The Parasite-Stress Theory of Values and Sociality: Infectious Disease, History and Human Values Worldwide
Abstract
This book develops and tests an ecological and evolutionary theory of the causes of human values-the core beliefs that guide people's cognition and behavior-and their variation across time and space around the world. We call this theory the parasite-stress theory of values or the parasite-stress theory of sociality. The evidence we present in our book indicates that both a wide span of human affairs and major aspects of human cultural diversity can be understood in light of variable parasite (infectious disease) stress and the range of value systems evoked by variable parasite stress. The same evidence supports the hypothesis that people have psychological adaptations that function to adopt values dependent upon local infectious-disease adversity. The authors have identified key variables, variation in infectious disease adversity and in the core values it evokes, for understanding these topics and in novel and encompassing ways. Although the human species is the focus in the book, evidence presented in the book shows that the parasite-stress theory of sociality informs other topics in ecology and evolutionary biology such as variable family organization and speciation processes and biological diversity in general in non-human animals. © Springer International Publishing Switzerland 2014. All rights are reserved.
Chapters (14)
The particularistic method of cultural analysis relies on a region’s specific cultural history to explain why the region’s culture is the way it is. The particularistic method assumes incorrectly the popular view that culture is passively accepted by future generations. A very different perspective on culture sees people as evolved cultural strategists who accept, reject, and modify values and other cultural items using psychological adaptation that is functionally designed for this purpose. The empirical findings throughout our book strongly support the strategic perspective on enculturation. We hypothesize that the particularistic interpretation of enculturation derives from a value system that prioritizes tradition and interdependent self-concept—i.e., the value system of collectivism/conservatism. We introduce the parasite-stress theory of values/sociality, which is the general theory used throughout the book to analyze enculturation, cultural diversity and sociality, and to unify in shared proximate and evolutionary causation the wide range of topics treated in the book. According to this theory, the level of infectious-disease stress in a region causes people’s values—low parasite stress evokes liberalism/individualism and high parasite stress evokes conservatism/collectivism. Although scientific discoveries about values cannot identify moral or immoral activity, they may allow achievement of whatever moral goals are identified by people. The book’s empirical findings, discovered by applying the parasite-stress theory of values, indicate that democratic or equalitarian values can be promoted by reducing infectious disease in a region, whereas undemocratic values can be promoted by increasing infectious disease. Brief overviews of the subsequent 13 chapters of the book are provided.
We treat the scientific procedures and assumptions used throughout the book. The scholarly study of aesthetic judgments, including those about the attractiveness/unattractiveness of values, initially arose as a branch of philosophy. We criticize the philosophical method as a way of knowing the causes of values. The scientific method, developed in part by Francis Bacon, replaced the philosophical method and then became, and remains, the sole way of knowing the causes of natural things, including the causes of morals or values. Darwin’s method of historical science importantly extended the scientific method to causes in the deep-time past. We also treat the fundamentals common to all scientific investigation. Additionally, we discuss the salience of individual-level selection in causing evolution, including in the creation of all adaptations of social life. Moreover, we distinguish proximate and ultimate (evolutionary) causation and elaborate on the topic of enculturation that was introduced in Chap. 1. We discuss and resolve misunderstandings of comparative methodology, which is the method we emphasize throughout in testing hypotheses across regions. Lastly, we comment on ideological criticisms of evolutionary theory applied to human affairs.
The parasite-stress theory of values/sociality is presented in detail. Humans have two immune systems: the classical physiological, cellular, and tissue-based defense system and the behavioral immune system. Only recently has the latter been investigated in detail; it is comprised of two parts: (a) psychology and behavior for infectious-disease avoidance and (b) psychology and behavior for managing the fitness-reducing effects of parasitic infection. In this book, our focus is on the behavioral immune system. This immune system is comprised of the adaptations of philopatry, xenophobia, and ethnocentrism, which are the basic features of assortative sociality. In subsequent chapters, we show that the components of assortative sociality/behavioral immunity increase with increasing parasite stress across regions, as predicted by the parasite-stress theory of values. The three components of assortative sociality—limited dispersal, ethnocentrism, and xenophobia—also fractionate cultures and thereby contribute to the genesis of new cultures. Thus, the parasite-stress theory includes a hypothesis about the origin of cultural or ethnic diversity. The parasite-stress theory of sociality also includes an important engine of speciation. In Chap. 13, we present empirical support for the ethnogenesis and speciation aspects of the parasite-stress theory of sociality. The early published research findings inspired by the parasite-stress theory of sociality are reviewed briefly. This theory has produced numerous new discoveries and new interpretations of previously described findings.
The large scientific literature on human values produced prior to the recent publication of the parasite-stress theory of values is reviewed and analyzed. The major causal frameworks in that literature—climate and wealth—are not alternatives to the parasite stress of values—they are complementary, proximate causes of values. The parasite-stress theory of values is a synthetic theory of values encompassing both proximate and evolutionary causation of values. Traditional research effort in the investigation of values has focused on the unidimensional value system of collectivism–individualism because of its ability to capture differences in values across regions. The values that correlate with collectivism and individualism are reviewed. The great similarity of the values dimension of collectivism–individualism to the values dimension of conservatism–liberalism is documented. Additional studies are discussed that reported differences between conservatives and liberals, but did not measure collectivism–individualism per se. These additional studies also support the high correspondence between collectivism–individualism and conservatism–liberalism. Conservative/collectivist values and liberal/individualist values differ in many ways that correspond to differences in authoritarianism, social prejudices, equalitarianism, social hierarchy, self-concept, reasoning style, linguistic behavior, personality, religiosity, the structure of social networks, in-group and out-group transactions, economics, governmental systems, dispersal, family relationships, violence, warfare, adherence to tradition, norm adherence, honor ideology, sexual behavior, and marriage. According to the parasite-stress theory of values, the form that each of these features takes in a region is caused proximately by the region’s level of parasite adversity and associated evoked values.
As predicted by the parasite-stress theory of values, variation in parasite stress correlated with collectivism–individualism across nations, USA states, and indigenous societies. In regions with high adversity of infectious diseases, human cultures are characterized by high collectivism, whereas in regions of low parasite stress cultures are highly individualistic. The prediction from the parasite-stress theory of values that infectious disease transmissible among humans (nonzoonotics) will be more important in predicting collectivism–individualism than those that humans can contract only from nonhuman animals (zoonotics) was supported. Evidence in human movement patterns for nations, states of the USA, and indigenous societies supports the hypothesis that the absence of dispersal (high philopatry) is a defense against contact with novel parasites in out-groups and their habitats. We show that human cultures with high degrees of collectivism have high degrees of cooperative breeding, and propose that the parasite-stress theory of sociality offers a general theory of family structure across humans as well as nonhuman animal taxa. We propose that a major context for the evolution of human reciprocity was in gaining benefits from out-group interactions during periods of relatively low disease threat. The parasite-stress theory of values offers a novel perspective to explain the evolution of reciprocity and human unique cognitive abilities. The parasite-stress theory suggests useful new research directions for the study of the demographic transition, patriotism, xenophobia, ethnocentrism, and moral foundations theory. We include discussion of ecological correlations and the ecological fallacy. The fact that all scientific findings are correlational is explained.
The parasite theory of sexual selection, originated by Hamilton and Zuk in 1982, is a subcategory of the more general and encompassing parasite-stress theory of sociality. Across indigenous societies, parasite-stress is correlated positively with the degree of polygyny. This is expected because high parasite stress generates high variation in the phenotypic and genetic quality of men, which then makes polygynous marriage adaptive for women, even though they must share a husband’s resources with harem wives. Research shows that, as parasite stress increases or as a person’s concern about infectious diseases increases, so does the value of obtaining a physically attractive mate (high genetic quality defends against parasites); evidence suggests that the importance of having such a mate is correlated positively with conservatism across cultures and people. Parasite stress predicts positively women’s sexual restrictiveness across countries. Cross-national evidence indicates that women’s sexual liberation from traditional values of sexual restriction is a component of overall liberalization of values. As predicted by the parasite-stress theory of values, as parasite adversity increases across regions, people engage in increased marital inbreeding, both cross-nationally and across indigenous cultures. Men’s xenophobia toward out-group men is mediated by concern about contracting novel parasites as well as by viewing out-group men as sexual competitors. As predicted by the parasite-stress theory of values, the practice of lynching black men engaged in by white racists is related positively to parasite stress and collectivism across US states. Research indicates sophisticated functional design of men’s sexual disgust. Like other kinds of disgust, sexual disgust functions, at least in part, to protect against contagion risk but is moderated when men’s mating opportunities arise.
Evidence across countries indicates that as parasite stress increases, so does introversion and closed-mindedness to new experiences. Also, the number of nonzoonotic human infectious diseases predicted significantly cross-national differences in the personality traits; the number of zoonotic parasitic diseases did so only marginally at best. A follow-up study, presented for the first time in our book and involving nonzoonotic versus zoonotic disease severity (rather than disease number), provided results similar to those based on number of diseases. Thus, cross-national variation in the personality dimensions appears to be attributable almost entirely to the adversity of nonzoonotic diseases, as expected from the parasite-stress theory of values. Other evidence shows that when people were primed with stimuli simulating a contagion threat, they shifted immediately toward an avoidance of interaction with people: they were less agreeable, less open to experience, less extraverted, and reacted with avoidant arm movements to strangers. Other research has shown that people’s classical immune system is activated by the parasite-salient cues that cause shifts in personality. Many important aspects of personality are features of the behavioral immune system. Future research in human personality will benefit from consideration of the parasite-stress theory of values and its relationship to each of the big five personality factors. Future research in personalities of nonhuman animals may benefit from studying the personality traits as traits of behavioral immunity. The research overall indicates that the parasite-stress theory of sociality may provide a new and general theory of personality.
The parasite-stress theory of values offers new perspectives and research directions for the study of interpersonal violence, and provides a theoretical and empirically synthetic foundation that promises to be more encompassing than those used by previous interpersonal-violence researchers. Evidence indicates that parasite stress may be the strongest predictor of rates of interpersonal violence to date. We argue that collectivist values evoked by high parasite stress account for the culture of honor and cause adult-on-adult interpersonal violence. Across the US states, parasite stress and collectivism each positively predict rates of men’s and women’s slaying of a romantic partner, as well as the rate of male-honor homicide and of felony-related homicide. Parasite stress and collectivism also positively predict international rates of overall homicide. Child maltreatment by caretakers is caused, in part, by divestment in offspring of low phenotypic quality, and high parasite stress produces more such offspring than low parasite stress. Rates of child maltreatment across the US states are predicted positively by parasite stress. Infectious diseases that can be transmitted human-to-human (nonzoonotic diseases) are stronger predictors of interpersonal violence than are zoonotic human diseases. The parasite-stress theory of values may be useful in reducing rates of interpersonal violence across the world and informs the other major category of violence, intergroup violence, or warfare (see Chap. 12).
Researchers have studied extensively regional variation in religious commitment and participation (religiosity). Such research, whether based on economic theory or evolutionary theory, emphasizes the high costs to individuals of religiosity. We have offered a new hypothesis of religiosity based on the parasite-stress theory of values. It relies on the theory of honest signaling in biology. We propose that religiosity is one important way that people engage in and display their in-group allegiance and boundary in order to avoid and manage infectious disease threats. In support of this, we provide evidence that religiosity is an aspect of in-group assortative sociality—and therefore an aspect of the behavioral immune system—and that religiosity correlates positively with parasite adversity, both cross-nationally and across states of the USA. We suggest additional tests of the parasite-stress theory’s application to religiosity. Other hypotheses of religiosity in the literature are evaluated. The parasite-stress theory of values appears to best account for religiosity and its diversity across regions. Our findings on religiosity have implications for a multitude of other areas of research such as secularization, health, ontogeny of religious values, life history, and geographical expansions of religion.
