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Birth order and familial sentiment: Middleborns are different

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Abstract

Effects of birth order on several aspects of family relations and self-identity were examined in three studies. In Study 1, first and lastborn undergraduates were more likely than middleborns to refer to kinship in characterizing themselves. In Study 2, subjects were asked to whom they would turn under two scenarios of duress. First and lastborns were more likely to nominate parents, whereas middleborns were much more likely than other respondents to nominate siblings. In Study 3, analyses of historical archives and of an Internet questionnaire indicated that genealogical research attracts many more firstborns and many fewer middleborns than expected by chance. In all three studies, first and lastborns were much more likely than middleborns to nominate their mothers as the person to whom they felt closest. These substantial effects support Sulloway's claim that birth orders constitute significant family "niches," which differ with respect to the perceived dependability of parental investment and therefore also differ in the social orientations that they engender.

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... different from other birth orders. This argument is based on a lack of uniqueness and low parental investment attributed to the birth position of the middleborn, leading them to be coined as the "neglected birth order" (Kidwell, 1982;Salmon and Daly, 1998;Salmon et al., 2012). Firstborns have an advantage as, for a given period, they do not have to compete against another sibling for parental investment (Salmon, 2015;Salmon and Daly, 1998;Salmon et al., 2012). ...
... This argument is based on a lack of uniqueness and low parental investment attributed to the birth position of the middleborn, leading them to be coined as the "neglected birth order" (Kidwell, 1982;Salmon and Daly, 1998;Salmon et al., 2012). Firstborns have an advantage as, for a given period, they do not have to compete against another sibling for parental investment (Salmon, 2015;Salmon and Daly, 1998;Salmon et al., 2012). In addition, from an evolutionary perspective, it has been argued that parents could benefit from prioritising investment in the oldest child (see Lewis and Kreitzberg, 1979;Draper and Hames, 2000;Salmon and Daly, 1998;Sulloway, 1996). ...
... Firstborns have an advantage as, for a given period, they do not have to compete against another sibling for parental investment (Salmon, 2015;Salmon and Daly, 1998;Salmon et al., 2012). In addition, from an evolutionary perspective, it has been argued that parents could benefit from prioritising investment in the oldest child (see Lewis and Kreitzberg, 1979;Draper and Hames, 2000;Salmon and Daly, 1998;Sulloway, 1996). For example, firstborns, when they survive a period of heightened mortality during childhood, will have higher reproductive potential than other birth orders (Trivers, 1974). ...
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Middleborns have been argued to be the neglected birth order. The present study aimed to test whether the emotional closeness to parents, siblings or friends differed between middleborns and otherborns, across two different datasets. Using a between family design this study accounted for gender, nationality, educational attainment, age and sibship size via matching. We found no evidence to suggest that middleborns differ from otherborns in familial sentiment. The sign of closeness to friends was in the opposite direction than predicted, with middleborns being less close than other birth orders. The findings are discussed with reference to current literature on birth order and familial sentiment.
... Finally, three new and independent studies designed to test my own claims have confirmed the relationship between birth order and support for radical changes that I previously documented in 121 historical controversies (Salmon and Daly, 1998;Paulhus, Trapnell, and Chen, 1999;and Zweigenhaft and Von Ammon, 2000). These three studies, which involve six different samples, have all reported similar effect sizes to those previously documented by me. 10 ...
... In other words, radical revolutions especially tend to divide parents and their offspring. As we know from a series of studies conducted by Salmon (1998) and by Salmon and Daly (1998), family sentiments and loyalties tend to exhibit consistent birth-order differences, which appear to relate closely, moreover, to differences in parental investment (Hertwig, Davis, and Sulloway, in press). ...
... Nor is the debate any longer about the general nature of these effects, many of which can conveniently be described in terms of facets and dimensions in the Five Factor Model of personality. Moreover, insights growing out of neo-Darwinian theories of sibling competition and parental investment are helping us to explain some of these well-documented effects and, in many cases, are complementing our understanding of the proximate causal mechanisms that appear to implement them (Sulloway, 1996;Salmon and Daly, 1998;Mysterud, Drevon, and Slagsvold, 2001;Hertwig, Davis, and Sulloway, 2002;and Rohde et al., in press. What remains open to debate is the precise magnitude of birth-order effects, especially in behavior occurring outside the family. ...
Article
Frederic Townsend's critique of Born to Rebel (Sulloway, 1996) is based on an unfortunate pattern of misrepresentation and faulty empirical methods. First, the historical data in Born to Rebel are neither unrepresentative nor undisclosed. They were compiled with the help of 110 expert raters, who validated their representative nature and operationalized the principal outcome measures. Second, birth order is moderately associated with political radicalism, especially in real-life and within-family studies. Third, the meta-analytic data are statistically compelling for various behavioral attributes, although effect sizes are generally modest. Fourth, recent studies using large samples and anchored scales demonstrate the influence of birth order on a wide variety of personality traits, especially in within-family comparisons. In addition, the relationship between birth order and openness to radical innovation-highlighted in Born to Rebel-has been replicated by other researchers. Because Townsend fails to employ formal methods of hypothesis testing-relying instead on selected anecdotal examples, adversarial tactics, and an inadequate grasp of statistical principles - he has drawn numerous false conclusions about the influence of birth order.
... Behavioral studies have produced more consistent patterns of results (Sulloway & Zweigenhaft, 2010). While firstborns focus more on the family (Pollet & Nettle, 2007;Rohde et al., 2003;Salmon & Daly, 1998), laterborns often turn their focus outward to friends and other exchange partners, enabled by their prosocial tendencies in building support more broadly (Rohde et al., 2003;Salmon & Schumann, 2011). ...
... Sulloway and others (Sulloway, 1996;Salmon & Daly, 1998;Salmon 2003) have suggested that the favoring of firstborns (due to their greater reproductive value) and lastborns (due to older parents and lack of younger rivals) means that middleborns are the birth order that loses out on average in the parental investment game. As a result, they seem to focus more on developing non-kin reciprocal relationships outside the family unit (Salmon, 2003) and their personality traits seem to be a reflection of that. ...
... Much of the birth order literature has focused only on linear effects with the major focus being the difference between firstborns and then how traits or behaviors increase or decrease as birth order increases, such as intelligence or conscientiousness (Healey & Ellis, 2007;Kristensen & Bjerkedal, 2007;Sulloway, 1995). But a number of studies that have focused on family relationships (Salmon & Daly, 1998), parental investment (Kennedy, 1989), self-esteem (Henshaw, 2002;Kidwell, 1982), religiosity (Saraglou & Fiasse, 2003), and altruism (Courtiol, Raymond, & Faurie, 2009) have reported quadratic effects with the largest differences being between first and secondborns. The fact that linear and quadratic effects contributed significantly to our model emphasizes the importance of including both types of effects when modeling certain behaviors but also that researchers should consider the theory behind the relevance of birth order, whether the behavior or trait being examined is driven more by parental investment differences or sibling niches. ...
Article
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Much of the research on birth order has focused on individual differences in personality traits, with relatively few studies focused on aspects of social behavior other than sibling conflict. However, one would predict that the differences in parental investment and niche differentiation that shape personality differences between siblings would also influence other social relationships. In particular, middleborns may be more likely to prioritize non-kin relationships. This study investigated the impact of birth order on a number of measures of prosocial behavior. Results suggest that birth order has a moderate effect on prosociality such that later birth orders exhibit greater prosociality. However, both the linear and quadratic effects were significant and the quadratic was negative indicating that the greatest increase in prosociality is seen between first and secondborns, the rate of change decelerates as birth order and prosociality increase.
... Faurie et al. (2009) corroborated Hertwig et al. (2002) finding among sons of rural preindustrial Finns: middle-born sons appeared to produce significantly fewer offspring than first-or lastborn sons. Concerning relational capital biases, cues from studies of Western societies suggested that disadvantaged children might offset their parental-investment disadvantage by manipulating their networks through diversification of support, including other kin (Rohde et al. 2003;Salmon and Daly 1998) or nonkin (Salmon 2003;Salmon and Daly 1998). ...
... Faurie et al. (2009) corroborated Hertwig et al. (2002) finding among sons of rural preindustrial Finns: middle-born sons appeared to produce significantly fewer offspring than first-or lastborn sons. Concerning relational capital biases, cues from studies of Western societies suggested that disadvantaged children might offset their parental-investment disadvantage by manipulating their networks through diversification of support, including other kin (Rohde et al. 2003;Salmon and Daly 1998) or nonkin (Salmon 2003;Salmon and Daly 1998). ...
... Where material wealth is inherited, support network inequalities follow patterns of material inequalities, like the ones observed by Gibson and Gurmu (2011), suggesting that social capital in support networks reinforces material inequalities between brothers in the context of limited resources. When wealth is not inherited and all sons had equal access to land, other patterns of support network biases appeared, suggesting that social capital might at least partly offset the disadvantage of sons receiving the least cumulative parental investment, which is consistent with findings from Rohde et al. (2003), Salmon (2003), and Salmon and Daly (1998). Overall, our findings suggest that heritable wealth and land transfers, by influencing material and social capital, might have an important role in the emergence and persistence of inequality in this agricultural population, similar to findings by Smith et al. (2010). ...
