of languages into low- and high-modularity families. We suggested also a strong influence of functional words on low-modularity languages. Finally, we found a strong relationship between word entropy values and modularity. Our approach is thus a simple network-based contribution to face data scarcity of languages which are in danger of disappearing.
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Culture, defined as socially transmitted information and behaviors that are shared in groups and persist over time, is increasingly accepted to occur across a wide range of taxa and behavioral domains. While persistent, cultural traits are not necessarily static, and their distribution can change in frequency and type in response to selective pressures, analogous to that of genetic alleles. This has lead to the treatment of culture as an evolutionary process, with cultural evolutionary theory arguing that culture exhibits the three fundamental components of Darwinian evolution: variation, competition, and inheritance. Selection for more efficient behaviors over alternatives is a crucial component of cumulative cultural evolution, yet our understanding of how and when such cultural selection occurs in non-human animals is limited. We performed a cultural diffusion experiment using 18 captive populations of wild-caught great tits (Parus major) to ask whether more efficient foraging traditions are selected for, and whether this process is affected by a fundamental demographic process—population turnover. Our results showed that gradual replacement of individuals with naive immigrants greatly increased the probability that a more efficient behavior invaded a population’s cultural repertoire and out-competed an established inefficient behavior. Fine-scale, automated behavioral tracking revealed that turnover did not increase innovation rates, but instead acted on adoption rates, as immigrants disproportionately sampled novel, efficient behaviors relative to available social information. These results provide strong evidence for cultural selection for efficiency in animals, and highlight the mechanism that links population turnover to this process.
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There is an ongoing debate as to whether linguistic structure is influenced by demographic factors. Relationships between these two domains have been investigated on the phonological, morphological and lexical level, mainly drawing on synchronic data and comparative methodology. In this exploratory study, by contrast, we focus on the lesser recognized level of phonotactics, and adopt a methodologically orthogonal approach. We investigate the diachronic development of a single lineage, namely English, and compare it with concomitant developments of the demography of the English-speaking population. In addition to linguistic and demographic factors, we also derive characteristics of the underlying speaker network (network diameter; clustering coefficient). Empirically, we focus on the system of English consonant clusters, which we argue to be particularly sensitive to linguistic change so that effects of demography are expected to be more clearly visible than in more robust linguistic subsystems (e.g. phoneme inventory; morphology). By employing time-series clustering, it is shown that the trajectory of phonotactic diversity in English coda clusters most closely matches that of covariates related with density and heterogeneity of the speaker population. Linguistic covariates are less closely related. We conclude that heterogeneity of the linguistic input and the number of informants a learner is exposed to are relevant factors in the evolution of phonotactic diversity.
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Construction grammar is an approach to language that posits that units and structures in language can be exhaustively described as pairings between form and meaning. These pairings are called constructions and can have different degrees of abstraction, i.e. they span the entire range from very concrete ( armadillo, avocado ) to very abstract constructions such as the ditransitive construction ( I gave her a book ). This approach has been applied to a wide variety of different areas of research in linguistics, such as how new constructions emerge and change historically. It has also been applied to investigate the evolutionary emergence of modern fully fledged language, i.e. the question of how systems of constructions can arise out of prelinguistic communication. In this paper, we review the contribution of usage-based construction grammar approaches to language change and language evolution to the questions of (i) the structure and nature of prehistoric languages and (ii) how constructions in prehistoric languages emerged out of non-linguistic or protolinguistic communication. In particular, we discuss the possibilities of using constructions as the main unit of analysis both in reconstructing predecessors of existing languages (protolanguages) and in formulating theories of how a potential predecessor of human language in general (protolanguage) must have looked like. This article is part of the theme issue ‘Reconstructing prehistoric languages’.
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Selection for more efficient socially learned behaviors over alternatives is crucial for cumulative cultural evolution, yet our understanding of such cultural selection in animals is limited. We performed a cultural diffusion experiment using 18 populations of wild-caught great tits Parus major to ask whether more efficient foraging traditions are selected for, and whether this process is affected by turnover. We show that gradual replacement of individuals greatly increases the probability that a more efficient behavior will invade a population's cultural repertoire, out-competing an established inefficient behavior. Turnover does not increase innovation rates, but instead increases adoption rates, as immigrants are more susceptible to novel, efficient behaviors. An agent based model further supported our results by demonstrating that this effect holds across populations of different types of learners. Altogether, these results provide strong evidence for cultural selection for efficiency in animals, and highlight the importance of population turnover for this process.