The countries of the world vary in their position along the autocracy–democracy continuum of governance. We hypothesize that the variation in values pertaining to the autocracy–democracy dimension arises fundamentally out of human species-typical psychological adaptation that manifests contingently, producing values and associated behaviors that functioned adaptively in human evolutionary history to cope with local levels of infectious diseases. We test this parasite-stress hypothesis of democratization using data measuring democratization, collectivism–individualism, gender egalitarianism, property rights, sexual restrictiveness, and parasite adversity across many countries of the world. We show that, as the hypothesis predicts, collectivism (hence, conservatism), autocracy, women’s subordination relative to men’s status, and women’s sexual restrictiveness are features that positively covary, and correspond with high prevalence of infectious disease. The psychology of xenophobia, ethnocentrism, traditionalism, and authoritarianism links these features to avoidance and management of parasites. Also as predicted, we show that the antipoles of each of the above features—individualism (hence, liberalism), democracy, anti-authoritarianism, and women’s rights, freedom and increased participation in casual sex—are a positively covarying set of features in countries with relatively low parasite stress. We discuss evidence that the generation and diffusion of innovations (in thought, action, and technology), which is an important component of democratization, is causally related to low parasite stress and its evoked values, particularly liberalism and associated openness. Other evidence supporting the parasite-stress hypothesis of democratization is discussed: the geographical location of the earliest democratic governments, patterns of censorship and transparency in the media across nations, patterns of autocracy across indigenous societies, and physical-attractiveness prejudices of voters across US congressional districts.
The parasite‐stress hypothesis of economics proposes that variation in infectious disease across regions causes variation in economic productivity by three proximate causes. (1) Infectious diseases cause morbidity, reducing people’s capability to produce. (2) Parasite stress evokes people’s values, which, in turn, cause regional economic parameters. For example, as parasite stress increases, regions become increasingly collectivistic. Collectivism causes parochial economics, political corruption, autocratic governance, and reduced innovativeness and diffusion of innovations. These effects stifle economic productivity of a region. In contrast, individualism causes willingness to transact with a diversity of people, creating broad economies and interregional sharing of ideas and products, increased innovativeness, governmental transparency, and democracy. These effects promote economic prosperity and equality. (3) Infectious disease limits cognitive ability, which reduces innovativeness and thus economic well-being in a region. Evidence supporting this framework is both diverse and copious. We discuss the established negative relationships between two important economic indicators, GDP per capita and Gini, and parasite stress and collectivism across the countries of the world. Studies also have confirmed the negative relationship between the diffusion of various innovations and parasite stress and collectivism across countries and US states. Evidence shows that even the routine purchases of people at supermarkets are consistent with the parasite-stress theory of values. We also discuss research indicating that parasite-stress variation across the globe affected wealth of regions as far back as 1500 ad. Cognitive ability is correlated negatively with parasite stress and collectivism both across countries and US states.
This chapter documents the applicability of the parasite-stress theory of values to the frequencies of occurrences of the major types of within-nation intergroup conflict across contemporary countries: civil wars, non-state wars (intrastate wars in which warring groups do not include the government of the state), and coups and revolutions. Collectivist values of people promote interdependence with, and loyalty toward, in-group members (ethnocentrism) and goals, and antagonism toward out-group members (xenophobia) and goals. Host–parasite antagonistic coevolutionary races produce variation among regions in the specificity of immune defenses and of parasites. According to the parasite-stress theory, the collectivist values of ethnocentrism and xenophobia are defenses against novel infectious diseases harbored in out-groups and to which local people are not adapted. From this, we proposed that high parasite stresses and associated collectivist values, then, promote all the major types of within-region civil conflict. As predicted, based on this, the frequency of civil wars, non-state wars, and coups and revolutions are associated positively with parasite stress and collectivism across countries of the world; peacefulness shows the predicted negative relationships with parasite stress and collectivism. These findings indicate that occurrences of civil conflicts would be reduced by reducing parasite stress and associated collectivist values. The parasite-stress theory of values provides a general causal model of intergroup conflict. The American Civil War is revisited in light of this general model. We provide evidence, too, that the parasite-stress theory of values applies to coalitional conflict characteristic of team sports.
The parasite-stress theory of sociality includes a theory of biodiversity: the parasite-driven-wedge model. Regionally localized coevolutionary races between parasites and their hosts result in three anti-parasite behaviors: preference for in-group affiliation and interaction, out-group avoidance (xenophobia), and philopatry. These three behaviors of behavioral immunity become linked within individuals through genetic linkage disequilibrium. In the case of human cultural behavioral immunity, within-individual linkage of behavioral immunity traits results in what we refer to as cultural linkage disequilibrium. Linkage by either process also includes linkage with genetic immunity to local parasites. These linked traits are mutually reinforcing in that as any one increases in frequency due to its adaptiveness, the others do as well. Also, preference for in-group members with behavioral-immunity values and behavior is self-reinforcing, because the in-group members preferred and favored have the same preference. These events create a wedge that gives rise to intergroup boundaries that effectively fractionate, locally isolate, and diversify the original range of a culture or a species, leading to the genesis of two or more discrete groups from one. The higher the parasite stress in a region, the greater the frequency and intensity of these processes of biodiversity genesis. The parasite-driven-wedge model, then, provides a parapatric (side-by-side) diversification mechanism that we propose accounts for the high diversity of species and cultures in geographical regions of high parasite adversity. Parasite-driven divergence may lead to sympatric speciation, especially at low latitudes, and account for distinct sympatric classes of caste social systems.
The overall goal of our book is to create a synthesis or unity, based on the parasite-stress theory of values/sociality, of many topics that traditionally have been viewed and studied as distinct. The book presents the utility of the parasite-stress theory for unification of areas of research and knowledge ranging from parasitology, immunology, moral systems, civil conflict, governmental systems, family life, sexual behavior, dispersal patterns, personality, economics, violence, religious commitment, biodiversity, and so on. The book supports the claim of the scientific revolution that the realm of explanation is small—diverse and seemingly unconnected parts of nature can be unified by a few shared and basic causes. We hypothesize that emancipation of people from infectious diseases not only will reduce mortality and morbidity and increase liberalism and associated egalitarianism, but also will increase the frequency of scientifically encompassing ideas. We address the societal benefits and costs of emancipating people from infectious diseases. Costs are increased autoimmune disease associated with evolutionarily novel low levels of infectious, commensal and mutualistic organisms encountered by children during their development and the exhaustion of nonrenewable energy for the future coinciding with technological and economic productivity. We respond to a range of criticisms of the parasite-stress theory of values or its claimed empirical support. We conclude that the criticisms to date do not falsify the theory, moderate its application to any of the topics it purports to explain, or question the empirical support of the theory. Numerous future research directions and associated hypotheses are presented.
... Ecological and evolutionary literatures relate disease to the acquisition of culture and socially-learned values and behaviors, including social exclusion and stigma (Curtis et al. 2011;Kurzban and Leary 2001;Oaten et al. 2011). The parasite-stress theory of values and sociality (Thornhill and Fincher 2014), argues for a behavioral immune system that functionally selects values and preferences based on pathogen exposure and shared immunity. High pathogen environments, for example, favor collectivism (i.e., nepotism, xenophobia, and ethnocentrism) while low pathogen environments favor individualism (i.e., liberalism, outgroup tolerance and generosity). ...
... Also, some disease signs are very difficult to conceal because infection induces expulsive defenses (i.e., spitting, vomiting, diarrhea, coughing, sneezing, and rhinorrhea). Finally, evolutionary pressures have enhanced disease detection mechanisms from the long coevolution between humans and parasites (Kurzban and Leary 2001;Thornhill and Fincher 2014). ...
... Evolutionary psychologists argue that cues that suggest the presence of disease-causing pathogens, such as an unhealthy-looking appearance, can trigger protective responses like disgust(Curtis et al. 2011;Kurzban and Leary 2001;Oaten et al. 2011;Thornhill and Fincher 2014). Disgust, in particular, appears to be an evolved response to help individuals avoid contaminated food, objects, and bodily fluids that may carry disease-causing pathogens. ...
I study the social regulation of disease in a search-theoretic economy where health is uncertain and imperfectly observed, and exchange carries the risk of contagion. Traders confront a signal-extraction problem and the equilibrium features a “better safe than sorry” strategy where disease and fear of contagion trigger false alarms, limit the extent of the market, and foster social exclusion. Society’s tolerance toward a disease depends on its danger and visibility. Using these characteristics, I interpret the regulation of the major epidemics in the West (leprosy, plague, smallpox, and cholera) to illustrate how societal anxieties surrounding epidemics fueled prejudice and exclusion.
... Explaining cultural differences in human behavior has a long tradition in evolutionary biology and cultural as well as in social sciences (e.g., Schaller and Murray, 2008;Thomson et al., 2018;Thornhill and Fincher, 2014;Tybur et al., 2016). An evolutionary view suggests that cultures originated from the influence of diseases and are still under pressure of Darwinian selection (Murray and Schaller, 2010;Thornhill and Fincher, 2014), considering both, zoonotic and non-zoonotic diseases. ...
... Explaining cultural differences in human behavior has a long tradition in evolutionary biology and cultural as well as in social sciences (e.g., Schaller and Murray, 2008;Thomson et al., 2018;Thornhill and Fincher, 2014;Tybur et al., 2016). An evolutionary view suggests that cultures originated from the influence of diseases and are still under pressure of Darwinian selection (Murray and Schaller, 2010;Thornhill and Fincher, 2014), considering both, zoonotic and non-zoonotic diseases. Zoonotic diseases are infectious diseases transmitted by non-human animals (Thornhill and Fincher, 2014), while non-zoonotic diseases are transmitted between humans. ...
... An evolutionary view suggests that cultures originated from the influence of diseases and are still under pressure of Darwinian selection (Murray and Schaller, 2010;Thornhill and Fincher, 2014), considering both, zoonotic and non-zoonotic diseases. Zoonotic diseases are infectious diseases transmitted by non-human animals (Thornhill and Fincher, 2014), while non-zoonotic diseases are transmitted between humans. According to it, the parasite stress theory of values and sociality can predict the influence of historical diseases on human cultures (Thornhill and Fincher, 2014). ...
The COVID-19 pandemic severely influenced human behavior due to governmental restrictions. In addition to administrative restrictions, other factors, like historical disease prevalence and culture might impact on recent behavior. The parasite stress theory of values and sociality predicts an influence of historical diseases on human culture and may be of important influence on current human behavioral responses towards the pandemic. To address the influence on behavior, we studied mask use in outdoor recreationists (N = 4863) from 53 cultures. Studying outdoor recreationists is advantageous because people have at least some choices over their mask use, and it is less strictly controlled. We hypothesize that pathogen prevalence and cultural values of a society predict mask usage above and beyond the simplistic explanation of the strength of the governmental pandemic-related restrictions. Our results indicate that societal variables, especially individualism, contribute to the mask use during leisure activities, with people from more individualistic societies reporting lesser mask usage. Further, historic pathogen prevalence has a significant influence on mask use, even when controlling for the stringency measures of the government, HDI and population density. Zoonotic disease richness, however, did not receive significance. A mediation model showed that historical pathogen prevalence had an indirect effect on mask use, via the two pathways collectivism-individualism and governmental regulations. The total effect size of pathogen prevalence on mask use was 0.61, and with 0.24 as direct, and 0.37 indirect effects. Our data fit into the parasite stress theory of values and sociality. Our results 2 provide evidence that the governmental decisions and restrictions themselves are influenced by the historical pathogens.
... The Parasite-Stress Theory (PST) Fincher, 2014b, 2015) suggests how somaticity can have evolutionarily affected a balance between threat and opportunity. The PST refers to pathogenic agents that cause infectious diseases as "parasites' and focuses on non-zoonotic illnesses, i.e., those a human can receive from another human (directly or through a vector) -as opposed to zoonotic illnesses, i.e., those a human can receive from a non-human animal (Thornhill et al., 2010;Fincher and Thornhill, 2012;Thornhill and Fincher, 2014a). The theory proposes that avoiding such diseases has been a primary drive in the evolution of uniquely-human social and psychological characteristics. ...
... Here, we report some of the numerous studies supporting the PST and involving variables particularly relevant to our hypotheses. Consistently with the theory, the analysis of geo-historical data found that the macro-social polarities collectivism-individualism and conservativism-liberalism are strongly correlated to the rate of infectious diseases (Fincher and Thornhill, 2012;Thornhill and Fincher, 2014a;Bennett and Nikolaev, 2020). More collectivist and conservative (/individualistic and liberal) societies are tightly linked to a higher (/lower) presence of infectious diseases. ...
... supporting the idea that innovation is driven by liberalism and nonconformity. Finally, the analysis of data from numerous contemporary-world countries also allowed linking parasitic stress to family ties (Fincher and Thornhill, 2012;Thornhill and Fincher, 2014a). Again, predictably, stronger familial cohesion corresponded to higher infection rates. ...