Article
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Social support networks play a key role in human livelihood security, especially in vulnerable communities. Here we explore how evolutionary ideas of kin selection and intrahousehold resource competition can explain individual variation in daily support network size and composition in a south-central Ethiopian agricultural community. We consider both domestic and agricultural help across two generations with different wealth-transfer norms that yield different contexts for sibling competition. For farmers who inherited land rights from family, firstborns were more likely to report daily support from parents and to have larger nonparental kin networks (n = 180). Compared with other farmers, firstborns were also more likely to reciprocate their parents’ support, and to help nonparental kin without reciprocity. For farmers who received land rights from the government (n = 151), middle-born farmers reported more nonparental kin in their support networks compared with other farmers; nonreciprocal interactions were particularly common in both directions. This suggests a diversification of adult support networks to nonparental kin, possibly in response to a long-term parental investment disadvantage of being middle-born sons. In all instances, regardless of inheritance, lastborn farmers were the most disadvantaged in terms of kin support. Overall, we found that nonreciprocal interactions among farmers followed kin selection predictions. Direct reciprocity explained a substantial part of the support received from kin, suggesting the importance of the combined effects of kin selection and reciprocity for investment from kin.
... pois à medida que a idade aumenta, a manifestação do estilo democrático também se sobressai. Esse achado corrobora pesquisas anteriores (BOR-NSTEIN, 1998;CRUZ, 2005;MINUCHIN, 1988;SALMON;DALY, 1998), que demonstraram que com o amadurecimento do(a) filho(a), há uma adaptação no Estilo Parental dos pais, refletindo na necessidade de que apliquem métodos de educação e interação mais coerentes com o -303 -novo nível de desenvolvimento alcançado pela criança. Por exemplo, crianças menores que geralmente se comportam de modo mais agitado que as mais velhas, exigirão dos pais um maior nível de controle e afirmação de poder para contê-las. ...
... pois à medida que a idade aumenta, a manifestação do estilo democrático também se sobressai. Esse achado corrobora pesquisas anteriores (BOR-NSTEIN, 1998;CRUZ, 2005;MINUCHIN, 1988;SALMON;DALY, 1998), que demonstraram que com o amadurecimento do(a) filho(a), há uma adaptação no Estilo Parental dos pais, refletindo na necessidade de que apliquem métodos de educação e interação mais coerentes com o -303 -novo nível de desenvolvimento alcançado pela criança. Por exemplo, crianças menores que geralmente se comportam de modo mais agitado que as mais velhas, exigirão dos pais um maior nível de controle e afirmação de poder para contê-las. ...
Chapter
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Silva, M. F., & Roazzi, A. (2021). “Você está de castigo!”: Relação entre os estilos parentais de mães de crianças em idade escolar e variáveis sociodemográficas. In S. A. N. Mascarenhas & V. F. Pinto, (Eds.), Ensino, Cidadania e Inclusão: Ecos do Século XXI (pp. 299-316). São Paulo: Alexa Cultural e EDUA. ISBN - 978-65-89677-86-4 https://bit.ly/388EKVv //// Os Estilos Parentais representam um tema central em pesquisas sobre parentalidade e desenvolvimento cognitivo e socioemocional infantil. O fundamento repousa sobre a responsabilidade primária que os pais têm de acolher, suprir as necessidades e orientar o comportamento dos(as) filhos(as), desenvolvendo uma relação com poderosos laços afetivos, de modo que a criança se torne receptiva à influência dos mesmos, o que reflete, de acordo com alguns autores (KAWABATA et al., 2011; SARTAJ; ASLAM, 2010; HOEVE et al., 2009), em vários aspectos do ajustamento socioemocional da criança, podendo inclusive se desdobrar em psicopatologias, como ansiedade e depressão, por exemplo. No que tange à definição, o Estilo Parental pode ser compreendido como um conjunto de ações relacionadas à disciplina, à hierarquia e ao suporte emocional dos pais para com os filhos (BENCHAYA et al., 2011) ou como o clima emocional dentro do qual, as práticas parentais – comportamentos emitidos pelos pais na educação dos filhos – são implementadas (DARLING; STEINBERG, 1993). Nesse sentido, encontra-se também a definição de Reppold et al. (2002, p. 23) sobre os estilos: “[...] são manifestações dos pais em direção a seus filhos, que caracterizam a natureza da interação entre esses”. A abordagem tipológica é uma das mais utilizadas no estudo da parentalidade, pois classifica os pais com base em seus comportamentos e interações com os (as) filhos(as), agrupando-os em diferentes Estilos Parentais (HART; NEWELL; OLSEN, 2003; PARKE; BURIEL, 1998). Em vista disso, destaca-se a teoria de Diana Baumrind (1966, 1971) sobre a parentalidade, considerada um marco nos estudos sobre o tema que desde então vem sendo amplamente referenciada na literatura e inspirando a construção de instrumentos que possibilitam a associação dos pais aos Estilos Parentais por ela propostos: democrático, autoritário e permissivo. Um instrumento elaborado para tal e que merece destaque é o Questionário de Dimensões e Estilos Parentais - QDEP (Parenting Styles and Dimensions Questionnaire: Short Version - PSDQ) de Robinson et al. (2001), composto por 32 itens que descrevem comportamentos dos pais direcionados à interação com seu (sua) filho(a), sendo considerado por Locke e Prinz (2002) como um dos poucos instrumentos cujas escalas de medidas parentais de disciplina e cuidado têm qualidades psicométricas satisfatórias.
... Evolutionary perspectives have been productively applied to the study of familial conflict across a number of contexts including spousal homicide Wilson and Daly 2004), infanticide (Daly andWilson 1984, 1994a), child abuse (Daly andWilson 1986, 1994b), parent-offspring conflict (Salmon 2007;Schlomer et al. 2011), and sibling relationships in general (Pollet 2007;Salmon and Daly 1998), as well as siblicide Michalski et al. 2007). ...
... Birth order. Evidence suggests that middleborn children perceive their parents in a less positive light than do first-and lastborns, preferring to have a close relationship with a friend over kin Salmon and Daly 1998). Firstborns are more likely to maintain a close contact with siblings and invest more in siblings relative to laterborns ). ...
Book
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This volume is an interdisciplinary exploration of our understanding of the causes and consequences of violence. Represented in its chapters are noted scholars from a variety of fields including psychology, anthropology, law, and literature. The contributions reflect a broad scope of inquiry and diverse levels of analysis. With an underlying evolutionary theme each of the contributors invoke their separate areas of expertise, offering empirical and theoretical insights to this complex subject. The multi-faceted aspect of the book is meant to engender new perspectives that will synthesize current knowledge and lead to a more nuanced understanding of an ever timely issue in human behavior. Of additional interest, is a foreword written by world renowned psychologist, Steven Pinker, and an afterword by noted evolutionary scholar, Richard Dawkins. © Springer Science+Business Media New York 2014. All rights are reserved.
... We briefly describe one piece of this picture: Salmon's work on family sentiments. In a series of studies, Salmon (1998Salmon ( , 1999Salmon & Daly, 1998) uncovered large and consistent middleborn effects when she asked college students (19-to 22year-olds) about kinship and family ties. For instance, when asked to whom they would turn for emotional or financial support, first and lastborns were significantly more likely than middleborns to nominate a parent in both scenarios (by an overall factor of 1.5). ...
... For instance, when asked to whom they would turn for emotional or financial support, first and lastborns were significantly more likely than middleborns to nominate a parent in both scenarios (by an overall factor of 1.5). First and lastborns were also significantly more likely to nominate their mothers as the person to whom they felt the closest, a pattern that was replicated in three separate studies (Salmon & Daly, 1998, see also Kennedy, 1989;Rohde et al., 2002). Middleborns' family sentiments are also associated with less frequent contact with parents and grandparents. ...
Article
The equity heuristic is a decision rule specifying that parents should attempt to subdivide resources more or less equally among their children. This investment rule coincides with the prescription from optimality models in economics and biology in cases in which expected future return for each offspring is equal. In this article, the authors present a counterintuitive implication of the equity heuristic: Whereas an equity motive produces a fair distribution at any given point in time, it yields a cumulative distribution of investments that is unequal. The authors test this analytical observation against evidence reported in studies exploring parental investment and show how the equity heuristic can provide an explanation of why the literature reports a diversity of birth order effects with respect to parental resource allocation.
... Na pomen razlikovanja med drugo-oz. srednjerojenimi in pozneje rojenimi otroki so opozorili že Kidwell (1982), Kennedy (1989), Salmon in Daly (1998) ter Saroglou in Fiasse (2003), ko so ugotavljali, da imajo srednjerojeni otroci najnižjo samopodobo in so deležni najmanj starševske podpore (npr. pri učenju). ...
... Healey in Ellis, 2007;Sulloway, 1996), nekatere so narejene na družinah s tremi otroki (npr. Nyman, 1995;Salmon in Daly, 1998), le izjemoma najdemo raziskave z več kot tremi otroki (npr. Dixon, Reyes, Leppert in Pappas, 2008) ali takšne, ki med seboj primerjajo otroke iz družin z dvema in tremi otroki (npr. ...
Article
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The present study attempts to determine the relationship between an individual’s birth order and his/her personality traits as described in terms of the Big Five. Four dimensions of the Big Five (Extraversion, Openness, Neuroticism, Agreeableness, and Conscientiousness) and their corresponding facets were measured with the IPIP-NEO 300 questionnaire, which was translated and adapted for Slovenian respondents. The questionnaire was completed by 177 individuals, who were divided into three groups: first-born, second-born and later-born children. The results show that the group of first-born and the group of second-born children (as compared with the third group) do not differ significantly in any personality trait, while the group of later-born children differs significantly from the other two with respect to eight out of twenty-eight measured traits. The comparison of personality traits did not yield similar results to those reported by other authors.