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Selection for more efficient socially learned behaviors over alternatives is crucial for cumulative cultural evolution, yet our understanding of such cultural selection in animals is limited. We performed a cultural diffusion experiment using 18 populations of wild-caught great tits Parus major to ask whether more efficient foraging traditions are selected for, and whether this process is affected by turnover. We show that gradual replacement of individuals greatly increases the probability that a more efficient behavior will invade a population's cultural repertoire, out-competing an established inefficient behavior. Turnover does not increase innovation rates, but instead increases adoption rates, as immigrants are more susceptible to novel, efficient behaviors. An agent based model further supported our results by demonstrating that this effect holds across populations of different types of learners. Altogether, these results provide strong evidence for cultural selection for efficiency in animals, and highlight the importance of population turnover for this process.
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We propose that languages (and seemingly our language capabilities) evolved gradually as a result of being engaged in an active feedback loop with human self-domestication. Our proposal primarily builds on the management of aggression: it ties early stages of the evolution of languages with the taming of reactive aggression, whereas it ties late stages with the rise of proactive aggression. Overall, we posit a four-stage model, from simple (even single-word) utterances (Stage One), to simple two-slot grammars (Stage Two), to languages optimized for in-group communication (Stage Three), to languages better suited for communicating non-shared knowledge to strangers (Stage Four).
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Studies of artificial language learning provide insight into how learning biases and iterated learning may shape natural languages. Prior work has looked at how learners deal with unpredictable variation and how a language changes across multiple generations of learners. The present study combines these features, exploring how word order variation is preserved or regularized over generations. We investigate how these processes are affected by (1) learning biases, (2) the size of the language community, and (3) the amount of input provided. Our results show that when the input comes from a single speaker, adult learners frequency match, reproducing the variability in the input across three generations. However, when the same amount of input is distributed across multiple speakers, frequency matching breaks down. When regularization occurs, there is a strong bias for SOV word order (relative to OSV and VSO). Finally, when the amount of input provided by multiple speakers is increased, learners are able to frequency match. These results demonstrate that both population size and the amount of input per speaker each play a role in language convergence.
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Cross-cultural comparison is a common method of testing hypotheses regarding the co-evolution of elements of cultures or of the adaptiveness of a cultural practice to some aspect of the environment. It has long been recognized, however, that cultures are not independent but rather may share many cultural elements by virtue of common ancestry and proximity. Attempts to address this issue, known as Galton's problem, range from statistically removing confounding variables to using a standard sample of ''independent cultures.'' We show here that when testing any hypothesis of co-evolution one should not attempt to identify independent cultures or to create them statistically. Rather, cross-cultural comparative studies must be based upon the identification of independent events of cultural change. Once this principle is applied, it becomes apparent that it is in fact groups of closely related cultures that are potentially the most informative for testing cross-cultural hypotheses. Constructing phylogenies of cultures and placing upon them independent instances of cultural elements' arising or changing is an essential part of this task. Reprinted in (Linquist, S, ed) The Evolution of Culture. The International Library of Essays on Evolutionary Thought. Farnham, UK: Ashgate Publishing (2010).
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Analysis of a linguistic atlas reveals an ecological gradient in the diversity of languages in West Africa. As one moves south from arid into lusher ecoclimatic zones, the average size of ethnolinguistic groups decreases. Various factors are considered which may have contributed to this distribution. I argue that the ethnolinguistic map is primarily a reflection of the systems of generalized exchange and mutual dependence into which people enter. It is hypothesized that such social networks function to reduce subsistence risk due to variations in the food supply. If this hypothesis is correct, the average size of ethnolinguistic groups should be inversely proportional to the degree of ecological variability they face. This prediction is tested and found to hold strongly for a large part of West Africa. There is also limited evidence of a correlation between linguistic diversity and topography. It is concluded that ecological risk has been a key historical force in West Africa and that the ethnolinguistic mosaic can be used as a valuable “fossil record” of people's adaptive social and economic strategies.
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There is a challenging issue for linguistic typology which involves the relationships which might exist between societal type and aspects of linguistic structure. Linguistic-typological studies have provided us with insights into the range of structures available in human languages, but we do not yet have explanations for why, of all the possible structures available, particular languages select particular structures and not others. A legitimate sociolinguistic viewpoint would be that some social explanations may be available. The sociolinguistic factors suggested as being relevant are language contact versus isolation, and community size and network structure. This paper deals with this thesis from the point of view of Austronesian phonology, with particular reference to Polynesian phoneme inventories.
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Modern women's reproductive lives vary considerably, in a patterned fashion. Although cultural factors are important, across societies—even across species— there exist strong patterns predicted by life history theory. For example, the shorter life expectancy e0 is at birth, the earlier it pays in biological terms to reproduce. Few factors analyzed in women's life patterns in more than 170 nations influence the divergence. Studies on other species assume that (a) the variation is species specific and (b) the conditions are at equilibrium; the relationship between life expectancy and age at first birth is strong, but varies across populations, and is frequently not at equilibrium. Human patterns, like those of other species, may have ecological or life history underpinnings. The answers we find may have policy implications for women's lives and fertility.