Attachment is the evolutionarily-established process through which humans create bonds with others to receive care from them. The phenomenon is as essential to our physical survival as it is to our psychological development. An increasing number of studies demonstrates that in sensitive periods during the early years of life, our brain circuitry is programmed in the interactions with our caregivers, with the imprinting of information over multiple attachment dimensions. Adopting a basic brain-computer analogy, we can think of this knowledge as the psycho-social firmware of our mind. According to a recently proposed extension of the classical three-dimensional view, one attachment dimension – somaticity – concerns the caregiver’s task of reflecting and confirming the child’s (internal) states – such as sensations, emotions, and representations – to support the child’s ability to identify and define those entities autonomously. Relying on multidisciplinary evidence – from neuroscientific, developmental, evolutionary, and clinical sources – we suggest that somaticity (H1) has the adaptive function to modulate our tendency to comply and affiliate with a reference group but also (H2) increases the vulnerability to developing Social Anxiety (SA) and Eating Disorders (EDs). We evaluate H1-H2, (1) indicating the evolutionary role of somaticity in modulating our affiliation tendency to optimize the ancestral threat-opportunity balance coming from infectious diseases and (2) showing the deep connection between SA-EDs and the features most closely related to somaticity – interoception and parenting style. Finally, we discuss three relevant implications of H1-H2: (A) Bringing into research focus the adaptive role of our firmware knowledge system versus the hardware (neural substrate) and software (higher cognition) ones. (B) Complementing the well-grounded Objectification and Allocentric Lock Theories, allowing us to integrate multiple levels of explanation on the etiology of psychopathology. (C) Suggesting the design of new psychological treatments. While not aiming to prove H1-H2, our analysis supports them and encourages their direct testing.
... Imitation (a form of cultural transmission) by more ancestrally distant populations may have followed on from this in proportion to the perceived success of this form of sociopolitical organization. Also relevant is variation with respect to factors such as historical pathogen prevalence, which may, via the context-dependent evocation of different ancestral adaptations associated with so-called behavioral immunity (a syndrome of cultural expressions related to degree of in-group preference and out-group hostility that is thought to help control pathogen spread), influence the degree to which the populations of countries are receptive to certain ideologies at different points in their historical development (Thornhill & Fincher, 2014). ...
... It was also found that consanguinity acted as a mediator of the impact of pathogen stress on democracy level, which accords with the prediction that consanguineous mating is an evoked adaptation to such stress as it allows for the conservation within populations of gene complexes that confer resistance to specific diseases (Hoben et al., 2010). Consistent with this hypothesis, consanguineous mating has been found to be part of a broader behavioral immunity syndrome, and co-expresses with heightened negative ethnocentrism (xenophobia), religiosity, and linguistic particularism, which not only function to reduce contact with those harboring novel pathogens (to which the focal group may lack adaptations) but also restricts the inward flow of genes that could potentially disrupt the focal group's locally adapted immunological gene complexes (Thornhill & Fincher, 2014). ...
... The observation that historical disease burdens and GDP per capita are strongly positively predictive of CULV even after the effects of shared ancestry have been controlled indicates that there are other important factors biasing the cultural transmission of Communism. Potentially key among these are more ancient facultative adaptations that evoke cultural insularity in the face of higher historical disease prevalence (Thornhill & Fincher, 2014). Populations among whom the components of behavioural immunity are likely strongly upregulated took longer to become Communist. ...
Domino Theory posits that Communism spreads via emulation or force between nations as a function of geographic adjacency, the theory being so named because this dynamic is often likened to the toppling of dominoes. Using the 1917 Russian Revolution (RR) as a starting point, it is found that geographic distance between Moscow and the capital cities of countries that at one point were or are (either in part or in whole) Communist states strongly predicts the lag (in years) between the RR and the year in which these countries first experienced Communism in some form (r = 0.778, 95% CI = 0.628 to 0.872, n = 45 countries). In a subsample of 36 countries, the pair-wise genetic distance between the population of Russia and the populations of the other countries strongly mediates this relationship. A cladogram based on genetic distance between these national populations indicates strong lambda and kappa signals, meaning that Communism-uptake lag is inversely proportional to the degree of shared ancestry between populations, and that it spreads rapidly among populations once introduced into new regions. Controlling for lambda in regression revealed significant positive influences of historical disease prevalence and GDP per capita on the lag variable. These results suggest that the process that Domino Theory specifies may principally be a function of cultural transmission biased by genetic distance (relative to the population of Russia). Controlling for genetic distance, countries with higher relative wealth and historical disease prevalence experienced Communism later, possibly due to the buffering effects of historical reductions in poverty and of forms of evoked culture that are incompatible with (basic) communist ideology (e.g. strong xenophobia and religiosity, and other cultural expressions of the behavioral immune system). These two terms also interact positively, meaning that among countries exhibiting high historical disease burdens, increased relative wealth inhibited the development of Communism to the greatest degree.
... Following Gorodnichenko and Roland (2017), our IV is the historical prevalence of nine disease-causing pathogens in each country from Murray and Schaller (2010). Thornhill and Fincher (2014) and others developed the parasite-stress theory of values (PSTV) that explains how pathogen prevalence caused the variation in the collectivism-individualism dimension observed today. In a nutshell, the PSTV states that the higher the pathogen prevalence was (and is), the more our ancestors sought to protect themselves from contagion through a strict distinction between outsiders and members of their group. ...
... Consequentially, pathogen prevalence made people more averse toward strangers and develop a collectivist spirit. Vice versa, individualistic societies in regions that have a lower pathogen prevalence place a higher value on autonomy, openness toward new social contacts, and formal regulation as opposed to tradition and norms (Thornhill and Fincher 2014). Because cultural traits are implicitly learned from early childhood and these values are inherited over generations, the pathogen prevalence continues to be a reasonable predictor for individualism today. ...
... It encourages avoidance and rejection of others (Park et al., 2003;Faulkner et al., 2004;Navarrete and Fessler, 2006;Park et al., 2006;Terrizzi et al., 2010), especially those who exhibit cues of infectious disease (Van Leeuwen and Petersen, 2018). Second, disgust and disease-avoidance (i.e., parasite stress) give rise to cultural variants (e.g., socially conservative values and assortative sociality; see Fincher and Thornhill, 2012;Terrizzi et al., 2013;Thornhill and Fincher, 2014), which mitigate social interaction. Third, disgust can promote selfisolation. ...
... Culture plays an important role in the defense against infectious disease. Parasite stress theory suggests that historic exposure to infectious disease affects the evolution of cultural value systems (see Thornhill and Fincher, 2014). In areas of the world in which there are higher rates of infectious disease and more life lost due to infectious disease, there should be more orderliness and strict adherence to social norms. ...
The need to belong is a fundamental aspect of human nature. Over the past two decades, researchers have uncovered many harmful effects of social rejection. However, less work has examined the emotional antecedents to rejection. The purpose of the present article was to explore how disgust––an emotion linked to avoidance and social withdrawal––serves as an important antecedent to social rejection. We argue that disgust affects social rejection through three routes. First, disgust encourages stigmatization, especially of those who exhibit cues of infectious disease. Second, disgust and disease-avoidance give rise to cultural variants (e.g., socially conservative values and assortative sociality), which mitigate social interaction. Third, when the self is perceived as a source of contamination, it promotes shame, which, subsequently, encourages withdrawal from social interaction. Directions for future research are also discussed.
... For example, examining validity data from a series of large-scale individual differences studies, Fischer (2017) re-analyzed data from a number of large scale studies (McCrae et al., 2005;Schmitt et al., 2007;Thalmayer & Saucier, 2014) and found that factor structures and reliabilities tended to improve in more economically developed nations. Drawing upon sociological and institutional research derived from postmodernization theory in sociology (Inglehart, 2018;van de Vijver & Poortinga, 2002;Welzel, 2014), these patterns were interpreted in evolutionary terms as resource vs threat trade-offs (Inglehart, 2018;Thornhill & Fincher, 2014): individuals are more likely to fully express their behavioral preferences, if they have sufficient resources and are less likely to face existential threats that constrain behavioral expressions. ...
... These different lines of evidence suggest that survey responses may have been affected by population-level increases in stress and anxiety during the pandemic. These effects constitute a possible proximal effect of acute stress on survey responses and factor structures during a specific event (see Sutin et al., 2020), whereas resource vs threat models often model long-term threats that involve extended exposure and therefore adaptive responses which are associated with changes in personality structure over time (Fischer, 2017(Fischer, , 2021aThornhill & Fincher, 2014;Van de Vliert, 2009. The pandemic provides an interesting opportunity to examine the effect of acute stress at the population level on personality structure. ...
We report systematic variability in the psychometric properties of a brief personality inventory during the early stages of the COVID-19 pandemic. Drawing upon recent discussions about the universality vs cultural relativism of personality measures, we review and comparatively test theories predicting systematic variability in personality measurement across cultures using an established brief personality measure applied to population samples in 16 nations during the first wave of the COVID-19 pandemic (N=35,052). We found systematic variation in factor replicability and effective dimensionality. In line with previous theorizing, factors replicated better in contexts with greater niche diversity. Examining possible drivers underlying this association, the investigation of the individual components in the niche construction index suggested that life expectancy and to a lesser degree economic complexity are associated with greater personality structure differentiation. Population-level indicators of acute threat due to COVID-19 did not show credible effects. These patterns suggest that a) investigation of personality structure in population samples can provide useful insights into personality dynamics, b) socioecological factors have a systematic impact on survey responses, but c) we also need better theorizing and research about both personality and culture to understand how niche construction dynamics operate.
... We believe that reverse causality is rather unlikely to run from green bond issuance to culture, previous studies postulate that beliefs, values and preferences are changing slowly (Guiso et al., 2006). To address the endogeneity challenge, we apply a two-stage least square (2SLS) and a generalized method of moments (GMM) estimation model using a country-based measure of prevalent infectious diseases as an external instrument for national culture (Boubakri et al., 2021;Thornhill & Fincher, 2014). Our findings remain qualitatively unchanged. ...
... Prevalent infectious diseases bring morbidity and thereby influence the course of natural selection (Wolfe et al., 2007) Countries with strong historical prevalence of infectious diseases are more likely to develop specific social attitudes towards their prevention, such as prejudice, isolation and ethnocentrism. Drawing on these findings, business studies analyzing the effect of cultural value dimensions on economic outcomes have used the index of historical prevalence of infectious diseases as an external instrument for cultural values (Boubakri et al., 2021;Thornhill & Fincher, 2014). Table 8 presents the results for the 2SLS estimator. ...
We analyze the impact of Hofstede's culture dimensions
on green bond issuance in 84 countries during 1991–2021,
using novel International Monetary Fund data. We control
for environmental, macroeconomic and institutional
factors. Our results show that countries that score higher
on individualism, masculinity and indulgence are associated with lower green bond issuance, whilst countries that
score high on long‐term orientation and uncertainty
avoidance are associated with higher green bond issuance.
Culture appears to play a role in green bond market
development. The culture effect remains broadly robust
after applying sensitivity and endogeneity tests, adding
new controls and performing coefficient stability and
dominance analysis.
... For example, examining validity data from a series of large-scale individual differences studies, Fischer (2017) re-analyzed data from a number of large scale studies ( McCrae et al., 2005 ;Schmitt et al., 2007 ;Thalmayer and Saucier, 2014 ) and found that factor structures and reliabilities tended to improve in more economically developed nations. Drawing upon sociological and institutional research derived from postmodernization theory in sociology ( Inglehart, 2018 ;van de Vijver and Poortinga, 2002 ;Welzel, 2014 ), these patterns were interpreted in evolutionary terms as resource vs threat trade-offs ( Inglehart, 2018 ;Thornhill and Fincher, 2014 ): individuals are more likely to fully express their behavioral preferences, if they have sufficient resources and are less likely to face existential threats that constrain behavioral expressions. ...
... These different lines of evidence suggest that survey responses may have been affected by population-level increases in stress and anxiety during the pandemic. These effects constitute a possible proximal effect of acute stress on survey responses and factor structures during a specific event (see Sutin et al., 2020 ), whereas resource vs threat models often model long-term threats that involve extended exposure and therefore adaptive responses which are associated with changes in personality structure over time ( Fischer, 2017( Fischer, , 2021aThornhill and Fincher, 2014 ;Van de Vliert, 2009, 2013. The pandemic provides an interesting opportunity to examine the effect of acute stress at the population level on personality structure. ...