... As a consequence, they might be inclined to take risks (Bertoni and Brunello 2016;Wang et al. 2009) and trust unknown persons. The fourth channel is the strength of family ties, provided that birth order influences familial sentiment (Kennedy 1989;Kidwell 1981 Salmon andDaly 1998) and that strong family ties endanger trust in strangers (Ermisch and Gambetta 2010; Yamagishi 1994 andYamagishi et al. 1998). These potential explanations lead to alternative hypotheses. ...
... In other words, strong and stable relations, such as family ties, would reduce social uncertainty by providing 'assurance' of mutual cooperation (Yamagishi and Yamagishi 1994), and consequently less need for relying on -and hence trusting -persons outside these relations (Ermisch and Gambetta 2010). 2 A rationale for why family ties vary by birth order is offered by the evolutionary psychology literature, which suggests that firstborns and lastborns consider their parents as sources of support to a greater extent than middleborns do. In facts, being the first or the last born is shown to positively predict familial sentiment, as proxied for by reliance on parents as social supports, relevance of one's family to one's self-concept, and one's interest in family (Kennedy 1989;Kidwell 1981 Salmon andDaly 1998). Hence we expect an inverse ushaped relationship between birth order and trust, provided that middleborns are less familyoriented than their siblings, and that trust is low when family ties are strong. ...
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The renewed interest by the economic literature in the effect of birth order on children's outcomes has neglected trust as a long-term output of familial environment. Acknowledging childhood as a crucial stage of life for the formation of social preferences, we go deeper into the early-life determinants of trust, a widely recognized driver of socioeconomic success. We analyze if and how differences in the order of birth predict heterogeneous self-reported trust levels in Britain. We draw hypotheses from psychology, economics and sociology, and test alternative explanations to the association between birth order and trust. Relying on an index measuring birth order independently from sibship size, we find a negative and robust effect of birth order, with laterborns trusting less than their older siblings. This effect is not accounted for by personality traits, strength of family ties, risk aversion and parental inputs. It is only partially explained by complementary human-capital outcomes, and it is robust when we use alternative dependent variables and control for endogenous fertility. Multilevel estimates suggest that trust is mostly driven by within-rather than between-family characteristics. The effect of birth order is eclipsed by education outcomes only for women, while it is counterbalanced by mother's education for the entire sample, thereby leading to relevant policy implications.
... A set of studies using non-representative samples of university students has found that middleborns receive less parental investment, rate their parents as less supportive and are less close to their parents compared to firstborns and lastborns (e.g. Salmon & Daly, 1998;Salmon, 2003;Rohde et al., 2003). However, some other small-scale studies have not found evidence for the neglected middleborn hypothesis. ...
... For instance, Hardman and colleagues (2007) used data on school-aged children and younger adults to test the neglected middleborn hypothesis. The main purpose of their investigation was to replicate the findings of the prior study by Salmon and Daly (1998), however, they did not find support for the birth order effects in either study generation. The mixed findings could be related to small sample size and the fact that these studies were able to take into account only limited amount of background variables. ...
Article
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The neglected middleborn hypothesis predicts that middleborn children should have a worse relationship quality with their parents compared to firstborn and lastborn children. However, prior studies investigating this question have produced mixed results. In this study, the neglected middleborn hypothesis was tested using a large-scale, population-based sample of younger adults from Germany. Relationship quality was measured by contact frequency, emotional closeness, intimacy and amount of conflict participants reported towards their mothers and their fathers. It was found that middleborns reported less intimacy towards their mothers than lastborns. However, in all other cases, middleborns did not differ from firstborns or lastborns in their relationship quality with their mothers and fathers. Thus, the study did not find convincing support for the neglected middleborn effect.
... An exception to this generalization involves youngest children born toward the end of a woman's reproductive career. These children also tend to be favored, since they cannot be replaced (Salmon and Daly, 1998). ...
... The kinds of birth-order effects that are observed during radical historical revolutions may depend as much on differences in 'family sentiments' as they do on personality. As Salmon and Daly (1998) have shown, firstborns (and to a lesser extent lastborns) are more strongly attached to the family system than are middle children. Historically, radical revolutions have tapped differences in family sentiments in two important ways. ...
Chapter
Throughout much of the world, eldest children are privileged, socially and economically, over their younger siblings. For this reason, firstborns tend to exhibit greater filial loyalty compared with laterborns. Because sibling order is a proxy for individual differences in age, size, and status, it affects sibling strategies in competition for parental investment. Differences in sibling strategies in turn exert a modest influence on personality and social behavior, reflecting a Darwinian process by which brothers and sisters seek to reduce direct competition through the adoption of unique family niches. Eldest siblings, who typically occupy the niche of a surrogate parent, tend to be more conscientious, achievement oriented, and conforming to authority than are their younger siblings; whereas laterborns, who cultivate low-power strategies, are often more agreeable, open to experience, and extraverted in the sense of being fun-loving and excitement-seeking. These differences in personality are displayed in various historical trends, as laterborns have often championed radical revolutions and reform movements - including the Protestant Reformation, numerous political revolutions, and radical revolutions in science.
... In this respect, siblings would acquire different personality traits according to birth order. In particular, firstborns would be the most conservative, in the attempt to preserve their privileged status and birth prerogatives, laterborns would be more nonconforming and altruistic, whilst middleborns would be the least close to their parents as a consequence of the fact that they were the only offspring who never experienced a period of exclusive parental investment (Rhode et al., 2003;Salmon & Daly, 1998). However, some factors could bias and modulate such a model of family dynamics, namely socio-economic status, sibship size, and birth interval (Emst & Angst, 1983;Sulloway, 1997). ...
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Human child survival depends on adult investment, typically from parents. However, in spite of recent research advances on kin influence and birth order effects on human infant and child mortality, studies that directly examine the interaction of kin context and birth order on sibling differences in child mortality are still rare. Our study supplements this literature with new findings from large-scale individual-level panel data for three East Asian historical populations from northeast China (1789–1909), northeast Japan (1716–1870), and north Taiwan (1906–1945), where preference for sons and first-borns are common. We examine and compare male child mortality risks by presence/absence of co-resident parents, grandparents, and other kin, as well as their interaction effects with birth order. We apply discrete-time event-history analysis on over 172,000 observations of 69,125 boys aged 1–9 years old. We find that in all three populations, while the presence of parents is important for child survival, it is more beneficial to first/early-borns than to later-borns. Effects of other co-resident kin are however null or inconsistent between populations. Our findings underscore the importance of birth order in understanding how differential human parental investment may produce child survival differentials between siblings.
... sumed that the main difference in family-related experiences is between the firstborn child and laterborn children, meaning that secondborn and thirdborn chil- dren etc. are all merged into a category of laterborn children, although previous research also pointed out significant differences of youngest or middleborn children (e.g., C. Salmon, 2003;C. A. Salmon & Daly, 1998). And last but not least, single children (the only children in a family) are frequently subsumed into the firstborn category. ...
... In contrast to middle-born, last-born children would benefit from another advantage: when parents − especially mothers − reach the end of their reproductive period of life, the last-born will represent the last child they will ever have. The parents tend to increase − as much as possible − their efforts for the last-born, the 'baby' of the family, the last piece of family history ( Salmon & Daly, 1998). More generally, if the dilution of resources results in worse living conditions for some children, especially due to lower quality and smaller amounts of food ( Horton, 1988), less investment and more limited quantity of parental time ( Lindert, 1977;Price, 2008) dedicated to them, this theoretical model could explain differences in the quality of life within the family. ...
Article
This paper is intended as a contribution to the debate on the determinants of physical stature in the past and it specifically investigates whether, in Sardinia, height − considered as a proxy of the share of household resources allocated to a child’s growth − was influenced by the number of brothers and sisters amongst whom parents had to distribute available resources. This study is limited to the male population, because military records represent the only source at our disposal providing historical data on height. The community studied is the town of Alghero, located on the north-western coast of Sardinia, at the turn of the twentieth century. We have adopted a longitudinal approach, thanks to the rich dataset reconstructed for Alghero, using different sources including family, socioeconomic and anthropometric indicators. The results, in line with the resource dilution hypothesis, show that competition within the household was of some importance and that the effects on height due to scarcity of resources were particularly evident amongst farmers, the most representative socioeconomic status group in Alghero. A significant contribution to the stature reached in adulthood was also given by the socioeconomic status of the family or else by other individual characteristics
... The birth of a sibling may be even more challenging to infants who have older siblings. Middleborn children are at increased risk of parental underinvestment (Salmon & Daly, 1998; Sullaway, 2011), a situation that may be especially disadvantageous for those who are unweaned infants. Attenuated expressions of jealousy by the age of 4 years have also been observed outside contexts that involve lactation. ...