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The number of different species found in a given area of the Earth increases from the poles towards the equator for a wide range of terrestrial and marine organisms. A similar but opposite latitudinal gradient is also generally found in the size of the geographic range over which a species is found: range sizes are larger in more northern latitudes becoming smaller in the south, a phenomenon known as Rapaport's rule. Here we show that the density of human language-cultural groups in North America, at the time of contact by colonizing Europeans, also followed a strong latitudinal gradient qualitatively similar to that found in North American mammals. Six times, or more, different languages were spoken in a given area in southern latitudes, compared to the density of language groups nearer to the poles. In addition, the amount of territory over which the speakers of a given language were found increases with latitude: linguistic-cultural groups conform to Rapaport's rule. Finally, based upon a categorization of North America into 23 distinct major habitat types, we find greater linguistic diversity in areas of greater habitat diversity, independently of latitude. `Linguistic ecology', or the examination of ecological factors associated with diversity in the number of linguistic groups, may shed new light on some features of cultural and linguistic evolution.
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This paper contrasts two influential theoretical accounts of language change and evolution - Iterated Learning and Social Coordination. The contrast is based on an experiment that compares drawings produced with Garrod et al.'s (2007) 'pictionary' task with those produced in an Iterated Learning version of the same task. The main finding is that Iterated Learning does not lead to the systematic simplification and increased symbolicity of graphical signs produced in the standard interactive version of the task. A second finding is that Iterated Learning leads to less conceptual and structural alignment between participants than observed for those in the interactive condition. The paper concludes with a comparison of the two accounts in relation to how each promotes signs that are efficient, systematic and learnable.
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In this chapter I define and then compare social complexity to vocal complexity in bats. Bats provide an interesting comparison to primates because these two mammalian orders do not have a recent common ancestor. All species in one suborder, the Microchiroptera, rely on the echoes of high-frequency vocalizations to perceive their world. Perhaps as a consequence, many bat species exhibit a rich repertoire of communication vocalizations. Bats also display a wide variety of social organizations that rival primates both in diversity and complexity. Although my goal in this chapter is to provide an independent test of the Machiavellian intelligence hypothesis, I also consider alternative scenarios that could give rise to associations among social complexity, relative neocortex volume, and vocal complexity in bats, as well as suggest promising areas for further study. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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Previous literature has reported a positive correlation between phoneme inventory sizes and population sizes for languages, indicating that larger languages tend to make more phonological distinctions, and claims have also been made that average word length and phoneme inventory sizes are negatively correlated. Yet another relevant variable is geog-raphy, since the spatial propinquity of languages influences the similarity of their overall typological profile; moreover, specific historical events affecting language distributions, such as migrations or the development of certain cultural advantages, are usually also anchored geographically. In this paper we replicate previous findings on a substantially larger set of data drawn from comparative wordlists in the database of the Automated Similarity Judgment Program (ASJP) and discuss the relationships among the three variables mentioned in the title of the paper as well the influence of geography, including the idea that phonemic diversity across the world's languages provides evidence for an out-of-Africa model of the expansion of languages.
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The computer simulation of language change in a finite, structured population which was presented in an earlier paper (‘Using Social Impact Theory to simulate language change’, Lingua 108, 95–117, 1999), is here extended to speech communities of different sizes. On the basis of the results it is proposed 1.(a) that language change may be faster in small communities;2.(b) that linguistic borrowing is one sense more likely in small communities; and3.(c) that the evolution of linguistically marked structures is more likely in small communities. It is argued that these three generalisations could be used to make sense of the different patterns of linguistic diversity observed in the Old and New Worlds, and the distribution of marked word orders in the world's languages.
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The six and a half thousand languages spoken by humankind are very unevenly distributed across the globe. Language diversity generally increases as one moves from the poles toward the equator and is very low in arid environments. Two belts of extremely high language diversity can be identified. One runs through West and Central Africa, while the other covers South and South-East Asia and the Pacific. Most of the world's languages are found in these two areas. This paper attempts to explain aspects of the global distribution of language diversity. It is proposed that a key factor influencing it has been climatic variability. Where the climate allows continuous food production throughout the year, small groups of people can be reliably self-sufficient and so populations fragment into many small languages. Where the variability of the climate is greater, the size of social network necessary for reliable subsistence is larger, and so languages tend to be more widespread. A regression analysis relating the number of languages spoken in the major tropical countries to the variability of their climates is performed and the results support the hypothesis. The geographical patterning of languages has, however, begun to be destroyed by the spread of Eurasian diseases, Eurasian people, and the world economy.