We report systematic variability in the psychometric properties of a brief personality inventory during the early stages of the COVID-19 pandemic. Drawing upon recent discussions about the universality vs cultural relativism of personality measures, we review and comparatively test theories predicting systematic variability in personality measurement across cultures using an established brief personality measure applied to population samples in 16 nations during the first wave of the COVID-19 pandemic (N = 35,052). We found systematic variation in factor replicability and effective dimensionality. In line with previous theorizing, factors replicated better in contexts with greater niche diversity. Examining possible drivers underlying this association, the investigation of the individual components in the niche construction index suggested that life expectancy and to a lesser degree economic complexity are associated with greater personality structure differentiation. Population-level indicators of acute threat due to COVID-19 did not show credible effects. These patterns suggest that a) investigation of personality structure in population samples can provide useful insights into personality dynamics, b) socioecological factors have a systematic impact on survey responses, but c) we also need better theorizing and research about both personality and culture to understand how niche construction dynamics operate.
... This in turn could lead to prejudicial attitudes and avoidance behaviors towards individuals with physical disabilities and disfiguring conditions. This proposition of the behavioral immune system (Murray & Schaller, 2016) holds that humans evolved psychological mechanisms to avoid interactions and contacts with those who are perceived as carrying communicable pathogens and diseases (Kurzban & Leary, 2001;Thornhill & Fincher, 2014). According to Park et al. (2003) the psychological disease avoidance adaptations that evolved for pathogens might also respond to noncontagious disease cues such as physical disabilities. ...
Derived from the disease-avoidance model is the hypothesis that people may direct negative cognitive and behavioral responses towards individuals with physical disfiguring conditions, including physical disabilities. Based on this proposal of a behavioural immune system, physical disability, a noncontagious physical disfiguration, may falsely activate cognitive disease-avoidance processes resulting in prejudicial or negative responses against individuals with physical disabilities. For the first time this hypothesis is put to the test by investigating whether ratings of attractiveness and comfort for a social interaction vary systematically with physical disability (Studies 1 and 2). In addition, we tested whether these ratings were associated with individual differences in pathogen disgust, perceived vulnerability to disease, and concern for contracting COVID-19. In Study 3 we overcame possible methodological limitations by employing a virtual reality environment and using both male and female models. A fourth study was conducted to extend the first two studies by using a more diverse set of avatars. Results from Studies 1 and 2 indicated that disability did not significantly impact comfort ratings for social interactions, although nondisabled stimuli were rated as more attractive. However, Study 3 showed that in a VR environment, participants preferred closer proximity to nondisabled avatars, regardless of gender, over disabled ones, a preference not mitigated by the presence of prosthetics. Study 4 replicated these findings with varied 2D avatars, showing that disability significantly affected both comfort and attractiveness ratings, with nondisabled avatars rated highest, followed by those with prosthetics, and finally disabled avatars. Despite these findings, the expected relationship between comfort ratings and individual differences in pathogen disgust or perceived infectability did not emerge, challenging the behavioral immune system hypothesis. The discomfort associated with physical disability may be more related to social stigma or 3 preconceived notions than to an innate disease-avoidance response. In conclusion, this research contributes to understanding how physical disability influences social comfort and attractiveness perceptions, challenging the behavioral immune system hypothesis and highlighting the role of social and cognitive factors in these judgments.
... Concerning religiosity, Fincher and Thornhill (2012) found that regional differences in historic parasite stress were positively correlated with religious participation and value, even after controlling for critical confounding variables (e.g., economic development). Along similar lines, Thornhill and Fincher (2014b) demonstrated that geographical differences in infectious disease richness were positively correlated with the diversity of religions. Put another way, in regions of the world that are characterized by a high prevalence of pathogenic microorganisms, there exists a greater number of religious affiliations. ...
... COVID-19 ravaged Chile after emerging in China; the Spanish Flu ravaged India after emerging in the US; and the Black Death ravaged England after emerging in the Asian Steppe. The parasite stress literature proposes that these types of events have also occurred at smaller scales over the course of human evolution, with foraging groups on one side of a river or valley importing novel pathogens to neighbouring groups (Thornhill & Fincher, 2014). A key proposition within this literature suggests that xenophobia has evolved in humans partially to reduce the infection threats posed by intergroup contact. ...
Multiple proposals suggest that xenophobia increases when infectious disease threats are salient. The current longitudinal study tested this hypothesis by examining whether and how anti-immigrant sentiments varied in the Netherlands across four time points during the COVID-19 pandemic (May 2020, February 2021, October 2021 and June 2022 through Flycatcher.eu). The results revealed that (1) anti-immigrant sentiments were no higher in early assessments, when COVID-19 hospitalizations and deaths were high, than in later assessments, when COVID-19 hospitalizations were low, and (2) within-person changes in explicit disease concerns and disgust sensitivity did not relate to anti-immigrant sentiments, although stable individual differences in disgust sensitivity did. These findings suggest that anecdotal accounts of increased xenophobia during the pandemic did not generalize to the population sampled from here. They also suggest that not all increases in ecological pathogen threats and disease salience increase xenophobia.
... Además, las personas responden no solo a motivaciones personales e interpersonales, sino también a valores y normas culturales, los cuales no se pueden ver como algo estático o pétreo, pues la evidencia deja claro que a medida que las normas evolucionan con el tiempo, con ellas también lo hace nuestra psicología (Henrich y Muthukrishna 2020). De esta manera, se ha encontrado que los valores y el comportamiento de las personas están moldeados en gran medida por el grado en que la supervivencia es segura, la cual fue muy frágil durante la mayor parte de la historia, alentando un gran énfasis en la solidaridad grupal, el rechazo de los forasteros y la obediencia a líderes fuertes (Thornhill y Fincher, 2014). Así, bajo una escasez extrema, la xenofobia se vuelve más saliente. ...
Este artículo analiza el fenómeno de la desigualdad en la distribución de la riqueza desde una perspectiva psicosocial, enfatizando en la dimensión cultural individualista-colectivista. En una primera parte teórica comienza describiendo algunos aportes de la perspectiva de la psicología social sobre la desigualdad en la distribución de recursos económicos. En una segunda parte revisa varios estudios científicos recientes sobre la relación entre el individualismo-colectivismo cultural y la desigualdad económica. Finalmente, plantea las conclusiones y limitaciones del trabajo, y propone futuras líneas de investigación.
... Exposure to pathogens may be another factor. It has been posited that exposure to diseases may have the effect of binding individuals in a society more closely to one another (Thornhill and Fincher 2014;Zaleskiewicz et al. 2015). This seems to have been the case during the COVID-19 pandemic, as individuals more exposed to the pandemic seem to have increased their propensity to help others (Grimalda et al. 2021), albeit perhaps only temporarily (Gambetta and Morisi 2022). ...
Trust is key for economic and social development. But why do we trust others? We study the motives behind trust in strangers using an experimental trust game played by 7236 participants, in six samples representative of the general populations of Germany, Italy, Japan, Luxembourg, the UK and the USA. We examine the broadest range of potential determinants of trustor sending to date, including risk tolerance, preferences for redistribution, and conformity. We find that even though self‐interest, indicated by expected returns, is relevant for trustor behaviour, the most important correlate of sending is participants' altruism or fairness concerns, as measured by giving in a dictator game. We also find that in our large and representative sample, behaviour in the trust game and responses in a trust survey are significantly correlated, and that similar correlates—altruism in particular—are relevant for both.
... Environmental features such as pathogen prevalence and resource scarcity may influence women's partner choice. According to Thornhill and Fincher (2014), there is support for parasite stress affecting human sexual selection and mating systems; parasite stress is positively associated with women's sexual restrictiveness across nations. Female scarcity has also been suggested to be more important than wealth and parasite load in shifting people between shortterm sexual behavior and long-term committed relationship. ...
... Interestingly, the Parasite Stress Theory of Values [3][4][5] implies that the historical occurrence of infectious diseases may have played a role in the development of Individualist and Collectivist cultural differences [1b]. Societies with a high caliber of pathogenic stress were more liable to develop a collectivist culture that accommodates a gregarious aegis against infectious disease spread, whereas societies with a low caliber of pathogenic stress developed individualistic value systems [3]. ...
This study explores the fascinating connection between culture and societal responses to pandemics. A significant issue for public health is influencing how the broader public reacts to pandemics. The preventive actions (such as donning masks and minimizing group gatherings) that aid in mitigating the spread of pandemics have been shown to be inadequately implemented in various places during the most recent pandemic influenza, the 2009-10 H1N1 pandemic, and the ongoing COVID-19 outbreak. Regional differences in public preventive intervention were observed; owing to cultural values variables. Across the continents 209 COVID-19 pandemic-affected countries reportedly adopted standard preventive protocols for COVID-19, but the pandemic spread and onslaught showed different patterns in different countries. Humans have a natural tendency to maintain or not maintain physical distance from one another. This tendency stems from a nation's culture, which is ingrained in its national heritage and traditions. The current pandemic scenario offers a governmental and societal level opportunity to study how flexible and adaptable cultures are between pandemic responses. In this study, culture was defined using Hofstede's dimensions Individualism/Collectivism. An exploratory case-study methodology was taken after employing a post-positivist approach. The study findings indicated collectivism encourages faster and more effective COVID-19 responses and hence suggests cultural adjustments for the purpose of infectious disease preventive intervention.
... Es decir, que las influencias situacionales darían paso a un patrón cultural más consistente en la medida en que se vuelven crónicas. De esta manera, por ejemplo, cuando las condiciones de seguridad existencial permiten una mayor autonomía individual entonces el individualismo se haría más saliente, mientras que cuando tales condiciones de vida son más restrictivas, amenazantes e inseguras, dificultan la autonomía, volviendo más salientes al colectivismo y la centralidad del grupo, del cual se percibe mayor dependencia (Inglehart, 2018;Páez et al., 2003;Thornhill y Fincher, 2014;. ...
En la visión de las orientaciones culturales individualista y colectivista como cognición situada, se asume que estas se pueden inducir y modificar hasta cierto punto, pero persisten interrogantes acerca de los mecanismos por los que esto ocurre. Este estudio cuasiexperimental examina el efecto de los siguientes tipos de priming: agentivo individualista, agentivo colectivista, narrativo individualista y narrativo colectivista, comparados con un priming neutral, en una muestra de adolescentes costarricenses en primer año de educación secundaria (N = 173; 57% mujeres; Medad =12.87, DEedad = 0.75 años). Los resultados constataron efectos distintos de acuerdo con el tipo de priming, siendo que el agentivo indujo más actitudes individualistas que el narrativo. El agentivo colectivista activó en menor medida el autoconcepto independiente, caracterizado por el interés propio, en comparación con los otros tipos de priming. Las implicaciones teóricas y metodológicas de estos hallazgos son discutidas.
... The disease environment has been identified as a causal factor determining the relative strength of individuals versus groups. Specifically, Fincher et al. (2008) have put forward a pathogen theory of group bias, arguing that in areas with historically higher infectious disease burdens, societies developed stronger ingroup biases as a defensive strategy (see Thornhill & Fincher, 2014, for a review of work in this area). Because interactions with strangers are perceived to increase the risk of infection, people biased their dealings inwards in the context of identified ingroups. ...
We review work that has linked economic inequality and culture to governance quality. We start with contributions that have considered the relationship between inequality and governance from a long-run perspective. This historical perspective yields a range of insights and helps identify the deep drivers of specific cultural traits that relate to both economic inequality and gover-nance in contemporary societies. We then survey work that has linked inequality and culture to governance in present-day settings. We identify the complexity of the relationships with causality between any pair of these variables running both ways. These causal patterns, in turn, imply that countries may end up in either a good equilibrium characterized by lower economic inequality , the "right" culture and good governance, or a bad equilibrium described by greater inequality, the "wrong" culture and bad governance. We conclude with a range of policy implications.
... Uno de estos casos es el historial de enfermedades contagiosas (Fincher et al., 2008), que provocarían que los grupos se vuelvan más cerrados y rígidos (Gelfand et al., 2011), y valoren más la obediencia y el conformismo frente a las normas sociales, debido a su búsqueda de protección frente a la amenaza sanitaria. Según la teoría del estrés por parásitos ("parasite stress theory"), cuando los grupos humanos se ven crónicamente amenazados por Individualismo y colectivismo enfermedades contagiosas, esto los lleva a volverse más colectivistas, más etnocéntricos y más xenofóbicos, como una respuesta defensiva frente al peligro de enfermar gravemente (Thornhill & Fincher, 2014). ...