Article
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In this article, nascent jealousy’s ultimate foundation is theorized as an adapted psychological mechanism that evolved in the environment of evolutionary adaptedness (EEA) to prepare 1-year-olds for defending against premature weaning upon the closely spaced birth of a sibling. This position rests on evidence that nascent jealousy is expressed through jealousy protest, a constellation of caregiver-directed protests and bids for exclusive attention, and evidence that its onset occurs at approximately 9 months of age. Given that the period of human gestation is 9 months, we propose that jealousy protest’s form and timing were compelled by the possibility that the end of an infant’s first year could be met by competition with a newborn sibling. That possibility placed infants at risk of malnutrition and mortality due to entailing the loss of exclusive access to mother’s milk, while infants were at an age when they were still heavily reliant on breast milk for survival. At this juncture, threat posed by the birth of a sibling was compounded by conditions of the EEA, where the sole viable source of breast milk was an infant’s mother, and her supply of milk was sufficient for sustaining only one child at a time. We conclude by offering suggestions for future research and discuss implications for the theory of parent–offspring conflict as a foundation of adaptations in children.
... Studies have also shown that middleborns are not as close to their parents as are their siblings. For example, middleborns are less likely to turn to parents for emotional support in response to traumatic events (Rohde et al. 2003;Salmon and Daly 1998). This finding is a good example of the U-shaped relationship that is expected between birth order and some cognitive and behavioral outcomes. ...
... When the recent between-family designs do reach significance, they tend to support Sulloway (Davis, 1994;Trapnell, 1995;Wehr and Paulhus, 2000). Other within-family studies have supported Sulloway's predictions (Salmon and Daly, 1998;Sulloway, in press). Even the recent report by Jefferson, Herbst, and McCrae (1998)?cited as a refutation of Sulloway?actually ...
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The notion that birth order bears a systematic relation to personality was commonly thought to have succumbed to the formidable attack from Ernst and Angst (1983). The 1996 publication of Frank Sulloway's book Born to Rebel , however, breathed new life into a proposition that most social scientists thought was a dead horse. In response to the book, Townsend (this issue) insists that Sulloway's extraordinary measures to revive this dead horse were unwarranted. Apparently fearing that too many readers have taken the book seriously, Townsend attacks both the contemporary and historical evidence offered by Sulloway.
... However, prior studies have produced mixed results. While some non-representative studies have provided evidence for the prediction (Salmon and Daly, 1998;Salmon, 1999Salmon, , 2003, more recent investigations utilizing large-scale and population-based data have not found support for the neglected middleborn hypothesis (Pollet andNettle, 2007, 2009a;Tanskanen and Danielsbacka, 2014;Steinbach and Hank, 2018;Tanskanen and Danielsbacka, 2019). Instead of birth order, age and birth spacing (i.e., the age difference between siblings) are important factors shaping sibling relationships. ...
... According to the neglected middleborn hypothesis, firstborn and lastborn children should report closer family ties than middleborns, but prior studies have provided mixed results. Using non-representative data on US college students, a set of studies have indeed indicated that middleborns are less family-oriented than other birth orders (Salmon, 1999;Salmon, 2003;Salmon & Daly, 1998). In contrast, two later studies that used large-scale and population-based data from the Netherlands found no support for the neglected middleborn hypothesis, although it was found that compared with laterborns, firstborns reported more frequent contact and better sibling relationship quality (Pollet & Nettle, 2007, 2009. ...
Chapter
This chapter considers relations between adult siblings, measured by kin support, emotional closeness, practical help, financial support and contact frequency. Prior studies have indicated that sibling attachment is created early in childhood through certain cues, including coresidence and shared maternal care, meaning that increased time siblings have spent together during childhood and maternal perinatal association (i.e. seeing one’s own mother nurse a newborn baby) tend to influence adult sibling relations. Also, parental unequal treatment experienced in childhood or adolescence can be remembered for a long time and it may shape sibling ties in adulthood. In addition, it has been detected that sister-sister pairs are closer compared to other sibling constellations; increased age difference between siblings predicts decreased contact and support between sisters and brothers; full siblings are closer to one another compared to half or step siblings; and longer geographical distance between siblings is associated with decreased probability of contact and support. These prior findings are discussed with reference to evolutionary, social psychological and sociological theories about sibling altruism. At the end of the chapter, limitations of existing studies are presented and themes for future investigations are introduced.
... i tworzą własną historię (Davies 2016;Richardson i Richardson 2001;Salmon i Daly 1998). ...
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This paper explores the presence of norms of solidarity in widespread concepts of the love binding siblings, and in the experience of having siblings. The attributes of love between siblings, the advantages and disadvantages of having siblings, and degrees of confidence in nearest kin were analyzed on the basis of research using the auditory survey technique (with the majority of the questions being open) conducted in the years 2015-2016 on 226 students in their first year of bachelor's degree studies at the Department of Social Sciences of the UAM. The quantitative and qualitative data makes it possible to conclude that in this time of a denormalization and desolidarization of family ties the relationship between siblings in early adulthood has resisted these processes. The essence of the relationship is altruism, in the sense of support, trust, dedication, and selflessness. An attempt is also made in the article to point to the source for viewing siblings in these categories.
... Empirical controlled studies have reported that first-borns are more conscientious and more responsible than later-borns who, by contrast, appear to be more agreeable, accommodating and affectionate (Healey & Ellis, 2007). However, a relevant difference between middle children and the last-born in families with more than two children has been suggested, in that first-and last-borns will both see their parents and familial resources as dependable sources of support to a greater degree than will middle-borns (Bu & Sulloway, 2016;Salmon & Daly, 2002). Moreover, a large body of literature investigating consequences of birth order on individual behaviors and attitudes has revealed consistent birth order differences for many traits and behaviors such as antisocial behaviors (e.g., Bank et al., 2004) and reproductive choices (e.g., Milne & Judge, 2009). ...
Article
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Birth order may foster specific roles for individuals within the family and set in train a dynamic that influences the development of specific behaviors. In this paper, we explored the relationship between birth order, sex, timing of sexual initiation, and its consequences for risky sexual behavior and sexual health. We conducted a path analysis to simultaneously estimate direct and indirect effects using data from the National Survey of Sexual Attitudes and Lifestyles (NATSAL-3). Whereas women born as only-children were more likely to sexually debut at later ages, middle-child boys were significantly more prone to initiate sexual intercourse earlier compared with first-borns. As expected, early sexual initiation was associated with riskier behaviors and sexual health outcomes. These associations were partially moderated by siblings role as confidants about sexuality. Our findings have implications for preventive programs aimed at promoting healthy sexual debuts and behaviors over the life span.
... 46 Model 2 additionally adjusted for SEP (parental education, parental occupation, and household income per capita). 47,48 Model 3 additionally adjusted for mother's place of birth, 49 birth order of the participants, 50 secondhand smoke exposure at home, 51 parental age at birth, 52 gender-specific birth weight z score (which reflects fetal development [relative to the 2006 World Health Organization child growth standards]), 53 BMI z score at 7 years (relative to the 2007 World Health Organization growth reference), 54 and parental marital status. 55 Multiple imputation was used to predict missing exposures and confounders based on a flexible additive regression model. ...
Article
Objective: Timing of onset of puberty has fallen, with profound and detrimental consequences for health. We examined the associations of earlier onset of puberty with the presence of depression in early to middle adolescence. Methods: The study examined prospective adjusted associations of age at onset of puberty, based on clinically assessed Tanner stage for breast/genitalia and pubic hair development, and self-reported presence of depression, assessed from the 9-item Patient Health Questionnaire on average at 13.6 years (n = 5795 [73%]). These factors were examined by using multivariable logistic regression in a population-representative Hong Kong Chinese birth cohort (ie, the "Children of 1997"). We also assessed whether associations varied according to gender. Results: Association of age at onset of breast/genitalia development with the presence of depression varied according to gender. Earlier onset of breast development was associated with higher risk of the presence of depression (odds ratio, 0.83 per 1 year increase in age of onset [95% confidence interval, 0.70 to 0.98]) adjusted for age, socioeconomic position, mother's place of birth, birth order, secondhand smoke exposure, parental age, survey mode, gender-specific birth weight z score, BMI z score at 7 years, and parental marital status. In boys, similarly adjusted, age at onset of genitalia development was unrelated to the presence of depression. Earlier age at onset of pubic hair development was unrelated to the presence of depression in girls and boys. Conclusions: Early onset of breast development was associated with high risk of the presence of depression. Whether these findings are indicators of the effects of hormones or transient effects of social pressures remain to be determined.
... Across human societies, parents, and predominantly fathers, often show stronger preferences for and invest more in sons than daughters (Puri et al., 2011;Raley & Blanchi, 2006;Stinner & Mader, 1975), while mothers tend to favor firstborn children more than fathers (Salmon et al., 2012). Moreover, firstborn children often reported to be closest to their mothers (Salmon & Daly, 1998). The fact that namesaking is significant mostly when interacting with sex and primogeniture suggests that namesaking plays an additive role-it enhances the effect of the biological factors, which have the primary influence on parental investment. ...
Article
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Namesaking (naming a child after a parent or other relative) can be viewed as a mechanism to increase perceived parent-child similarity and, consequently, parental investment. Male and, to a lesser extent, firstborn children are more frequently namesakes than female and later-born children, respectively. However, a direct link between namesaking and parental investment has not been examined. In the present study, 632 participants (98 men and 534 women) from Central Europe indicated their first name, sex, birth order, number of siblings, sexual orientation, socioeconomic status, paternal and maternal first names, as well as relationship quality with, and time and financial investment they received from, both parents during childhood. Mixed-effects models revealed associations between namesaking and parental investment. However, the effect of namesaking often appeared significant only in interaction with specific predictors, such as sex and primogeniture. It suggests instead that namesaking has an additive effect-it enhances the effect of biological factors on parental investment. In general, we found evidence for the bias in parental investment linked to name similarity among both parents, and support for the hypothesis that namesaking serves as a mechanism to increase paternity confidence and, thus, paternal investment. The effect of namesaking influences only certain types of parental investment-namely, those at the level of relationship quality. In addition, nonheterosexual orientation was the strongest negative predictor of paternal investment. Our study extends the research on parental investment by showing that cultural mechanisms, such as namesaking, can also exert some influence on parental rearing behavior.