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This paper presents a framework for simulating language change in social networks derived from Social Impact Theory. In this framework, the language learner samples the speech of individuals from right across his speech community, though he may weight their input differentially according to their social position. This conceptualisation is argued to be more realistic than that provided by other models. Computer simulations are used to investigate the effects on language change of different social structures and biases in language acquisition. From the results of these simulations, it is argued that the fundamental engine driving language change is the combination of inherent variation in language acquisition and differences between individuals in local social influence. Functional biases attaching to different linguistic variants influence the direction of language change.
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How to measure morphological complexity is itself an issue of some complexity. (Nichols, 1992)This article develops an information‐theoretic and functionally motivated method of measuring “linguistic complexity”; from corpora that can in theory be applied to any definable substructure. This method is further extended into a way of objectively and numerically measuring the morphological complexity of a given language sample, avoiding the typical difficulties of focusing on only a few unrepresentative types of constructions. By selectively altering the morphological information present in a sample, the complexity can be measured as the change in overall informativeness of a text. This claim has been tested in a small‐scale cross‐linguistic experiment; the results agree well with both intuitions and existing measurements.
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Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. Here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder-effect model of expansion from an inferred origin in Africa. This result, which is not explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.
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Languages vary widely but not without limit. The central goal of linguistics is to describe the diversity of human languages and explain the constraints on that diversity. Generative linguists following Chomsky have claimed that linguistic diversity must be constrained by innate parameters that are set as a child learns a language. In contrast, other linguists following Greenberg have claimed that there are statistical tendencies for co-occurrence of traits reflecting universal systems biases, rather than absolute constraints or parametric variation. Here we use computational phylogenetic methods to address the nature of constraints on linguistic diversity in an evolutionary framework. First, contrary to the generative account of parameter setting, we show that the evolution of only a few word-order features of languages are strongly correlated. Second, contrary to the Greenbergian generalizations, we show that most observed functional dependencies between traits are lineage-specific rather than universal tendencies. These findings support the view that-at least with respect to word order-cultural evolution is the primary factor that determines linguistic structure, with the current state of a linguistic system shaping and constraining future states.
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From an ultimate perspective, the age of onset of female reproduction should be sensitive to variation in mortality rates, and variation in the productivity of non-reproductive activities. In accordance with this prediction, most of the cross-national variation in women's age at first birth can be explained by differences in female life expectancies and incomes. The within-country variation in England shows a similar pattern: women have children younger in neighbourhoods where the expectation of healthy life is shorter and incomes are lower. I consider the proximate mechanisms likely to be involved in producing locally appropriate reproductive decisions. There is evidence suggesting that developmental induction, social learning and contextual evocation may all play a role.
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There are approximately 7000 languages spoken in the world today. This diversity reflects the legacy of thousands of years of cultural evolution. How far back we can trace this history depends largely on the rate at which the different components of language evolve. Rates of lexical evolution are widely thought to impose an upper limit of 6000-10,000 years on reliably identifying language relationships. In contrast, it has been argued that certain structural elements of language are much more stable. Just as biologists use highly conserved genes to uncover the deepest branches in the tree of life, highly stable linguistic features hold the promise of identifying deep relationships between the world's languages. Here, we present the first global network of languages based on this typological information. We evaluate the relative evolutionary rates of both typological and lexical features in the Austronesian and Indo-European language families. The first indications are that typological features evolve at similar rates to basic vocabulary but their evolution is substantially less tree-like. Our results suggest that, while rates of vocabulary change are correlated between the two language families, the rates of evolution of typological features and structural subtypes show no consistent relationship across families.
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Languages differ greatly both in their syntactic and morphological systems and in the social environments in which they exist. We challenge the view that language grammars are unrelated to social environments in which they are learned and used. We conducted a statistical analysis of >2,000 languages using a combination of demographic sources and the World Atlas of Language Structures--a database of structural language properties. We found strong relationships between linguistic factors related to morphological complexity, and demographic/socio-historical factors such as the number of language users, geographic spread, and degree of language contact. The analyses suggest that languages spoken by large groups have simpler inflectional morphology than languages spoken by smaller groups as measured on a variety of factors such as case systems and complexity of conjugations. Additionally, languages spoken by large groups are much more likely to use lexical strategies in place of inflectional morphology to encode evidentiality, negation, aspect, and possession. Our findings indicate that just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. As adults learn a language, features that are difficult for them to acquire, are less likely to be passed on to subsequent learners. Languages used for communication in large groups that include adult learners appear to have been subjected to such selection. Conversely, the morphological complexity common to languages used in small groups increases redundancy which may facilitate language learning by infants. We hypothesize that language structures are subjected to different evolutionary pressures in different social environments. Just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. The proposed Linguistic Niche Hypothesis has implications for answering the broad question of why languages differ in the way they do and makes empirical predictions regarding language acquisition capacities of children versus adults.