La importancia de la cultura en la desigualdad es reconocida en la literatura académica, pero no es claro a través de qué mecanismos se relacionan ambos fenómenos. El presente estudio examinó la influencia de la orientación cultural individualista-colectivista ante la desigualdad en la distribución de recursos en adolescentes costarricenses (N = 264, M edad = 13.42 años, DE edad = .72, 50.8 % mujeres). Se realizó un estudio cuasiexperimental con un priming agentivo en tres condiciones (individualista, colectivista y control) como variable independiente, y el Juego del Ultimátum -JdU- (en versión de pago por trabajo) como variable dependiente. Como covariables se incluyeron el autoconcepto independiente e interdependiente, la percepción de la desigualdad en la vida cotidiana, la preocupación por el dinero, la religiosidad, la autopercepción de clase social y las características sociodemográficas. Se encontró una asociación significativa entre el priming individualista y un mayor rechazo a los tratos altamente desiguales, aunque no así con los tratos moderadamente desiguales, y no hubo significación con el priming colectivista. Estos hallazgos indican que las orientaciones culturales juegan un papel relevante en el comportamiento ante la desigualdad social. Este estudio representa una innovación metodológica al relacionar técnicas de priming con técnicas de juegos económicos.
... 13 In a study in which he is interested in identifying the effects of culture on institutions, Maseland (2013) uses the pathogen Toxoplasma gondii as an instrument for a number of cultural traits. This pathogen is uncommon as a cause of manifest disease but has been shown to cause a number of personality 13 In Thornhill and Fincher (2014), this is referred to as the 'parasite stress theory of cultural values'. Morand and Walther (2018) examine the flipside of this theory and hypothesize that more individualistic societies suffer from a higher number of infectious disease outbreaks. ...
It is now abundantly clear that social norms channel behaviour and impact economic development. This insight leads to the question: How do social norms evolve? This survey examines research that relies on geography to explain the development of social norms. It turns out that many social norms are either directly or indirectly determined by geography broadly conceived and can, hence, be considered largely time invariant. Given that successful economic development presupposes the congruence between formal institutions and social norms, this insight is highly relevant for all policy interventions designed to foster economic development. In a companion paper, the role of religion and family organization as potential mediators between geography and social norms assumes centre stage.
... Exposure to pathogens may be another factor. It has been posited that exposure to diseases may have the effect of binding individuals in a society more closely to one another (Thornhill and Fincher 2014;Zaleskiewicz et al. 2015). This seems to have been the case during the COVID-19 pandemic, as individuals more exposed to the pandemic seem to have increased their propensity to help others (Grimalda et al. 2021), albeit perhaps only temporarily (Gambetta and Morisi 2022). ...
... While infectious disease may also be regarded as a security threat (Stevens & Vaughan-Williams, 2016)-indeed, there is "an entire scientific literature on how infectious diseases promote authoritarianism" (Kealey, 2021)-the focus of much of that literature is on its relationships with authoritarian attitudes and practices at the aggregate rather than at the individual level, with countries that have a high incidence of infectious disease being more authoritarian. Parasite-or pathogen-stress theory (Thornhill & Fincher, 2014) finds a link between authoritarian governance and infectious disease over space and time (Pericas, 2020) that may be due both to evolutionary psychology and to the need for conformity in cultures to limit its spread (Tybur et al., 2016), and mediated by the behavioral immune system (Helzer & Pizarro, 2011;Murray & Schaller, 2012;Murray et al., 2013). Zmigrod et al. (2021) confirm a relationship between authoritarian attitudes and infectious disease in the 47 countries they examine, but they make an additional connection to voting behavior, with data from the United States showing a path from prevalence of infectious disease through authoritarian attitudes to voting for Donald Trump. ...
This article offers a new perspective on when and why individual-level authoritarian perceptions of security threats change. We reexamine claims that authoritarian members of the public responded to the COVID-19 pandemic in a counterintuitive fashion. The response was counterintuitive in that, rather than a desire for a stronger government with the ability to impose measures to address the pandemic and its consequences, authoritarian individuals rejected a stronger government response and embraced individual autonomy. The article draws on perceptions of security threats—issues that directly or indirectly harm personal or collective safety and welfare—from surveys in two different contexts in England: 2012, when perceptions of the threat from infectious disease was low relative to most other security threats, and 2020, when perceptions of the personal and collective threat of COVID-19 superseded all other security threats. We argue that the authoritarian response was not counterintuitive once we account for the type of threat it represented.
... Second, some work has proposed that the behavioral immune system treats outgroup membership as a pathogen cue 60,[87][88][89][90] . This outgroup avoidance account proposes that inferring infection risk from group membership is a design feature rather than a bug or by-product, because outgroup members have putatively posed greater pathogen threats during human evolution than ingroup members. ...
... 13 In a study in which he is interested in identifying the effects of culture on institutions, Maseland (2013) uses the pathogen Toxoplasma gondii as an instrument for a number of cultural traits. This pathogen is uncommon as a cause of manifest disease but has been shown to cause a number of personality 13 In Thornhill and Fincher (2014), this is referred to as the 'parasite stress theory of cultural values'. Morand and Walther (2018) examine the flipside of this theory and hypothesize that more individualistic societies suffer from a higher number of infectious disease outbreaks. ...
... For example, in the aftermath of the 2008 financial crisis (Sortheix et al., 2019) and exposure to war (Daniel et al., 2013), early adolescents' conservation values became more important, while motivationally opposing values, including selfdirection, stimulation, and hedonism, weakened. According to evolutionary theory, the collective behavioral reactions to major infectious diseases could lead to adaptive change in an individual's value orientations (Thornhill and Fincher, 2014). To reduce disease spread during a disaster, behavioral avoidance systems (e.g., decreased out-group contact) and conservation values may be activated (Woltin and Bardi, 2018). ...
Adolescence is a critical period for formulating and developing value orientations. The COVID-19 pandemic has dramatically restricted people’s lives, potentially leading adolescents to reevaluate what they prioritize in life (i.e., their values) and affecting their mental health. Previous studies suggest that Chinese early adolescents’ group orientation is negatively associated with mental health more strongly in rural than in urban, whereas this rural–urban differs may vary after the outbreak of the pandemic. To examine potential changes in group orientation, mental health, and their associations during the pandemic, two cross-sectional surveys of ninth-grade students in the same three school were conducted in rural and urban China in 2019 and 2021. The results showed that compared with students before the pandemic (2019, N = 516, 48.8% girls, Mage = 14.87 years), students during the pandemic (2021, N = 655, 48.1% girls, Mage = 14.80 years) displayed lower group orientation such as group responsibility and rule abiding of rural students, and higher loneliness and depressive symptoms. Social equality, group responsibility and rule abiding were all significantly negatively associated with loneliness and depressive symptoms. Those negative associations were stronger in the urban regions than in the rural region. Follow-up invariance analysis revealed that this rural–urban difference in the relations between social equality, group responsibility, and rule abiding and mental health problems was only significant during (and not before) the pandemic. The protective effect of group orientation on mental health seems to be weakened only in rural contexts. The results suggest that significant changes in macrolevel contexts may play an important role in shaping adolescents’ value orientation and mental health.
While business studies on gender have increased, they continue to adopt traditional approaches with limited samples drawn from general populations (e.g., students and teachers). In contrast, we investigate gender differences with our focus solely on business professionals. Specifically, we study 40 societies using the four dimensions of subordinate influence ethics (SIE) behaviors: pro-organizational behaviors, image-management behaviors, self-serving behaviors, and maliciously intended behaviors. We employed crossvergence theory as our theoretical foundation, with its two competing forces, sociocultural (gender differences) and businessideological (no gender differences), which translates to a global-business-subculture effect. We found no gender differences for three of the four SIE behaviors and minimal differences for the fourth for our sample of business professionals. Thus, our findings differ significantly from those of previous general-population samples. We also tested for societal-level moderating effects of collectivism and individualism using the business values dimensions (BVD) measure. Our individualism findings, the primary values dimension associated with business success, in conjunction with findings from other studies, support our nonsignificant SIE differences findings. In sum, the truly minimal gender differences that we found provide strong support for the perspective that there is a global-business-subculture effect. Our findings also suggest that ethical differences between genders are minimal across the global workforce. We discuss the implications for international business.
Using a computational social science approach integrating evolutionary psychology, social psychology, and intergroup relations, this research examined associations between disease threats and group identification across cultures by analyzing the relationship between COVID-19 threats (actual and perceived) and first-person plural versus singular pronoun usage—a linguistic marker of collective identity. Two studies analyzed epidemiological and Google Trends search data over 154 weeks: Study 1 established baseline patterns using U.S. data, while Study 2 investigated cross-cultural variations globally. Through transfer function methodology to pre-whiten time series data for cross-correlation function analysis and random-slope-random-intercept multilevel modeling, the research explored temporal dynamics of threat-identification relationships. Results indicated that perceived COVID-19 threat, measured through pandemic-related search volumes, exhibited consistent correlations with increased first-person plural pronoun usage across both studies. While COVID-19 cases demonstrated non-significant relationships globally but positive associations in the U.S., mortality rates showed negative correlations with first-person plural pronoun usage globally, differing from U.S. patterns. Cultural collectivism emerged as a moderating factor in the global analysis, with individualistic cultures displaying stronger associations between perceived threat and collective linguistic markers. These findings contribute to our understanding of the relationship between collective threats and group identification processes across cultures while demonstrating the potential of computational linguistic analysis for monitoring real-time collective responses to pandemics, offering insights relevant to preparedness strategies for future global challenges.
The impact of the COVID‐19 pandemic on xenophobia in South Africa is little understood. The Behavioural Immune System (BIS) theory would predict that hostility towards immigrants increases during periods of heightened pathogen stress. This BIS‐hypothesis is tested against the relative strength of three other possible drivers of anti‐immigrant sentiment. These included anger at the national lockdown system, intertemporal relative deprivation, and racial transformation ideology. For these tests nationally representative data ( N = 2996), gathered during the height of the ‘Omicron’ wave, were used. Multivariate analysis showed that COVID‐19 exposure was not associated with more negative sentiments towards immigrants. Fear‐based reactions to the Coronavirus were, in fact, correlated with pro‐immigrant attitudes. Intertemporal relative deprivation and transformation orientations were much better predictors of anti‐immigrant sentiment than pathogen stress. These findings raised questions about the applicability of the BIS‐hypothesis in the context of the Coronavirus and suggest new avenues of academic inquiry.
This paper examines the impact of ultraviolet radiation (UV‐R) on state capacity. The results indicate that the intensity of UV‐R is a strong predictor of cross‐country differences in state capacity. Countries with a higher degree of UV‐R exposure tend on average to have weaker states. This finding remains unaffected after controlling for different variables that may be correlated with both UV‐R and state capacity, including an extensive set of geographical, historical and contemporary factors. The observed link between sunlight and state capacity is not driven by potential outliers and is robust to the employment of alternative measures of state capacity, estimation methods and other sensitivity checks. Furthermore, the analysis also reveals that the individualistic–collectivist dimension of culture acts as a transmission channel connecting UV‐R and state capacity. The estimates show that a lower degree of UV‐R exposure leads to the adoption of individualistic values, which in turn contribute to the development of state capacity.
Unfamiliar individuals are viewed with suspicion across the entire animal kingdom. This makes evolutionary sense, as outsiders may carry unfamiliar pathogens against which one has not yet developed immune defenses. In humans, the unfamiliar-pathogens idea has been dismissed on the grounds that people do not shun microbe-sharing contact with ethnic outgroups (other “races”) more than they do with ingroups. Reanalyzing the same public data on which such claims are based—6500 participants from China, India, USA, and UK—here I show that (1) people do behave as though the parasites of unfamiliar individuals were more dangerous, and (2) strangers’ ethnicity matters when, and only when, it is a proxy for unfamiliarity. This implies that racism could be tamed by acquainting our children with fellow humans of all shapes and colors, so that everyone in the world looks like family.
QAnon's rallying cry of “the storm” on January 6 and thereafter articulates a structural taxonomy of planetary scale and apocalyptic eschatology that pervades the environmental imaginaries of contemporary fascism. While they become visible only in times of emergency and states of exception, this essay argues that equal attention needs to be paid to expressions and operations of ecofascism in the mundane places and practices of everyday life. Expanding beyond the geographic and historical specificities of Nazism and its transatlantic dialogue with North American settler colonialism, this essay theorizes everyday ecofascism as an oiko-logics and oiko-nomics across borders, a transversal condition of deeply globalized, inextricably interconnected structures and systems.