... First-born children are described as being under increased pressure to conform to adults' expectations (Baskett 1985) and are more likely to report higher levels of parental control and influence, with parental discipline weakening from first-born to last-born (Hotz and Patano 2015). First-borns also appear to have stronger familial sentiments: Salmon and Daly (1998) identify first-borns as more likely than middle-or last-borns to nominate parents as figures they would turn to under duress, and to choose their mothers as the person to whom they feel closest. Middle-borns, in particular, appear to have markedly less close relationships with their parents, with Kidwell (1981) finding that middle-borns were significantly less likely than firstor last-borns to report parental reasonableness and supportiveness. ...
Article
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This analysis set out to identify associations between birth order and sexual health outcomes, focusing on family involvement in sex education and early sexual experiences. The third National Survey of Sexual Attitudes and Lifestyles is a stratified probability sample survey of 15 162 men and women aged 16–74 in Britain. Logistic regression was conducted to identify odds ratios for the association between birth order and sexual health outcomes. Multiple logistic regression was performed adjusting for socio-demographic factors and sibling number. Middle-born and last-born men had lower odds of reporting ease talking to parents about sex around age 14 and learning about sex from their mothers. Last-born women had lower odds of reporting a parental main source of sex education or having learned about sex from their mother. Findings represent an exploratory analysis in an under-researched area, and provide the basis for further research on the association between birth order and parental involvement in sex education, as well as the role and impact of sex education provided by older siblings.
... Across human societies, parents, and predominantly fathers, often show stronger preferences for and invest more in sons than daughters (Puri et al., 2011;Raley & Blanchi, 2006;Stinner & Mader, 1975), while mothers tend to favor firstborn children more than fathers (Salmon et al., 2012). Moreover, firstborn children often reported to be closest to their mothers (Salmon & Daly, 1998). The fact that namesaking is significant mostly when interacting with sex and primogeniture suggests that namesaking plays an additive role-it enhances the effect of the biological factors, which have the primary influence on parental investment. ...
Article
Full-text available
Namesaking (naming a child after a parent or other relative) can be viewed as a mechanism to increase perceived parent-child similarity and, consequently, parental investment. Male and, to a lesser extent, firstborn children are more frequently namesakes than female and later-born children, respectively. However, a direct link between namesaking and parental investment has not been examined. In the present study, 632 participants (98 men and 534 women) from Central Europe indicated their first name, sex, birth order, number of siblings, sexual orientation, socioeconomic status, paternal and maternal first names, as well as relationship quality with, and time and financial investment they received from, both parents during childhood. Mixed-effects models revealed associations between namesaking and parental investment. However, the effect of namesaking often appeared significant only in interaction with specific predictors, such as sex and primogeniture. It suggests instead that namesaking has an additive effect-it enhances the effect of biological factors on parental investment. In general, we found evidence for the bias in parental investment linked to name similarity among both parents, and support for the hypothesis that namesaking serves as a mechanism to increase paternity confidence and, thus, paternal investment. The effect of namesaking influences only certain types of parental investment-namely, those at the level of relationship quality. In addition, nonheterosexual orientation was the strongest negative predictor of paternal investment. Our study extends the research on parental investment by showing that cultural mechanisms, such as namesaking, can also exert some influence on parental rearing behavior.
... Further, age of acquisition may be later, and the role of teaching may be stronger, for learning complex cultural norms and religious practices than for readily observable subsistence tasks. Beyond task difficulty, various studies suggest that birth order may impact aspects of personality and fertility across cultures (e.g., Draper and Hames 2000;Salmon and Daly 1998) and may also influence how and from whom social learning occurs. Cross-cultural studies comparing foragers with farmers can also shed light on how aspects of social structure (hierarchy vs. egalitarianism, sedentarism vs. mobility) affect how and from whom children learn. ...
Article
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Aspects of human life history and cognition, such as our long childhoods and extensive use of teaching, theoretically evolved to facilitate the acquisition of complex tasks. The present paper empirically examines the relationship between subsistence task difficulty and age of acquisition, rates of teaching, and rates of oblique transmission among Hadza and BaYaka foragers from Tanzania and the Republic of Congo. We further examine cross-cultural variation in how and from whom learning occurred. Learning patterns and community perceptions of task difficulty were assessed through interviews. We found no relationship between task difficulty, age of acquisition, and oblique transmission, and a weak but positive relationship between task difficulty and rates of teaching. While same-sex transmission was normative in both societies, tasks ranked as more difficult were more likely to be transmitted by men among the BaYaka, but not among the Hadza, potentially reflecting cross-cultural differences in the sexual division of subsistence and teaching labor. Further, the BaYaka were more likely to report learning via teaching, and less likely to report learning via observation, than the Hadza, possibly owing to differences in socialization practices.
... Finally, it deserves to be mentioned that there is also a literature discussing the potential differences between middle-and last-borns in larger families (e.g. Kidwell, 1982;Salmon & Daly, 1989). However, since from existing theories, it is less evident how parental and own aspirations may vary between these groups, and due to a somewhat limited number of cases, the current study only distinguishes between firstand later-borns. ...
Article
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The purpose of the study was to explore the life circumstances of singletons and first-born children, and the importance of the size of the sibling group, by focusing on scholastic aspirations, both on part of the children themselves, but also of their parents. The study used data collected with around 3650 children and their parents, and apart from information on the children’s and their parents’ explicit aspirations, there was also information on the children’s estimation of their parents’ aspirations. While only small differences in parental explicit aspirations were found, substantial differences were found with respect to the children’s own aspirations and their estimations of those of their parents. Only children were more likely to estimate high scholastic aspirations on part of their parents, as were first-borns with siblings. First- also tended to express higher scholastic aspirations themselves. Theoretically, strategic parenting and role specialization were used to explain the results.
... Th is and the order-induced diff erential niche-picking of siblings lead to a variety of personality diff erences between siblings (Sulloway, 1996(Sulloway, , 2007, typically of small magnitude. Particularly, middleborns show less family solidarity and identity than do fi rstborns or lastborns (Salmon, 2003 ;Salmon & Daly, 1998 ). ...
Article
The four categories of grandparents differ in their investment in grandchildren, with the maternal grandmother investing the most and taking an outstanding position, followed usually by the maternal grandfather, the paternal grandmother, and the paternal grandfather. This discriminative grandparenting is manifest in many investment proxies, like contact and care, expressions of affection, grandchild survival, and others. The recurrent rank order of the four grandparent categories is best explained by two basic reproductively relevant variables: relationship uncertainty and sex-specific reproductive strategy. The expression of these variables is moderated by several conditions, among others residential proximity, marital status of grandparent, family size, type of joint activity, age of child, and grandparent-grandchild similarity. In natural fertility populations, the availability of the maternal grandmother increases chances for child survival. In industrialized countries, the positive impact of grandparental support is still evident in high-risk family conditions under circumstances of duress.
... Prvorođeni su trošili više od kasnije rođenih, davali više roditeljima, braći te bakama i djedovima. Ti nalazi podržavaju tezu da se prvorođeni snažnije identificiraju s roditeljima i autoritetom (bake i djedovi) te da identifikacija oblikuje njihovu osobnost u ranoj dobi zbog čega su više orijentirani na obitelj te pod jačim utjecajem rodbinskih veza (Salmon i Daly, 1998). Novija istraživanja na temu utjecaja redoslijeda rođenja na razvoj osobnosti (Marini i Kurtz, 2011;Rohrer, Egloff i Schmukle, 2015), suprotno prethodnim nalazima Sullowaya (1996), nisu pokazala postojanje efekta redoslijeda rođenja na razvoj osobnosti. ...
Article
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As a universal phenomenon, gift giving is frequently studied by various disciplines and fields within the social sciences, including evolutionary psychology. Numerous sex differences were observed in the variety of patterns of gift giving which evolved as an adaptive mechanism towards securing higher reproductive success. On top of that, other effects affecting gift giving were documented, such as the effect of genetic and social relationships and the birth-order effect. Most of the findings are in accordance with the core evolutionary theories, while offering explanations of the adaptive value of gift giving as well as its underlying motives.
... Further, age of acquisition may be later, and the role of teaching may be stronger, for learning complex cultural norms and religious practices than for readily observable subsistence tasks. Beyond task difficulty, various studies suggest that birth order may impact aspects of personality and fertility across cultures (e.g., Draper and Hames 2000;Salmon and Daly 1998) and may also influence how and from whom social learning occurs. Cross-cultural studies comparing foragers with farmers can also shed light on how aspects of social structure (hierarchy vs. egalitarianism, sedentarism vs. mobility) affect how and from whom children learn. ...