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Previous empirical studies of population size and language change have produced equivocal results. We therefore address the question with a new set of lexical data from nearly one-half of the world's languages. We first show that relative population sizes of modern languages can be extrapolated to ancestral languages, albeit with diminishing accuracy, up to several thousand years into the past. We then test for an effect of population against the null hypothesis that the ultrametric inequality is satisfied by lexical distances among triples of related languages. The test shows mainly negligible effects of population, the exception being an apparently faster rate of change in the larger of two closely related variants. A possible explanation for the exception may be the influence on emerging standard (or cross-regional) variants from speakers who shift from different dialects to the standard. Our results strongly indicate that the sizes of speaker populations do not in and of themselves determine rates of language change. Comparison of this empirical finding with previously published computer simulations suggests that the most plausible model for language change is one in which changes propagate on a local level in a type of network in which the individuals have different degrees of connectivity.
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Talk of linguistic universals has given cognitive scientists the impression that languages are all built to a common pattern. In fact, there are vanishingly few universals of language in the direct sense that all languages exhibit them. Instead, diversity can be found at almost every level of linguistic organization. This fundamentally changes the object of enquiry from a cognitive science perspective. This target article summarizes decades of cross-linguistic work by typologists and descriptive linguists, showing just how few and unprofound the universal characteristics of language are, once we honestly confront the diversity offered to us by the world's 6,000 to 8,000 languages. After surveying the various uses of “universal,” we illustrate the ways languages vary radically in sound, meaning, and syntactic organization, and then we examine in more detail the core grammatical machinery of recursion, constituency, and grammatical relations. Although there are significant recurrent patterns in organization, these are better explained as stable engineering solutions satisfying multiple design constraints, reflecting both cultural-historical factors and the constraints of human cognition. Linguistic diversity then becomes the crucial datum for cognitive science: we are the only species with a communication system that is fundamentally variable at all levels. Recognizing the true extent of structural diversity in human language opens up exciting new research directions for cognitive scientists, offering thousands of different natural experiments given by different languages, with new opportunities for dialogue with biological paradigms concerned with change and diversity, and confronting us with the extraordinary plasticity of the highest human skills.
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One of the oldest concerns of social science has been to explain the differrent levels of wealth of different nations. This problem, originally posed by Adam Smith in a mainly European context, has become increasingly salient again as debates over the prospects for economic growth in the developing world have come to the fore. Many researchers thus have become interested in cross-national studies of the geographical and societal correlates of economic development. In this article, then, I set out to directly retest the Fishman-Pool hypothesis, using data on the level of economic activity rather than the rate of growth over some short period of time, and without including any factors that may themselves be consequences of fragmentation. First I attempt to reproduce the original correlation from Pool's study with a more comprehensive and accurate data set and to control for several possible intervening variables. I then consider the results, their causal interpretation, and their implications for economic development and language shift.
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We introduce an experimental paradigm for studying the cumulative cultural evolution of language. In doing so we provide the first experimental validation for the idea that cultural transmission can lead to the appearance of design without a designer. Our experiments involve the iterated learning of artificial languages by human participants. We show that languages transmitted culturally evolve in such a way as to maximize their own transmissibility: over time, the languages in our experiments become easier to learn and increasingly structured. Furthermore, this structure emerges purely as a consequence of the transmission of language over generations, without any intentional design on the part of individual language learners. Previous computational and mathematical models suggest that iterated learning provides an explanation for the structure of human language and link particular aspects of linguistic structure with particular constraints acting on language during its transmission. The experimental work presented here shows that the predictions of these models, and models of cultural evolution more generally, can be tested in the laboratory. • cultural transmission • iterated learning • language evolution
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Understanding the rules that link communication and social behaviour is an essential prerequisite for discerning how a communication system as complex as human language might have evolved. The comparative method offers a powerful tool for investigating the nature of these rules, since it provides a means to examine relationships between changes in communication abilities and changes in key aspects of social behaviour over evolutionary time. Here we present empirical evidence from phylogenetically controlled analyses indicating that evolutionary increases in the size of the vocal repertoire among non-human primate species were associated with increases in both group size and time spent grooming (our measure of extent of social bonding).