Evidenz bzw. evidenzbasierte Maßnahmen stellen einen Eckpfeiler gegenwärtiger Politik sowie deren Kommunikation dar. In polarisierten Zeiten scheint es sich so darzustellen, dass wissenschaftlich valide Evidenz einen der wenigen Ankerpunkte darstellt, die zwecks Orientierung zur Verfügung steht. Dieser Beitrag beleuchtet die historische Genese des evidenzbasierten Ansatzes, indem er eingangs dessen Vorgänger darstellt, anschließend exemplarische Gründe anbietet wieso dieser ersetzt werden musste und schließlich die Grundannahmen, unterliegenden Vorstellungen sowie Weltbilder des evidenzbasierten Ansatzes darstellt. Der Beitrag endet mit einer kritischen Reflexion bzgl. des Transferpotenzials von evidenzbasierter Wissenschaft in politische Maßnahmen.
What environmental factors are associated with individual differences in political ideology, and do such associations change over time? We examine whether reductions in pathogen prevalence in U.S. states over the past 60 years are associated with reduced associations between parasite stress and conservatism. We report a positive association between infection levels and conservative ideology in the United States during the 1960s and 1970s. However, this correlation reduces from the 1980s onwards. These results suggest that the ecological influence of infectious diseases may be larger for older people who grew up (or whose parents grew up) during earlier time periods. We test this hypothesis by analyzing the political affiliation of 45,000 Facebook users, and find a positive association between self-reported political affiliation and regional pathogen stress for older (>40 years) but not younger individuals. It is concluded that the influence of environmental pathogen stress on ideology may have reduced over time.
Objetivo: en este artículo de reflexión se propone analizar la relación de la orientación individualistacolectivista de la cultura con la desigualdad socioeconómica desde un enfoque evolutivo. Método: consiste en un análisis conceptual basado en una revisión de literatura científica, tanto clásica como actual, de la cual se hizo una interpretación crítica. El trabajo comienza con una introducción que sitúa la temática en el contexto de la psicología social evolutiva. Luego se plantea la distinción entre evolución biológica y cultural. Resultados: con base en los referentes conceptuales anteriores, se analizan las nociones de individualismo y colectivismo cultural desde una perspectiva de psicología social evolutiva. Posteriormente, se plantea una visión evolutiva de la desigualdad y, por último, se ofrece una panorámica entre el individualismo-colectivismo cultural vinculado a la desigualdad en la distribución de la riqueza, también desde el enfoque de psicología social evolutiva. Conclusiones: se postulan algunas reflexiones generales derivadas de los análisis anteriores. Estas proponen que la orientación cultural individualista-colectivista es un producto evolutivo de las sociedades que puede influir en el modo en que estas se estructuran, organizan y distribuyen su riqueza. Ello puede ser entendido en el contexto de las circunstancias que estas han enfrentado y la forma en que han respondido a las mismas a través de su historia evolutiva. La tendencia a que en las sociedades más colectivistas se presente mayor desigualdad en la distribución de la riqueza podría estar permeada por una mayor propensión al conformismo, la pasividad, la obediencia y el sometimiento a las jerarquías sociales, lo que sugiere que la desigualdad socioeconómica, más que un proceso puramente económico, es también un proceso político-cultural y evolutivo.
Public health interventions targeting coughing and spitting during the Tuberculosis and 1918 flu epidemics were largely successful. Specifically, public health officials' messaging framed the behavior of spitting as repulsive and endangering to others, prompting an elicitation of disgust. Anti-spitting campaigns - messaging that focuses on the threat of spit or sputum - have long been common during pandemics and manifested once again to combat the spread of COVID-19. Yet, few scholars have theorized if and how anti-spitting campaigns function to change behavior. One possibility is parasite stress theory, which posits that human behavior is driven by a desire to avoid pathogenic threats like spit. The application of these types of disgust appeals in public health messaging remains understudied and warrants exploration. To test the applicability of the parasite stress theory, our message experiment with US adults (N = 488) examined reactions to anti-spit messages that varied in visual disgust (low and high). For more highly educated respondents, the high disgust appeal directly decreased spitting intentions, and this relationship was stronger for individuals with higher levels of pathogen and moral disgust. Given the importance of public messaging during pandemics, future research should continue to examine the efficacy and theoretical underpinnings of specific disgust appeals.
En este trabajo se presenta una síntesis y discusión sobre la presencia de patologías congénitas y defectos del desarrollo en individuos de diferentes periodos arqueológicos de la costa de la región de Antofagasta, en el norte de Chile, las que se concentran en el esqueleto axial. A pesar de que la muestra analizada presenta un número bajo (n = 6), se realiza una comparación con casos reportados para la zona costera de Arica y Tarapacá, obteniéndose que la diferencia entre ambas zonas no es estadísticamente significativa. Considerando antecedentes ambientales y etnohistóricos de la zona, se propone que una combinación a la exposición de diferentes contaminantes naturales, junto a un sistema de parentesco endogámico, serían las causas más probables de la aparición de estas patologías.
The Covid-19 pandemic exposed individuals to intense restrictions and social isolation, as well as the possibility of deterioration of physical health. In the pandemic period, the Internet has become the principal avenue for social interaction, leisure related activities, and school-work pursuits for most people and consequently problematic Internet use (PIU) has increased dramatically in this period. Modeling of PIU among university students - considered one of the most negatively affected groups at this time - along with PIU subconstructs as well as indicators of psychological well-being - life satisfaction, loneliness, and hostility - will be valuable in directing future studies. This study examined the effects of the psychological well-being indicators of life satisfaction, loneliness, and hostility on PIU constructs; the preference for online social interaction, Internet use for mood regulation, and deficient self-regulation of Internet use during the Covid-19 pandemic social isolation period. Participants were 418 undergraduate students from a public university (130 male and 288 female). Results revealed that young adults with low life satisfaction have been more likely to problematically use the Internet to regulate their mood during the Covid-19 pandemic. Hostility and loneliness between which there is a moderately strong direct relationship, were similarly related to deficiently self-regulated Internet use. Moreover, individuals experiencing feelings of loneliness are more likely to use the Internet problematically for online social interaction purposes, while those experiencing feelings of hostility are more likely to use it problematically for mood regulation purposes. Given the significant relationships between indicators of psychological well-being and PIU, higher education institutions should take measures to prevent PIU behaviors in their students in case they face potential periods of social isolation.
The USA has been particularly hard hit by the COVID-19 pandemic and a wide spatial variation can be seen in its spread and mortality. This raises the question of why some regions are more resilient to the pandemic than others? We hypothesize that the individualism–collectivism cleavage explains the disparity in COVID-19 cases observed across sub-national units in the USA. Cultural disparity among different groups of people leads to differences in how they perceive health crises and thereby shapes the way they respond to pandemics. A heightened sense of obligation and responsibility increases in-group sociability and interdependence and raises the perceived vulnerability towards disease transmission among collectivistic individuals, and this leads to greater adherence to containment measures and social distancing rules. Our results provide evidence that more individualistic states tend to have more COVID-19 cases across the USA.
Although the individualism–collectivism dimension is usually examined in a U.S. versus Asian context, there is variation within the United States. The authors created an eight-item index ranking states in terms of collectivist versus individualist tendencies. As predicted, collectivist tendencies were strongest in the Deep South, and individualist tendencies were strongest in the Mountain West and Great Plains. In Part 2, convergent validity for the index was obtained by showing that state collectivism scores predicted variation in individual attitudes, as measured by a national survey. In Part 3, the index was used to explore the relationship between individualism–collectivism and a variety of demographic, economic, cultural, and health-related variables. The index may be used to complement traditional measures of collectivism and individualism and may be of use to scholars seeking a construct to account for unique U.S. regional variation. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The authors examine the hypothesis that the intelligence of the population is a major factor determining national differences in economic development. To test the hypothesis, national IQs were calculated for 81 nations and economic development measured by real Gross Domestic Product at Purchasing Power Parity for 1998. The correlation between the two is .733, indicating that 54 per cent of the variance in GDP is attributable to the IQs of the populations.
The behavioral avoidance of people with facial disfigurement is well documented, but its psychological basis is poorly understood. Based upon a disease avoidance account of stigmatization, we conducted the first empirical test of whether facial disfigurement-naevus flammeus (a port wine stain) here-can trigger the same set of emotional and behavioral responses as a contagious disease (influenza). Ninety-eight participants contacted props, which they had seen used either by a healthy confederate or by a confederate simulating medical conditions affecting the face-birthmark and influenza. Behavioral avoidance (e.g., willingness to handle the prop) and facial display of disgust were recorded across five levels of prop contact varying from no contact to contact with the mouth. Behavioral avoidance and disgust displays, especially with oral contact, were equivalent in the birthmark and influenza conditions, with both significantly exceeding reactions to the healthy confederate. These results support the theory that humans have an evolved predisposition to avoid individuals with disease signs, which is mediated by the emotion of disgust. This implicit avoidance occurs even when they know explicitly that such signs-the birthmark here-result from a noncontagious condition.
Recent studies suggest that pathogen-related factors may contribute to systematic variation in women's preferences for masculinity in men's faces. However, there is very little evidence for similar correlations between pathogen-related factors and women's preferences for masculinity in other domains (e.g., men's voices or bodies). Consequently, we conducted a series of studies to examine whether pathogen disgust (assessed using Tybur et al's Three Domains of Disgust Scale) predicts individual differences in women's preferences for masculine characteristics in men's voices, bodies, and faces. We also tested if pathogen disgust predicts individual differences in measures of women's actual mate choices in the same way. We observed positive correlations between women's pathogen disgust and their preferences for masculinity in men's voices (Study 1) and faces and bodies (Study 2). We also observed positive correlations between women's pathogen disgust and their masculinity ratings of both their current and ideal romantic partners (Study 3). Each of these correlations was independent of the possible effects of women's sexual and moral disgust. Together, these findings suggest that individual differences in pathogen disgust predict individual differences in women's masculinity preferences across multiple domains and may also predict individual differences in their actual mate choices.
Eusociality is characterised by overlapping adult generations, cooperative brood care, and more or less nonreproductive workers or helpers. The most extreme cases of eusocially are species with highly specialised, permanently sterile castes of workers and soldiers. This review begins with an evaluation of the various hypotheses proposed to explain the evolution of eusociality in Hymenoptera and Isoptera. A comparative analysis of preconditions that are important for the evolution of insect eusociality follows. Finally, the occurrence of these preconditions is surveyed among vertebrates as a test of their generality. The crucial preconditions are shown to be similar in eusocial insects and eusocial-like vertebrates, eg naked mole-rat Heterocephalus glaber. No single trait can explain the evolution of eusociality: 2 conditions crucial for the evolution of eusociality are parental care (including the defence and feeding of offspring in a nest or other protected cavity), and low success of young adults or solitary pairs that attempt to reproduce.-from Author
Several theories suggest that religion evolved because it enhanced group cooperation; those individuals who professed a common religious belief cooperated better and therefore enhanced their individual fitness. The present experiment tested this hypothesis by asking participants to assess personality characteristics of unknown individuals who either wore a cross pendant, a symbol of Christianity, or a plain chain, using the Evaluation Of Others Questionnaire (EOOQ). The results indicated that participants who scored high on the Doctrinal Orthodoxy subscale of the Religious Orientation Scales gave greater scores to those wearing the cross pendant on the Kindness/Morality subscale of the EOOQ. This result is consistent with others that reported greater cooperation in economic games. However, here, we show that there does not need to be a competitive environment in order to reveal the increased assessment of kindness and morality, suggesting a potential mechanism for the enhanced cooperation seen in the competitive economic games. (PsycINFO Database Record (c) 2014 APA, all rights reserved)
In approximately 3.2% of bird species individuals regularly forgo the opportunity to breed independently and instead bree cooperatively with other conspecifics, either as non–reproductive ‘helpers’ or as co–breeders. The traditional explanatio for cooperative breeding is that the opportunities for breeding independently are limited owing to peculiar features of th specie's breeding ecology. However, it has proved remarkably difficult to find any common ecological correlates of cooperativ breeding in birds. This difficulty has led to the ‘life history hypothesis’, which suggests that the common feature of cooperativel breeding birds is their great longevity, rather than any particular feature of their breeding ecology. Here, we use a comparativ method to test the life history hypothesis by looking for correlations between life history variation and variation in th frequency of cooperative breeding. First, we find that cooperative breeding in birds is not randomly distributed, but concentrate in certain families, thus supporting the idea that there may be a common basis to cooperative breeding in birds. Second, increase in the level of cooperative breeding are strongly associated with decreases in annual adult mortality and modal clutch size.