Preprint
Aspects of human life history and cognition, such as our long childhoods and extensive use of teaching, theoretically evolved to facilitate the acquisition of complex tasks. Using interviews conducted with Hadza and BaYaka foragers from Tanzania and the Republic of Congo, the present paper empirically examined the relationship between subsistence task difficulty and age of acquisition, rates of teaching, and rates of oblique transmission. We further examined cross-cultural variation in how and from whom learning occurred. We found no relationship between skill difficulty, age of acquisition, and oblique transmission, and a weak but positive relationship between skill difficulty and rates of teaching. While same-sex transmission was normative in both societies, BaYaka transmission was female-biased and Hadza transmission male-biased, potentially because the latter have a stronger sexual division of labor than the former. Further, the BaYaka were more likely to report learning via teaching, and less likely to report learning via observation, than the Hadza, possibly due to differences in socialization practices. These findings suggest that patterns of transmission are highly variable across cultures.
... This leads to laterborns to incur in more risks, as the costs of risk taking are reduced whenever life expectancy is reduced (Daly and Wilson 1988) (Wang et al. 2009). A nal possible explanation is that laterborns may assume greater risks to establish alliances with peers as part of a strategy to compensate for receiving less parental investment (Salmon and Daly 1998) (Sulloway 1996) (Wang et al. 2009). ...
Article
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Several studies have shown that birth order and the sex of siblings may have an influence on individual behavioral traits. In particular, it has been found that second brothers (of older male siblings) tend to have more disciplinary problems. If this is the case, this should also be shown in contact sports. To assess this hypothesis we use a data set from the South Rugby Union (URS) from the region of Bahía Blanca, Argentina, and information obtained by surveying more than four hundred players of that league. We find a statistically significant positive relation between being a secondborn male rugby player with an older male brother and the number of yellow cards received.
Article
ערך הבוחן היבט מוכר פחות במחקר על השפעת סדר ההולדה על התנהגות הילדים, והוא מקומם של מי שאינם הבכורים, ה"סנדוויץ" או האחרונים.
Article
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Kin terms such as "brothers," "sisters," and "motherland" are frequently used in both political and patriotic speech. Johnson (1986, 1987) has argued that this use of kin terms in patriotic or rhetorical speech can be predicted on the basis of evolutionary psychology. He has suggested that the human inclination toward nepotistic behavior can be called forth by the successful manipulation of kin terminology. In this study, two hypotheses were examined concerning the evocativeness of kin terminology in political speech and the influence of birth order on the effectiveness of such terminology. The first hypothesis was that kin terms would be more effective than more distant relationship terms (like "friend") in evoking a positive response. Kin terms elevated agreement with the views expressed in the speech that the subjects heard. The second hypothesis, that middleborns would be less likely to respond to such kin term usage than first or lastborns, was based on previous work on birth order and family relations (Salmon and Daly, in press). And in fact, middleborns were less likely to be influenced by the use of kin terms than first or lastborns in this study.
Article
Sibling relations are by nature ambivalent with high levels of both altruistic helping and competition. Higher relatedness is often assumed to reduce the occurrence of conflicts between siblings, but evidence of this has been scarce and mixed. Siblings typically compete over resources and parental attention, and parental constellations vary with sibship types. Since full-siblings compete over the same two biological parents, while half-siblings have only one shared biological parent and often a higher number of parents overall, it is hypothesized that conflicts are more common between full- than half-siblings. This study tested this assumption using the British Millennium Cohort Study ( n =7527 children at age 11). Conflicts were measured as children’s reports of how much siblings picked on and hurt each other. Households with full-siblings only, maternal half-siblings only, and both full- and maternal half-siblings were compared. The results show that children who were living with only their full-siblings were more likely to experience sibling conflicts compared with children living with their maternal half-siblings only. This was the case also after controlling for several potentially confounding variables. The results suggest that differential access to parental resources of available biological and step-parents may explain the higher amount of sibling conflict between full- compared with maternal half-siblings.
Chapter
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Our siblings can be our closest allies and yet are often our first rivals. What factors influence the nature of these relationships, and are there certain aspects that make our sib-lings more likely to be a source of conflict rather than solidar-ity? From an adaptationist perspective, sibling conflict should vary in frequency and intensity as a function of degree of relatedness. For example, conflict should be most frequent and intense between non-biological and step-siblings while conflict between full biological siblings should be least frequent and intense with half-sibling conflict being of an intermediate degree. This study examines levels of sibling conflict as a function of sex of participant, sex of sibling, degree of relatedness, and length of co-residence as well as self-reported sources of conflict. Results indicate that genetic relatedness does influence the frequency and intensity of conflict, though the most intense conflict was between non-biological siblings and the least was between half-siblings.
Chapter
Kinship has been a central organizing principle in evolutionary explorations of social behavior ever since Hamilton (J Theor Biol 7:1–52, 1964) extended the concept of Darwinian fitness benefits to include actions that benefit not only own offspring but also collateral kin. This insight into humans as nepotistic strategists has fueled an extensive literature on the adaptations that make up the repertoire that is our family psychology from those that shape mothers’ and fathers’ substantial investment in offspring, to parent–offspring conflict over the allocation of investment, to sibling conflict and cooperation, and the valuable investment that some grandparents make to the survival and success of their grandchildren. No understanding of social behavior can be complete without understanding where it all starts: with the families we grow up in.
Chapter
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Sibling competition is widespread in the natural world, and sometimes ends in siblicide. Birth order among siblings affects the outcome of such contests, because it is a proxy for disparities in age, size, power, and opportunity. In humans, birth order combines with the prolonged period of childhood dependence on parents to promote differences in parental investment. In addition, siblings often occupy different niches within the family and employ differing tactics in competition with one another. These disparate experiences influence personality, sentiments about the family, patterns of motivation, and attitudes more generally. Birth order has also been implicated in support for, and opposition to, radical social and scientific revolutions. Although the persistence of birth-order effects in adulthood is well established by numerous studies, the extent and magnitude of these effects remains controversial.
Chapter
Summary of research on the effects of birth order
Chapter
By influencing the strategies that siblings develop in competition for parental favor, birth order fosters differences in personality that in turn correlate with differences in creative achievement. The nature of the relationship between birth order and creativity has long been controversial owing to the failure of researchers to specify exactly what kinds of creativity they have in mind. Firstborns and laterborns do not appear to differ in overall levels of creativity, but they do differ in the ways by which they attain creative distinction.
Chapter
From the parental perspective, each individual's overall reproductive effort is a combination of mating effort and parental effort or investment. There are numerous factors that can have an impact on the amount of parental resources invested in any particular child. The potential for conflict exists between parents over how much parental investment each should give to their shared genetic offspring. Offspring compete amongst themselves for access to parental resources. Parent-offspring conflict can arise because some actions that advance the fitness of an offspring can potentially reduce the lifetime success of the parent and just as some actions that benefit parental fitness can reduce the lifetime fitness of a particular offspring. Natural selection has shaped strategies for sibling competition just as it shaped mechanisms for discriminative parental solicitude. Many factors play a role in the approach individual siblings may take, but two are of particular interest: birth order and birth spacing.
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Women’s marital surname change was investigated as a potential marital commitment signal, and strategy for enhancing investment from in-laws and husband. Hyphenating or keeping premarital surname for all U.S. destination brides marrying in Hawai'i in 2010 was significantly correlated with a women’s income measure (r = .78, p < .000) and with the analogous statistic for men (r = .64, p < .000), by bride’s state of residence. The women’s measure, only, remained significant under regression of both predictors. The interaction of state Gini and the women’s income measure in a regression including the interaction components as predictors was positively predictive (adjusted-R2= .57). None of several other predictors suggested by previous research or related to Gini or income were significant under regression, alongside the women’s income measure. The older the bride, from any jurisdiction, marrying in Hawai'i in 2010, the more likely to hyphenate/keep premarital surname (χ2(1) for linear trend = 1754.65, p < .000). Among all opposite-sex couples (N = 167 couples) divorcing in a Canadian county in an 8-month period, 2013-2014, marriages the women in which underwent marital surname change lasted 60% longer, controlling for wife’s age at the time of marriage. When the woman’s marital surname change/retention was used as a regression predictor of number of children of the marriage alongside marriage duration in years, only the latter was predictive. Brides-to-be from across especially western and central Canada (N = 184) were surveyed as to marital surname hyphenation/retention versus change (DV 1), and attitude towards such retention in general (DV 2). Among women engaged to men, the hypothesized predictors of income and number of future children desired were positively predictive of marital surname retention/hyphenation under univariate analysis. Under multiple regression analysis using these and other predictors from the literature also found to be predictive of this DV under univariate analysis, only some of these other predictors were predictive. An EFA factor score calculated from several attitude items concerning in-laws, conceptualizable as In-law avoidance motivation, was not predictive of general attitude toward or actual retention/hyphenation, contrary to prediction.
Thesis
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132 female, never-married, undergraduate psychology students were surveyed regarding attitudes concerning taking their husband 's surname upon marriage . It was hypothesized that approval of such a surname change would be associated with their views on (I) resource transfer from, and involvement with , in -laws, and (2) the importance of high resource potential in a candidate husband. Lesser approval of taking husband 's surname was significantly predicted under OLS regression by desire for in -laws to be uninvolved with the newlywed couple and their children. The importance of resource holding potential in a candidate husband was a marginally significant predictor, moderated by the women 's own mothers' taking of their fathers' surnames, as well as by how emotionally close these women were to their fathers. Retaining or hyphenating one 's pre-marital surname among brides marrying in Hawaii in 2006, was significant y correlated with average in come of women and the average income of men in the bride's state of residence, with only that of women, however, being a marginally-significant predictor where both were used as regression predictors of retention or hyphenation. Older brides were more likely to hyphenate or retain their pre-marital surnames upon marriage in Hawaii in 2006.