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Foreigners often say that the English language is "easy". A language like Spanish is challenging in its variety of verb endings and gender for nouns, whereas English is more straightforward. But linguists generally deny claims that certain languages are 'easier' than others, since it is assumed that all languages are complex to the same degree. For example, they will point to English's use of the word "do" - Do you know French? This usage is counter-intuitive and difficult for non-native speakers. This book agrees that all languages are complex, but questions whether or not they are all equally complex. The topic of complexity has become an area of great debate in recent years, particularly in creole studies, historical linguistics, and language contact. This book describes when languages came into contact (when French-speakers ruled the English for a few centuries, or the Vikings invaded England), a large number of speakers are forced to learn a new language quickly and thus came up with a simplified version, a pidgin. When this ultimately turns into a "real" language, a creole, the result is still simpler and less complex than a "non-interrupted" language that has been around for a long time. This book makes the case that this kind of simplification happens by degrees, and criticizes linguists who are reluctant to say that, for example, English is simpler than Spanish for socio-historical reasons. It analyzes how various languages that seem simple but are not creoles, actually are simpler than they would be if they had not been broken down by large numbers of adult learners. In addition to English, the book looks at Mandarin Chinese, Persian, Malay, and some Arabic varieties.
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Functional theories of language structure predict that as the number of contrastive segments in a language increases, the average length of a word will decrease. This relationship is found to hold for a sample of ten languages, and to fit the synergetic model Y=aXb. The average length of a word is approximately 7±2 segments. This corresponds to the proposed capacity of working memory.
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Previous research has shown that speakers in warm-climate languages make use of relatively more vowels, and speakers in cold-climate languages relatively more consonants. The high sonority (audibility) of the vowel, and its adaptive value under certain conditions, have been invoked to account for its greater frequency in warmer climates. We show here, however, that the above generalization is over-broad, and that sound classes vary across climate zones in complex ways. One new finding is that speakers in warm-climate languages make more use of the so-called “sonorant” consonants, that is, consonants with some of the qualities of vowels. We offer a provisional framework that continues to find value in the concept of sonority and its relation to climate, but attempts to incorporate the new results and provide a more comprehensive explanation.
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Previous cross-cultural research by Robert Munroe and colleagues has linked two features of language to warm climates—a higher proportion of consonant-vowel syllables and a higher proportion of sonorous (more audible) sounds. The underlying theory is that people in warmer climates communicate at a distance more often than people in colder climates, and it is adaptive to use syllables and sounds that are more easily heard and recognized at a distance. However, there is considerable variability in warm as opposed to cold climates, which needs to be explained. In the present research report, we show that additional factors increase the predictability of sonority. We find that more specific features of the environment—such as type of plant cover and degree of mountainous terrain—help to predict sonority. And, consistent with previous research on folk-song style, measures of sexual restrictiveness also predict low sonority.
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In the current resurgence of interest in the biological basis of animal behavior and social organization, the ideas and questions pursued by Charles Darwin remain fresh and insightful. This is especially true of The Descent of Man and Selection in Relation to Sex, Darwin's second most important work. This edition is a facsimile reprint of the first printing of the first edition (1871), not previously available in paperback. The work is divided into two parts. Part One marshals behavioral and morphological evidence to argue that humans evolved from other animals. Darwin shoes that human mental and emotional capacities, far from making human beings unique, are evidence of an animal origin and evolutionary development. Part Two is an extended discussion of the differences between the sexes of many species and how they arose as a result of selection. Here Darwin lays the foundation for much contemporary research by arguing that many characteristics of animals have evolved not in response to the selective pressures exerted by their physical and biological environment, but rather to confer an advantage in sexual competition. These two themes are drawn together in two final chapters on the role of sexual selection in humans. In their Introduction, Professors Bonner and May discuss the place of The Descent in its own time and relation to current work in biology and other disciplines.
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Le phenomene de parente areale peut s'etendre jusqu'a un continent, ne peut donc etre neglige au profit d'une typologie " preferentielle " des langues du monde. L'auteur propose une methode d'echantillonnage
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It is often stated that all languages are equal in terms of complexity. This paper introduces a metric of complexity, determined by degree of overt signalling of various phonetic, morphological, syntactic, and semantic distinctions beyond communicative necessity. By this metric, a subset of creole languages display less overall grammatical complexity than older languages, by virtue of the fact that they were born as pidgins, and thus stripped of almost all features unnecessary to communication, and since then have not existed as natural languages for a long enough time for diachronic drift to create the weight of "ornament" that encrusts older languages. It is demonstrated that this complexity differential remains robust even when creoles are compared with older languages lacking inflection, contra claims by theoretical syntacticians that the typology of creoles is largely a manifestation of parameter settings resulting from low inflection. The overall aim is to bolster a general paradigm arguing that creole languages are delineable synchronically as well as sociohistorically.