Third, the proportion of cooperatively breeding species per family is correlated with a low family–typical value of annua mortality, suggesting that low mortality predisposes cooperative breeding rather than vice versa. Finally, the low rate o mortality typically found in cooperatively breeding species is associated with increasing sedentariness, lower latitudes and decreased environmental fluctuation. We suggest that low annual mortality is the key factor that predisposes avian lineage to cooperative breeding, then ecological changes, such as becoming sedentary, further slow population turnover and reduc opportunities for independent breeding. As the traditional explanation suggests, the breeding habitat of cooperatively breedin species is saturated, but this saturation is not owing to any peculiar feature of the breeding ecology of cooperative breeders.
Rather, the saturation arises because the local population turnover in these species is unusually slow, as predicted by th life history hypothesis.
Observational studies have suggested that with time, some diseases result in a characteristic odor emanating from different sources on the body of a sick individual. Evolutionarily, however, it would be more advantageous if the innate immune response were detectable by healthy individuals as a first line of defense against infection by various pathogens, to optimize avoidance of contagion. We activated the innate immune system in healthy individuals by injecting them with endotoxin (lipopolysaccharide). Within just a few hours, endotoxin-exposed individuals had a more aversive body odor relative to when they were exposed to a placebo. Moreover, this effect was statistically mediated by the individuals' level of immune activation. This chemosensory detection of the early innate immune response in humans represents the first experimental evidence that disease smells and supports the notion of a "behavioral immune response" that protects healthy individuals from sick ones by altering patterns of interpersonal contact.
The authors develop a conceptual model of how the congruence of political ideology and persuasive appeals enhances sustainable behaviors. In study 1, persuasive appeals consistent with individualizing and binding moral foundations were developed to enhance liberal and conservative recycling. In study 2, individualizing and binding appeals were tested on actual recycling behavior using a longitudinal field study to demonstrate the effectiveness of messages congruent with the moral foundations of liberals and conservatives. Study 3 demonstrated that enhanced fluency represents the underlying psychological process that mediates the relationship between message congruence and intentions. Moreover, study 3 established that spillover effects resulting from increased intentions to engage in sustainable disposition behavior enhance intentions to engage in sustainable acquisition and consumption behaviors. Finally, study 4 ruled out potential message confounds to demonstrate the robustness of the findings. Practical implications for marketers and public policy officials interested in increasing sustainable behaviors are offered.
Does Latin America exist?
Latin American studies centers (like African, or Middle Eastern or West European studies centers) are based on the assumption that Latin America (and Africa, the Middle East, etc.) are more than arbitary geographic expressions: they define coherent cultural regions, having people with distinctive values and worldviews that make them think differently and behave differently from people of other cultures.
The most powerful challenge to this view currently comes from the rational choice school, whose practitioners occasionally mention the importance of cultural differences but whose models almost always ignore them, implicitly assuming that in a given situation all people will make the same “rational” choices regardless of cultural perspectives. But if major differences exist between the worldviews and motivations of people in different cultural zones, a rational choice model that applies to the United States may not accurately describe the behavior of people in other cultures.
The existence of meaningful cultural areas has been challenged on other grounds as well. Modernization theory focuses on the differences between “traditional” and “modern” societies, each of which are characterized by distinctive economic, political, social, and cultural institutions. This perspective tends to attribute any differences between Latin American and highly industrialized societies to differences in their levels of economic development: with economic development, these differences will tend to disappear. Differences between various “traditional” cultures tend to be ignored.
The usefulness of “Latin America” as a meaningful cultural boundary could also be disputed on various other grounds.
It is hypothesized that human faces judged to be attractive by people possess two features-averageness and symmetry-that promoted adaptive mate selection in human evolutionary history by way of production of offspring with parasite resistance. Facial composites made by combining individual faces are judged to be attractive, and more attractive than the majority of individual faces. The composites possess both symmetry and averageness of features. Facial averageness may reflect high individual protein heterozygosity and thus an array of proteins to which parasites must adapt. Heterozygosity may be an important defense of long-lived hosts against parasites when it occurs in portions of the genome that do not code for the essential features of complex adaptations. In this case heterozygosity can create a hostile microenvironment for parasites without disrupting adaptation. Facial bilateral symmetry is hypothesized to affect positive beauty judgments because symmetry is a certification of overall phenotypic quality and developmental health, which may be importantly influenced by parasites. Certain secondary sexual traits are influenced by testosterone, a hormone that reduces immunocompetence. Symmetry and size of the secondary sexual traits of the face (e.g., cheek bones) are expected to correlate positively and advertise immunocompetence honestly and therefore to affect positive beauty judgments. Facial attractiveness is predicted to correlate with attractive, nonfacial secondary sexual traits; other predictions from the view that parasite-driven selection led to the evolution of psychological adaptations of human beauty perception are discussed. The view that human physical attractiveness and judgments about human physical attractiveness evolved in the context of parasite-driven selection leads to the hypothesis that both adults and children have a species-typical adaptation to the problem of identifying and favoring healthy individuals and avoiding parasite-susceptible individuals. It is proposed that this adaptation guides human decisions about nepotism and reciprocity in relation to physical attractiveness.
We examined the relationship between Individualism/Collectivism and generalized social trust across 31 European nations participating in the European Social Survey. Using multilevel regression analyses, the current study provides the first empirical investigation of the effects of cultural norms of Individualism/Collectivism on generalized social trust while accounting for individuals' own cultural orientations within the same analysis. The results provide clear support for Yamagishi and Yamagishi's (1994) emancipation theory of trust, showing a significant and positive relationship between Individualism/Collectivism and generalized social trust, over and above the effect of a country's political history of communism and ethnic heterogeneity. Having controlled for individual effects of Individualism/Collectivism it is clear that the results of the current analysis cannot be reduced to an individual-level explanation, but must be interpreted within the context of macrosocial processes. We conclude by discussing potential mechanisms that could explain why national individualism is more likely to foster trust among people than collectivism.
A recent stream of influential research suggests that the inclusion of behavioral genetic models can further inform our understanding of political preferences and behaviors. But it has often remained unclear what these models mean, or how they might matter for the broader discourse in the political science literature. The initial wave of behavioral genetic research focused on foundational discovery, and has begun to outline the basic properties of genetic influence on political traits, while a second wave of research has begun to link genetic findings to broader aspects of political behaviors. In the introduction to this special issue, we explicate how genes operate, the most common forms of behavioral genetic analyses, and their recent applications toward political behaviors. In so doing, we discuss what these findings mean for political science, and describe how best to interpret them. We note potential limitations of behavioral genetic approaches and remain cautious against the overextension of such models. The five articles that follow strive to move beyond discovery and focus more on the integration of behavioral genetic models with mainstream theories of political behavior to analyze problems of interest to political scientists.
An emerging literature has documented differences in values and behavioral practices (including conformity) between frontiers (areas that were more recently settled) and areas with a longer history of settlement. However, so far there have been few tests of which mechanisms might contribute to the maintenance of such regional differences. The present study provides the first test of the hypothesis that differences in pathogen prevalence might underlie this regional variation. Specifically, the relationship between frontier settlement, pathogen prevalence, and nonconformist voting was explored. Date of statehood, a proxy for recency of settlement, was positively correlated with votes for third-party candidates, and this relationship was partially mediated by pathogen prevalence. Theoretical and practical implications are discussed.
Change over time in culture can appear among individuals and in cultural products such as song lyrics, television, and books. This analysis examines changes in pronoun use in the Google Books ngram database of 766,513 American books published 1960-2008. We hypothesize that pronoun use will reflect increasing individualism and decreasing collectivism in American culture. Consistent with this hypothesis, the use of first person plural pronouns (e.g., we, us) decreased 10% first person singular pronouns (I, me) increased 42%, and second person pronouns (you, your) quadrupled. These results complement previous research finding increases in individualistic traits among Americans.
The relationship between culture and language was examined across 39 languages spoken in 71 cultures. Correlations were computed across languages and cultures between the use of first- and second-person singular pronouns (e.g., "I" and "you") and global cultural dimensions such as Individualism, which were previously extracted in large-scale cross-cultural surveys. The personal pronouns were analyzed in terms of the number of first- and second-person singular pronouns and whether the pronouns can be dropped when used as the subject of a sentence in speech. Cultures with pronoun drop languages tended to be less Individualistic than those with nonpronoun drop languages. The number of personal pronouns correlated with some cultural dimensions that reflected different conceptions of the person. Personal deixis (person-indexing pronouns) may provide a window through which cultural practices can be investigated.
Previous research has indicated that females are more likely than males to endorse collectivistic values and religious conservatism. The present research investigated an evolutionary explanation for these sex differences. More specifically, the sex differences in social conservatism may be due to variation in the behavioral immune system (BIS). The BIS is a set of psychological mechanisms that are proposed to be evolved solutions to disease threat. Four studies were conducted to examine this evolutionary explanation. In Study 1, BIS measures (e.g., disgust sensitivity) fully mediated sex differences in collectivism. This effect was specific to sexual disgust (Study 2). In Studies 3 and 4, the effect was extended to other forms of social conservatism (i.e., religious conservatism) and measures of the BIS. Together, these results suggest that sex differences in collectivism and religious conservatism may be explained in part by sex differences in the BIS.
Examines the implications of one species affecting another species via the impact of a parasite or pathogen borne in common. Protection against pathogenic parasites may be achieved, primarily by preempting resources by more benign parasitic species. Other forms of protection involve physical barriers or antibiotics generated by symbionts. Parasites can mediate in the exploitation of resources. Evolutionary implications are discussed, eg selection pressures acting on host-parasite interactions, diversification and speciation mediated by parasites, and metabolic and genetic integration with parasites. -P.J.Jarvis
Dispersal ability has been hypothesized to reduce intraspecific differentiation by homogenizing populations. On the other hand, long-distance dispersers may have better opportunities to colonize novel habitats, which could result in population divergence. Using direct estimates of natal and breeding dispersal distances, we investigated the relationship between dispersal distances and: (i) population differentiation, assessed as subspecies richness; (ii) ecological plasticity, assessed as the number of habitats used for breeding; and (iii) wing size, assessed as wing length. The number of subspecies was negatively correlated with dispersal distances. This was the case also after correcting for potential confounding factors such as migration and similarity due to common ancestry. Dispersal was not a good predictor of ecological plasticity, suggesting that long-distance dispersers do not have more opportunities to colonize novel habitats. Residual wing length was related to natal dispersal, but only for sedentary species. Overall, these results suggest that dispersal can have a homogenizing effect on populations and that low dispersal ability might promote speciation.
Determining what percentage of a given society believes in God - or doesn't - is fraught with methodological hurdles. First: low response rates; most people do not respond to surveys, and response rates of lower than 50 percent cannot be generalized to the wider society. Second: nonrandom samples. If the sample is not randomly selected - that is, every member of the given population has an equal chance of being chosen - it is nongeneralizable. Third: adverse political/cultural climates. In totalitarian countries where atheism is governmentally promulgated and risks are present for citizens viewed as disloyal, individuals will be reluctant to admit that they do believe in God. Conversely, in societies where religion is enforced by the government and risks are present for citizens viewed as nonbelievers, individuals will be reluctant to admit that they don't believe in Allah, regardless of whether anonymity is “guaranteed. ” Even in democratic societies without governmental coercion, individuals often feel that it is necessary to say that are religious, simply because such a response is socially desirable or culturally appropriate. For example, the designation “atheist ” is stigmatized in many societies; even when people directly claim to not believe in God, they still eschew the self-designation of “atheist. ”
Americans' health improved dramatically over the 20th century. Public health programs for disease and injury prevention were responsible for much of this advance. Over the century, America's public health system grew dramatically in scientific expertise and political authority. As the disease burden of the old scourges of infection, infant mortality, and dietary deficiencies began to lift, public health's mandate expanded to take on new health threats, such as those resulting from a changing workplace, the rise of the automobile and chronic conditions caused by smoking, diet, and other lifestyle and environmental factors. Public health's successes become part of everyday life, a fact already apparent early in the last century, when C. E. A. Winslow noted that the lives saved and healthy years extended were the "silent victories" of public health. In its exploration of ten major public health issues addressed in the 20th century, this book traces the discoveries, practices, and programs in ten areas of pubic health-infection disease control, vaccination, food safety, maternal and infant health, nutrition, occupational health, family planning, oral health, vehicular safety, cardiovascular disease prevention, and tobacco control-coupled with chapters highlighting key issues or conflicts that shaped public health action. The book concludes with a look toward the future challenges for public health.