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Introduction: This paper focuses on the empirical study of correlation between the sibling position and the extremist attitudes of young people. The purpose of this study is to analyze the specifics extremist attitudes of young men and women depending on their birth order. Materials and Methods: The participants of the study were 377 subjects (aged between 14 and 30 years, 176 male subjects and 201 female subjects). 100 participants are the only children, 117 ones are the first-borns, 53 ones are middle children and 106 are later-borns. Extremist attitudes of the subjects were identified using K. V. Zlokazov 's methodology of studying extremist-destructive attitudes. This technique allows us to reveal the level of authoritarianism, the manifestation of nationalistic, fanatical and xenophobic attitudes. According to E.A. Pain and S.A. Prostakov's methodology, the subjects were supposed to choose a political slogan characteristic of an extremist trend or refuse to choose. Results: As a result of the research, a correlation was found between extremist attitudes of youth and the sibling position in the family (both gender-specific and non-gender-specific). Young males in comparison with young females are characterized by a higher level of extremism (manifested in a higher level of nationalism and xenophobia), more often identify themselves with one or another political movement. The only children in the family are characterized by a higher level of nationalist attitudes, less adhering to left-wing views. A higher level of fanaticism is revealed in only children girls and laterborns boys in the family. A higher level of xenophobia was found in single boys in the family. Conclusions: A group of only children in the family of boys entered the risk group for the formation of extremist behavior. They have a much higher degree of xenophobic attitudes, and they often choose nationalist slogans in comparison with other groups of subjects. The results of this study can be taken into account in working with young people to prevent extremist behavior.
Chapter
The relationships between birth order, personality, and behavior are ones that have received a great deal of attention from researchers. Much recent progress into understanding the impact birth order has in shaping personality and behavior has been made by taking a Darwinian family niche perspective on birth order. There are a number of documented birth order patterns in the big five personality traits as well as behavioral aspects such as risk-taking, interactions with family and friends, cooperativeness, and workplace choice and relationships. Methodological issues have sometimes led to inconsistent results, but overall, the evidence suggests that birth order does indeed have a significant impact.
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The article analyses theoretical approaches and empirical research of the influence of the children’s birth order in the family on their intellectual and creative abilities, achievements in education, personality traits, behaviors and social preferences. It is shown that the results of the studies vary depending on the method of data analysis - the effect of decreasing intelligence while increasing the birth sequence number detected when comparing indicators of large numbers of children with different birth order from different families, and generally not detectable in intra-family analysis data. To explain the differences obtained the authors used three basic theoretical models: a model of merge, the model of resource depletion and impurity model. Due to differences in birth order personality traits have more pronounced differences in the cognitive sphere. Research confirms that according to the results of the personal questionnaire «Big five» firstborns display more pronounced «honesty», and younger children-«kindness» and «openness» to experience. Individual work on features of social interaction of senior and subsequent children demonstrated a great ability of younger children to cooperation. Despite the fact that the prognostic significance of identified effects in large samples is not as great as in individual families, results may have practical significance for the pedagogical and psychological work with children.
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Предлагаемая монография посвящена вопросам развития границ Я как предпосылок диспозициональной суверенности в детском возрасте и возможностям использования этой черты личности в ходе взаимодействия с «большим социумом». Выделены качества и функции границ Я; показано, что в детстве их развитие происходит в нескольких направлениях – от физических к символическим, от защиты собственной эмпирической личности к уважению границ других людей. Показана роль статуса сиблинга и психофизиологических предпосылок в развитии диспозициональной суверенности. Показано, с какими социальными верованиями и особенностями культуры она связана. Монография может быть полезна исследователям, практикам и всем интересующимся развитием личности.
Article
This study investigated the relationships between birth order, personality, academic performance, and parent-child relationship amongst 120 college students from the Klang Valley. The sample constituted of 30 firstborns, 30 middleborns, 30 lastborns, and 30 only children with a mean age of 20.0 years (SD= 1.85). Instruments used in this study were Ten Item Personality Inventory (TIPI) and Parent-Child Relationship Survey (PCRS). Results indicated that participants of different birth orders did not differ significantly in terms of their personality, academic performance and parent-child relationship. Furthermore, this study also found no relationship between parent-child relationship and academic performance. However, extraversion was found to be correlated positively with academic performance. Besides, this study also indicated that parent-child relationship did correlate with children's openness to experience, emotional stability, and conscientiousness. This implies the importance of a match between one's personality trait and field of study, as well as the importance of good parenting practices.
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Kin terms such as "brothers," "sisters," and "motherland" are frequently used in both political and patriotic speech. Johnson (1986, 1987) has argued that this use of kin terms in patriotic or rhetorical speech can be predicted on the basis of evolutionary psychology. He has suggested that the human inclination toward nepotistic behavior can be called forth by the successful manipulation of kin terminology. In this study, two hypotheses were examined concerning the evocativeness of kin terminology in political speech and the influence of birth order on the effectiveness of such terminology. The first hypothesis was that kin terms would be more effective than more distant relationship terms (like "friend") in evoking a positive response. Kin terms elevated agreement with the views expressed in the speech that the subjects heard. The second hypothesis, that middleborns would be less likely to respond to such kin term usage than first or lastborns, was based on previous work on birth order and family relations (Salmon and Daly, in press). And in fact, middleborns were less likely to be influenced by the use of kin terms than first or lastborns in this study.
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When parent-offspring relations in sexually reproducing species are viewed from the standpoint of the offspring as well as the parent, conflict is seen to be an expected feature of such relations. In particular, parent and offspring are expected to disagree over how long the period of parental investment should last, over the amount of parental investment that should be given, and over the altruistic and egoistic tendencies of the offspring as these tendencies affect other relatives. In addition, under certain conditions parents and offspring are expected to disagree over the preferred sex of the potential offspring. In general, parent-offspring conflict is expected to increase during the period of parental care, and offspring are expected to employ psychological weapons in order to compete with their parents. Detailed data on mother-offspring relations in mammals are consistent with the arguments presented. Conflict in some species, including the human species, is expected to extend to the adult reproductive role of the offspring: under certain conditions parents are expected to attempt to mold an offspring, against its better interests, into a permanent nonreproductive.
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Theory and data suggest that a male in good condition at the end of the period of parental investment is expected to outreproduce a sister in similar condition, while she is expected to outreproduce him if both are in poor condition. Accordingly, natural selection should favor parental ability to adjust the sex ratio of offspring produced according to parental ability to invest. Data from mammals support the model: As maternal condition declines, the adult female tends to produce a lower ratio of males to females.
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Responses of 657 college students of both sexes to questions about family relationships showed significant differences between 185 middleborn children and 472 children in other birth order positions. These differences support findings of prior studies of adolescents and children, suggesting that middleborns feel less parental support than other children. A significantly higher percent of middleborn students indicated that they received no parental assistance with their college expenses. Middleborns were less likely to indicate having a close relationship with their parents, less likely to indicate frequent telephone calls home, and more likely to indicate brother or sister (rather than parent) as having difficulty adjusting to their absence.
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The abstract for this document is available on CSA Illumina.To view the Abstract, click the Abstract button above the document title.
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This study examines the effect of the sibling structures of number and spacing, sex composition, and birth order on adolescents' perceptions of the power and support dimensions of parental behavior. These sibling structures are conceptualized as dimensions on a hypothetical sibling time line, including number of siblings and the way in which they are arranged in time, i.e., the spacing and birth order. Data were obtained from a secondary analysis of a national sample of over 1,700 adolescent males. The results suggest that research focusing on birth order as an explanatory variable must control for number of siblings, spacing, and sex composition of siblings; studies examining family size must control for sibling spacing, birth order, and sex composition. In addition a curvilinear relationship was found between perceived parent behaviors and wider spacing between siblings. The "best" spacings are the widest (five years) and the narrowest (one year or less), with spacings of two and three years being the most negative. Most of the power in the curvilinear relationship obtains with male respondents whose closest sibling is male. Males whose closest sibling is female, however, view their parents as more punitive. Both empirical and practical implications of these findings are discussed.
Article
This study examines the self-esteem of middleborns compared with firstborns and lastborns. While most of the birth-order research concentrates on comparing firstborns with a general category of "laterborns," the present research emphasizes an empirical and conceptual distinction for middleborns. The number, spacing, and sex of siblings of the middleborn are also closely examined. Data were obtained from a secondary analysis of a national sample of over 2,200 adolescent males. The results suggest that middleborns have a significantly lower self-esteem than firstborns and lastborns and that the self-esteem of middleborns is significantly lower when the average spacing of their immediately adjacent siblings is two years compared with one year. Self-esteem of the middleborn male is significantly enhanced when his siblings are all female than when they are all male or mixed gender. The findings are explained according to a uniqueness theory, which suggests that firstborns and lastborns enjoy an inherent uniqueness in their birth order which facilitates status, recognition, and attention by parents and other siblings. There is no inherent uniqueness in the position of middleborn child, whose role in the family is consequently less well defined. This is reflected in the middleborn's overall self-assessment.
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Why are individuals from the same family often no more similar in personality than those from different families? Why, within the same family, do some children conform to authority whereas others rebel? The family, it turns out, is not a "shared environment" but rather a set of niches that provide siblings with different outlooks. At the heart of this pioneering inquiry into human development is a fundamental insight: that the personalities of siblings vary because they adopt different strategies in the universal quest for parental favor. Frank J. Sulloway's most important finding is that eldest children identify with parents and authority, and support the status quo, whereas younger children rebel against it. Drawing on the work of Darwin and the new science of evolutionary psychology, he transforms our understanding of personality development and its origins in family dynamics.