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This short report investigates the relationship between population size and phoneme inventory size, and finds a surprisingly robust correlation between the two. The more speakers a language has, the bigger its phoneme inventory is likely to be. We show that this holds for both vowel inventories and consonant inventories. It is not an artifact of language family.
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Recent comparative studies point to the importance of mortality schedules as determinants in the evolution of life-history characteristics. In this paper, we compare patterns of mortality from natural populations of mammals with a variety of life histories. We find that, after removing the effects of body weight, mortality is the best predictor of variation in life-history traits. Mammals with high levels of natural mortality tend to mature early and give birth to small offspring in large litters after a short gestation, before and after body size effects are factored out. We examine the way in which life-history traits relate to juvenile mortality versus adult mortality and find that juvenile mortality is more highly correlated with life-history traits than is adult mortality. We discuss the necessity of distinguishing between extrinsic sources of mortality (e.g. predation) and mortality caused by intrinsic sources (e.g. costs of reproduction), and the role that ecology might play in the evolution of patterns of mortality and fecundity. We conclude that these results must be explained not simply in the light of the demographic necessity of balancing mortality and fecundity, but as a result of age-specific costs and benefits of reproduction and parental investment. Detailed comparative studies of mortality patterns in natural populations of mammals offer a promising avenue towards understanding the evolution of life-history strategies.
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We explore the proposal that the linguistic forms and structures employed by our earliest language-using ancestors might have been significantly different from those observed in the languages we are most familiar with today, not because of a biological difference between them and us, but because the communicative context in which they operated was fundamentally different from that of most modern humans. Languages that are used predominantly for esoteric (intra-group) communication tend to have features that are semantically and grammatically ‘complex’, while those used also (or even exclusively) for exoteric (inter-group) communication become ‘simplified’ towards rule-based regularity and semantic transparency. Drawing on a range of contemporary data, we propose a psycholinguistic explanation for why esotericity would promote such complexity, and argue that this is the natural default setting for human language. This being so, it should be taken into account when modelling the evolution of language, for some of the features that are normally viewed as fundamental – including the notion of fully developed underlying rule-based systematicity – may, in fact, be cultural add-ons.
Article
Synergetic models of language structure predict that the length of a word will depend upon various parameters such as its frequency and the number of phonemes in the language. This prediction has been used to explain word length differences within languages, but less often to explain the differences between languages. Here I show that average word length across 12 West African languages is related to the size of the phonological inventory. This is an apparent example of the adaptation of language structure to the efficient communication of information. The hypothesised mechanism by which the relationship evolves are outlined.
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A combination of archeological and ethnohistorical evidence indicates that, over an approximately 8,000-year period,from the beginning of the Holocene until European explorers began arriving in the eighteenth century, the societies of Tasmania lost a series of valuable skills and technologies. These likely included bone tools, cold-weather clothing, hafted tools, nets, fishing spears, barbed spears, spear-throwers, and boomerangs. To address this puzzle, and the more general question of how human cognition and social interaction can generate both adaptive cultural evolution and maladaptive losses of cul-turally acquired skills, this paper constructs a formal model of cultural evolution rooted in the cognitive details of human social learning and inference. The analytical results specify the conditions for differing rates of adaptive cultural evolution. and reveal regimes that it-ill produce maladaptive losses of particular kinds of skills and related technologies. More specifically. the results suggest that the relatively sudden reduction in the effective population size (the size of the interact-ing pool of social learners) that occurred with the rising ocean levels at the end of the last glacial epoch, which cut Tas-mania off from the rest of Australia for the ensuing tea millennia, could have initiated a cultural evolutionary process that (1) kept stable or even improved relatively simple technological skills, and (2) produced an increasing deterioration of more complex skills leading to the complete disappearance of some technologies and practices. This pattern is consistent with the empirical record in Tasmania. Beyond this case, I speculate on the applicability of the model to understanding the vari-ability in rates of adaptive cultural evolution.
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Recent research suggests that language evolution is a process of cultural change, in which linguistic structures are shaped through repeated cycles of learning and use by domain-general mechanisms. This paper draws out the implications of this viewpoint for understanding the problem of language acquisition, which is cast in a new, and much more tractable, form. In essence, the child faces a problem of induction, where the objective is to coordinate with others (C-induction), rather than to model the structure of the natural world (N-induction). We argue that, of the two, C-induction is dramatically easier. More broadly, we argue that understanding the acquisition of any cultural form, whether linguistic or otherwise, during development, requires considering the corresponding question of how that cultural form arose through processes of cultural evolution. This perspective helps resolve the "logical" problem of language acquisition and has far-reaching implications for evolutionary psychology.
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The historical origins of natural language cannot be observed directly. We can, however, study systems that support language and we can also develop models that explore the plausibility of different hypotheses about how language emerged. More recently, evolutionary linguists have begun to conduct language evolution experiments in the laboratory, where the emergence of new languages used by human participants can be observed directly. This enables researchers to study both the cognitive capacities necessary for language and the ways in which languages themselves emerge. One theme that runs through this work is how individual-level behaviours result in population-level linguistic phenomena. A central challenge for the future will be to explore how different forms of information transmission affect this process.
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In this ground-breaking book, Johanna Nichols proposes means of describing, comparing, and interpreting linguistic diversity, both genetic and structural, providing the foundations for a theory of diversity based upon population science. This book will interest linguists, archaeologists, and population specialists. "An awe-inspiring book, unequalled in scope, originality, and the range of language data considered."—Anna Siewierska, Linguistics "Fascinating. . . . A brilliant pioneering study."—Journal of Indo-European Studies "A superbly reasoned book."—John A. C. Greppin, Times Literary Supplement
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Human societies are remarkably variable in terms of their size, complexity, social structure, marriage systems and norms. This diversity has sometimes been raised as an obstacle to taking an evolutionary approach to human behaviour. However, a substantial proportion of the variation between human societies might represent local adaptation to ecological conditions and would thus be very much amenable to evolutionary explanation. I review recent studies correlating inter-population differences in humans with ecological factors, specifically pathogen prevalence. Many questions remain unanswered, such as whether we correctly understand the causal pathways and what the mechanisms producing local adaptation are, but the strength of correlations between social and ecological parameters is striking.
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While sociality has been hypothesized to drive the evolution of communicative complexity, the relationship remains to be formally tested. We derive a continuous measure of social complexity from demographic data and use this variable to explain variation in alarm repertoire size in ground-dwelling sciurid rodents (marmots, Marmota spp.; prairie dogs, Cynomys spp.; and ground squirrels, Spermophilus spp.). About 40% of the variation in alarm call repertoire size was explained by social complexity in the raw data set. To determine the degree to which this relationship may have been influenced by historical relationships between species, we used five different phylogenetic hypotheses to calculate phylogenetically independent contrasts. Less variation was significantly explained in contrast-based analyses, but a general positive relationship remained. Social complexity explained more variation in alarm call repertoire size in marmots, while sociality explained no variation in repertoire size in prairie dogs and no variation in phylogenetically based analyses of squirrels. In most cases, substantial variation remained unexplained by social complexity. We acknowledge that factors other than social complexity, per se, may contribute to the evolution of alarm call repertoire size in sciurid rodents, and we discuss alternative hypotheses. Our measure of social complexity could be used by other researchers to test explicit evolutionary hypotheses that involve social complexity.
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RECENT advances in molecular genetics have had a great deal of influence on evolutionary theory, and in particular, the neutral mutation-random drift hypothesis of molecular evolution1,2 has stimulated much interest. The concept of neutral mutant substitution in the population by random genetic drift can be extended to include random fixation of very slightly deleterious mutations which have more chance of being selected against than of being selected for3,4. If this class of mutant substitution is important, we can predict that the evolution is rapid in small populations or at the time of speciation5. Here I shall organize the observed facts which indicate that this class is in fact important.
Article
Two experiments were carried out to extend Logan et al.'s recent study [J. S. Logan, S. E. Lively, and D. B. Pisoni, J. Acoust. Soc. Am. 89, 874-886 (1991)] on training Japanese listeners to identify English /r/ and /l/. Subjects in experiment 1 were trained in an identification task with multiple talkers who produced English words containing the /r/-/l/ contrast in initial singleton, initial consonant clusters, and intervocalic positions. Moderate, but significant, increases in accuracy and decreases in response latency were observed between pretest and posttest and during training sessions. Subjects also generalized to new words produced by a familiar talker and novel words produced by an unfamiliar talker. In experiment 2, a new group of subjects was trained with tokens from a single talker who produced words containing the /r/-/l/ contrast in five phonetic environments. Although subjects improved during training and showed increases in pretest-posttest performance, they failed to generalize to tokens produced by a new talker. The results of the present experiments suggest that variability plays an important role in perceptual learning and robust category formation. During training, listeners develop talker-specific, context-dependent representations for new phonetic categories by selectively shifting attention toward the contrastive dimensions of the non-native phonetic categories. Phonotactic constraints in the native language, similarity of the new contrast to distinctions in the native language, and the distinctiveness of contrastive cues all appear to mediate category acquisition.