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Popular and professional wisdom argues that rapid social change results in a search for genealogical roots. Indeed, interest in genealogy followed the industrial revolution of the nineteeth century, World War I, and World War I. The same notion can be applied to the individual level. Individuals who experience social dislocation such as geographical or social class mobility, it is posited, would be more interested in genealogy than those who do not experience such changes. Family size or changes in family size from one generation to another and birth order may also be related to interest in the study of one's genealogical roots. Finally, ethnicity may be related to genealogical interest. To test these hypotheses, a sample of genealogists and a sample of other hobbyists were compared. Information about their geographical and social backgrounds and a variety of other topics was obtained in a survey. In general, the social dislocation hypotheses are not supported. Stayers rather than movers, and older immigrant groups rather than new immigrant groups show interest in their genealogical roots.
Article
Sex differences in the salience and meaning of kin relations for contemporary Canadians were examined in two studies. In study 1, 24 opposite-sex adult sibling pairs were asked to reconstruct their kindreds as fully as possible, following a computerized menu. Sisters almost invariably recalled more relatives than did their brothers, especially living and matrilateral relatives. In study 2, a questionnaire administered to 150 female and 150 male undergraduates explored the relevance of kinship to characterizations of the self (“Who are you?”) and to nominations of one's closest social relationships. Women were much more likely than men to refer to their kinship statuses in characterizing themselves (I am a daughter, a sister, etc.), whereas 28% of men and only 8% of women mentioned their surnames (I am a Smith, Jones, etc.). Women and men were about equally likely to name a relative, as opposed to a mate or friend, as the person to whom they feel closest, but women more often nominated a parent (especially mother) and men a sibling (especially an older sister). These sex differences are discussed in relation to possible differences in how women and men make use of family ties.
Article
Nest and offspring defence by birds can be treated as an optimization problem wherein fitness benefits are determined by the survival of the current brood and fitness costs depend upon the probability that the parent will survive to breed again. At the optimal intensity of defence, net fitness benefits are maximized. Most research has focused on seasonal patterns of nest defence to test the prediction that intensity of nest defence should increase through the nesting cycle either because renesting potential declines or because the probability of offspring survival increases rapidly relative to that of the parents. Intensity of nest defence is predicted to increase with parental experience and confidence of parenthood; offspring number, quality and vulnerability; and nest accessibility and conspicuousness. The response of parents is also expected to vary with the relative armament and mobility of parent and predator and the relative roles of the parents in caring for their offspring. -from Authors
Article
Measures of adult feeding and foraging behaviour in the California gull, Larus californicus, were related to the growth of their offspring. Offspring showed significantly higher growth when average feeding interval, a measure of the time interval between feedings, and feeding latency following foraging decreased. The amount of time parents foraged was positively related to offspring growth and negatively correlated with average feeding interval. Either (1) increased foraging efficiency with parental age, or (2) increased reproductive effort with age, could explain age-related differences in patterns of feeding behaviour and their impact on offspring growth. However, data on foraging time support only the hypothesis of increased reproductive effort with parental age.
Article
Three hundred randomly selected, white, middle-class Los Angeles women were interviewed to determine variations in patterns of helping among kin versus nonkin. Specific predictions arising out of the evolutionary theories of kin selection and reciprocal altruism were supported: helping among friends was more likely to be reciprocal than helping among kin, closer kin were more likely sources of help than were more distant kin; among kin, helping was an increasing function of the recipient's expected reproductive potential; and the larger the amount of help given, the more likely it was to come from kin. The data suggest that the effects of variables such as kinship, age, wealth, sex, and expected reproductive potential are small but persistent, and hence potentially of great functional significance when present generation after generation. Subjects reported seeking help from individuals who had been sources of help in the past more often than from individuals who owed them help. Hints of deception or self-deception are present: Subjects reported giving more than they received and paying back more often than they were paid back.
Article
One of the most important findings that has emerged from human behavioral genetics involves the environment rather than heredity, providing the best available evidence for the importance of environmental influences on personality, psychopathology, and cognition. The research also converges on the remarkable conclusion that these environmental influences make two children in the same family as different from one another as are pairs of children selected randomly from the population. The theme of the target article is that environmental differences between children in the same family (called “nonshared environment”) represent the major source of environmental variance for personality, psychopathology, and cognitive abilities. One example of the evidence that supports this conclusion involves correlations for pairs of adopted children reared in the same family from early in life. Because these children share family environment but not heredity, their correlation directly estimates the importance of shared family environment. For most psychological characteristics, correlations for adoptive “siblings” hover near zero, which implies that the relevant environmental influences are not shared by children in the same family. Although it has been thought that cognitive abilities represent an exception to this rule, recent data suggest that environmental variance that affects IQ is also of the nonshared variety after adolescence. The article has three goals: (1) To describe quantitative genetic methods and research that lead to the conclusion that nonshared environment is responsible for most environmental variation relevant to psychological development, (2) to discuss specific nonshared environmental influences that have been studied to date, and (3) to consider relationships between nonshared environmental influences and behavioral differences between children in the same family. The reason for presenting this article in BBS is to draw attention to the far-reaching implications of finding that psychologically relevant environmental influences make children in a family different from, not similar to, one another.
Article
This paper investigates the possibility that birth order affects the degree to which individuals attain higher status. Humans give birth to a variable number of (usually) single offspring spaced one to many years apart, and continue to maintain contact with them for extended periods of time. The continued presence of older siblings, and arrival of younger ones, means that each child is reared in a different family environment. Research findings from the field of behavior genetics suggest that these differences have a significant impact on the development of individual differences between children in the same family. Although no two families are likely to be exactly the same, factors such as birth order remain constant across them, and may have similar influences. The present study examines the relationships between birth order, sibship size, and several variables thought to index future status attainment (status striving) in a random sample of Canadians. Firstborn children appear to be more status oriented than lastborns, and this effect is mediated by sibship size. While firstborn children are unaffected by the number of younger siblings they have, the status ambitions of youngest children decrease the more older siblings they have. Birth order effects on status attainment are not as strong as they are on status ambitions.
Article
Mother-infant interaction was assessed on 32 first- and second-born siblings when each was 3 months old. Data were colleted during 2 6-hour naturalistic home observations using a modified time-sampling technique. The sample consisted of 4 equal-size subgroups of same and opposite sex sibling pairs. Results suggested that interaction between a mother and her infant varied depending on the birth order and gender of the infant. Mothers spent significantly less time in social, affectionate, and caretaking interaction (except for feeding activities) with their second borns than they had with their firstborns; this difference was greater if the second born was female. Certain patterns of maternal behaviors appeared to be stable from one sibling to the other. Different types of interaction between the mothers and their younger infants were related to attention-seeking behavior in the firstborn male and female siblings.
Article
A discrimination theory of selective perception was used to predict that a given trait would be spontaneously salient in a person's self-concept to the exten that this trait was distinctive for the person within her or his social groups. Sixth-grade students' general and physical spontaneous self-concepts were elicited in their classroom settings. The distinctiveness within the classroom of each student's characteristics on each of a variety of dimensions was determined, and it was found that in a majority of cases the dimension was significantly more salient in the spontaneous self-concepts of those students whose characteristic on thedimension was more distinctive. Also reported are incidental findings which include a description of the contents of spontaneous self-comcepts as well as determinants of their length and of the spontaneous mention of one's sex as part of one's self-concept.
A sociobiological analysis of human infanticide
  • M Daly
Daly, M., and Wilson, M. A sociobiological analysis of human infanticide. In Infanticide: Comparative and Evolutionary Perspectives, G. Hausfater and S.B. Hrdy (Eds.). New York: Aldine, 1984, pp. 487-502.
Ayoreo infanticide: a case study
  • P E Bugos
  • L M Mccarthy
Bugos, P.E., and McCarthy, L.M. Ayoreo infanticide: a case study. In Infanticide: Comparative and Evolutionary Perspectives, G. Hausfater and S. B. Hrdy (Eds.). New York: Aldine, 1984, pp. 503-520.
Manual for the Twenty Statements Problem. Kansas City, MO: Greater Kansas City Mental Health Foundation Department of Research
  • W S Hartley
Hartley, W.S. Manual for the Twenty Statements Problem. Kansas City, MO: Greater Kansas City Mental Health Foundation Department of Research, 1970.
The Psychology of Affiliation
  • S Schachter
Schachter, S. The Psychology of Affiliation. Stanford, CA: Stanford University Press, 1959.
Binbrook Historical Society. The History and Heritage of Binbrook
  • District Antler
  • History Committee
Antler and District History Committee. Footprints in the Sands of Time. 1983. Arnstein, H.S. Brothers and Sisters/Sisters and Brothers. New York: Dutton, 1978. Binbrook Historical Society. The History and Heritage of Binbrook. 1979.
Greater Kansas City Mental Health Foundation Department of Research
  • W S Hartley
Hartley, W.S. Manual for the Twenty Statements Problem. Kansas City, MO: Greater Kansas City Mental Health Foundation Department of Research, 1970.
The neglected bith order: middleborns
  • J S Kidwell
Kidwell, J.S. The neglected bith order: middleborns. Journal of Marriage & the Family 44:225-235, 1982.