This study investigated the relationship between culture, structural aspects of the nuclear and extended family, and functional aspects of the family, that is, emotional distance, social interaction, and communication, as well as geographical proximity. The focus was on the functional aspects of family, defined as members of the nuclear family (mother, father, and their children) and the extended family (grandmother/grandfather, aunt/uncle, cousins). Sixteen cultures participated in this study, with a total number of 2587 participants. The first hypothesis, that the pattern of scores on the psychological measures and the behavioral outcomes are similar across cultures, an indication of cultural universality, was supported. The second hypothesis, that functional relations between members of the nuclear family and their kin are maintained in high-affluent and low-affluent cultures, and that differences in functional relationships in high-and low-affluent cultures are a matter of degree, was also supported by the findings. The results suggest that it is less meaningful in cross-cultural family studies to ask questions about the structure of the family, than to ask about the functional relationships between members of the nuclear family and their kin. In looking only at the nuclear family, one focuses only on those residing in the household, but ignores those important members of the extended family who may reside nearby and their significant relationships with the members of the nuclear family.
Although outlawed in many states, serpent handling remains an active religious practice-and one that is far more stereotyped than understood. Ralph W. Hood, Jr. and W. Paul Williamson have spent fifteen years touring serpent-handling churches in Alabama, Georgia, Tennessee, Kentucky, North Carolina, and West Virginia, conducting scores of interviews with serpent handlers, and witnessing hundreds of serpent-handling services. In this illuminating book they present the most in-depth, comprehensive study of serpent handling to date. Them That Believe not only explores facets of this religious practice-including handling, preaching, and the near-death experiences of individuals who were bitten but survived-but also provides a rich analysis of this phenomenon from historical, social, religious, and psychological perspectives.
It is well accepted that disgust is an emotion whose main function is to motivate away from cues of disease or potential contamination. Although this adaptive problem is one that both men and women face, women tend to have heightened disgust sensitivity and higher frequency of psychopathologies like obsessive-compulsive disorder that have heightened disgust sensitivity as a core symptom. Women have faced unique selection pressures such as pregnancy, changes in immunity over the menstrual cycle, higher obligate parental investment, and heavier disease burden from sexually transmitted infection that have contributed to their increased disgust sensitivity compared to men. First, this chapter outlines the development of a theoretical framework around the evolution and function of disgust. Next, it reviews sex differences in disgust sensitivity as well as the modulation of disgust sensitivity. Finally, sexual disgust and recent work investigating how disgust and sexual arousal reciprocally influence one another are reviewed including the contribution of disgust to sexual disorders and expression.
In this paper I explore the psychology of ritual performance and present a simple graphical model that clarifies several issues in William Irons's theory of religion as a "hard-to-fake" sign of commitment. Irons posits that religious behaviors or rituals serve as costly signals of an individual's commitment to a religious group. Increased commitment among members of a religious group may facilitate intra-group cooperation, which is argued to be the primary adaptive benefit of religion. Here I propose a proximate explanation for how individuals are able to pay the short-term costs of ritual performance to achieve the long-term fitness benefits offered by religious groups. The model addresses three significant problems raised by Irons's theory. First, the model explains why potential free-riders do not join religious groups even when there are significant net benefits that members of religious groups can achieve. Second, the model clarifies how costly a ritual must be to achieve stability and prevent potential free-riders from joining the religious group. Third, the model suggests why religious groups may require adherents to perform private rituals that are not observed by others. Several hypotheses generated from the model are also discussed.
Humans have borrowed plants' chemical 'recipes' for evolutionary survival for use in cuisine to combat foodborne microorganisms and to reduce food poisoning.
There is increasing research evidence that religious involvement is associated both cross-sectionally and prospectively with better physical health, better mental health, and longer survival. These relationships remain substantial in size and statistically significant with other risk and protective factors for morbidity and mortality statistically controlled. In this article, we review the social and psychological factors that have been hypothesized to explain the health-promoting effects of religious involvement. The four potential psychosocial mechanisms that have received empirical attention are health practices, social support, psychosocial resources such as self-esteem and self-efficacy, and belief structures such as sense of coherence. Evidence concerning these potential mediators is mixed and inconsistent, suggesting there is more to be learned about the pathways by which religion affects health. Other possible explanations for the salubrious effects of religious involvement on health and longevity are discussed.
Rates of scientific and technological innovation vary widely across cultures, but why? Given the previously documented effects of disease threat on cultural values and traits that inhibit innovation, this variation may be due, at least in part, to regional variation in the prevalence of disease-causing pathogens. Five country-level measures of innovation were used to investigate this hypothesis. Preliminary results revealed that pathogen prevalence was significantly associated with all five measures of innovation. Further analyses revealed that pathogen prevalence significantly predicted innovation when statistically controlling for other purported causes of cross-cultural variation in innovation, such as education, wealth, and population structure. Finally, mediational analyses revealed that the effect of disease prevalence on innovation was mediated by levels of collectivism and conformity. These results demonstrate that the previously documented impact of disease threat on cultural value systems may have downstream consequences for scientific and technological innovation.
Based on the reasoning that religious groups evidence intergroup processes that can create prejudice, two studies examined the relation between religiosity and attitudes toward religious and non-religious others. In both studies, among more religious individuals, attitudes toward religious others were very positive and attitudes toward non-religious others were quite negative. These relations emerged on all measures of traditional religiosity used. Some prejudice against religious others existed among less religious individuals, but it was less pronounced and less pervasive than the prejudice of more religious people. It is suggested that intergroup processes such as competition between religious groups for resources or value promotion likely foster prejudice against religious outgroup members, perhaps irrespective of personal religious orientation.
The empirical study of the causes and consequences of political democracy has been the subject of considerable research. Yet cumulative development of this research is hampered by the controversial aspects and limitations of the existing indices of political democracy. These issues concern the validity of the indicators, the unknown reliability, and the limited sample and temporal coverage of these indices. After a discussion of these issues, a revised index of political democracy that overcomes some of these limitations is presented. The indicators of the revised index are analyzed by means of confirmatory factor analysis and the reliability of the measure is discussed. The index is generally better than existing measures in reliability, sample size, and temporal coverage; but the remaining limitations of the index are reviewed. The moderate to high correlations of this index with other democracy indices support its external validity. Yet, the differences in empirical results possible by using different indices are demonstrated. Finally, there are two appendices. The first provides the technical details of the confirmatory factor analysis. The second appendix lists the values of the political democracy index.
A simulation model was constructed to investigate the evolution of reproductive isolation between habitat specialists when disruptive selection was applied to habitat preference. Disruptive selection favored individuals that selected either end of a gradient of nine habitat patch types. Habitat preference was assumed to be controlled by four additive unlinked loci. In different simulations it was assumed that habitat preference pleiotropically produced varying levels of partial assortative mating between individuals with similar habitat preference. The simulations indicated a strong interaction between the processes of disruptive selection and habitat-based assortative mating. Moderate levels of either disruptive selection or habitat-based assortative mating, when operating alone, resulted in the evolution of little or no reproductive isolation between the subpopulations genetically disposed to utilize each of the selected habitats. When these two factors were applied together there was a marked increase in the development of reproductive isolation that could not be explained by the additive effects of each factor. The genetic mechanism producing this interaction appears to be the reversal of an antagonistic interaction between the processes of selection and recombination that typically interferes with the evolution of reproductive isolation under sympatric conditions.
Using Chrysomela confluens (Coleoptera: Chrysomelidae), the authors examined the hypothesis that naturally occurring hybrid zones between two cottonwood species are "sinks' or centers of insect abundance. Over a 3-yr period, 94% of the C. confluens population was restricted to a 13-km hybrid zone, which represents <3% of the cottonwood population. Of several potential mechanisms tested, expanded host phenology in the hybrid zone, relative to pure zones, best explained the distribution of C. confluens which is independent upon newly flushed leaves for optimal growth and reproduction. The hybrid zone is a superior beetle habitat because: 1) early leaf flush in the hybrid zone provides the first source of food for beetles in spring and 2) staggered leaf phenologies in the hybrid zone allow beetles to shift onto newly flushed Fremont trees as foliage of sympatric hybrid and narrowleaf trees declines in quality. This shift by ovipositing females can result in a 600% increase in fecundity relative to nonshifting females. The hybrid zone is a "phenologial sink' that increases beetle fecundity and leads to chronically high herbivory year after year. Because movement from the hybrid zone reduces fecundity, emigration into adjacent pure zones is likely hindered. -from Authors
Who is Steven Pinker and why has so much media fuss been made over his new book on the decline of violence in the Western world? He is a famous Harvard psychologist, initially specialising in language acquisition, in the wake of the even more celebrated Noam Chomsky, who postulated that humans everywhere have an innate cerebral capacity for developing grammar. Pinker, in a pair of influential books published by Penguin, picked up and developed the idea that human beings possess innate capacities, evolved over the very long duration, and concluded that the brain contains scores of specialised processing tools working via modules—something like a Swiss Army knife.¹ Pinker’s work employs the findings of two generations of neurologists, animal and human ethologists and anthropologists who have rediscovered Human Nature.² This is a development with huge implications for historians, for it overturns the anti-scientific pretentions of humanists who claim that culture alone determines human actions, and that culture is everywhere unstable, constantly subject to change and transformation. Historians, as much as anybody, require a rough-and-ready idea of human nature in order to provide plausible explanations for behaviour in any era. The behavioural sciences (a broad grouping of disciplines—from classical psychology, sociology and anthropology, to human and animal ethology, and evolutionary psychology) provide a more disciplined approach to its study, a substantial improvement on the intuitive hunches on which historians have always relied. Not that Pinker’s claim of a modular brain has received the unanimous support of psychologists!³ However, those of his critics whose works I have encountered to date have tended to restrict their comments to Pinker’s modular brain thesis alone; much less fully explored or critiqued are the broader questions about human nature that flow from that thesis, especially the issue of what humans around the world have had in common throughout recorded history.⁴ After discussing only the salient points in what is a very big book, full of detail and discursive in argument, I will compare it to some of the recent work on the history of violence in Western Europe which explains this universal feature of human behaviour in specifically cultural terms—what I call the view from circa 1970. In the last pages I would like to point to the emergence of some empirical historical work, hopefully a harbinger of the future shape of behavioural history, no longer content to frame human behaviour in those cultural terms.
Replication of the Nisbett-Reaves test of the herding-culture-of-honor hypothesis fails to support expectations derived from
Nisbett's culture-of-honor theory. The theory predicts that violent culture has economic advantage in frontier areas with
herding economies, because there is a chronic threat of livestock theft. Nisbett and Reaves hypothesize that rural counties
in the South, where ecological conditions promote livestock herding will have especially high white non-Hispanic male homicide
rates. Our statistical analysis reproduces the mean homicide rates reported by previous research, but indicates that they
are artifacts of skewed distributions, unreliable estimates of homicide rates, and the failure to control for differences
in the distribution of white poverty.
Conventional wisdom holds that parasites evolve more rapidly than their hosts and are therefore locally adapted, that is, better at exploiting sympatric than allopatric hosts. We studied local adaptation in the insect-transmitted fungal pathogen Microbotryum violaceum and its host plant Silene latifolia. Infection success was tested in sympatric (local) and allopatric (foreign) combinations of pathogen and host from 14 natural populations from a metapopulation. Seedlings from up to 10 seed families from each population were exposed to sporidial suspensions from each of four fungal strains derived from the same population, from a near-by population (
This book seeks to explain the origins of religion using our knowledge of the evolution of cognition. Written by a cognitive anthropologist and psychologist, the book argues that religion is a by-product of human evolution just as the cognitive intervention, cultural selection, and historical survival of religion is an accommodation of certain existential and moral elements that have evolved in the human condition.
Parasites may impose stronger selection pressures on their hosts in the tropics compared to non-tropical climatic zones because parasite abundance is not reduced by the adverse environmental conditions of winter as at high latitudes. Furthermore, tropical parasites tend to be more host-specific than temperate zone parasites, and their effects on juvenile mortality of hosts is particularly strong. I tested indirectly whether tropical parasites have had stronger impact on their hosts by making a pairwise comparative study of host investment in anti-parasite defence. Closely related pairs of birds were used to test the prediction that investment in immune function should be greater in the tropics as compared to non-tropical zones. The circulating concentration of leukocytes in the blood was consistently higher in tropical bird species as compared to non-tropical ones. The relative size of the spleen for a given body size was significantly larger in tropical as compared to that of closely related non-tropical species. Interspecific differences in immune function between hosts in the tropics and non-tropical climate zones should affect divergence in host population dynamics, host population density and diversity, host life-history evolution, and the evolution of host sexuality and sexual selection.
The value of different mate choices may depend on the local pathogen ecology and on personal infection susceptibility: when there is a high risk of infection, choosing a healthy or immunocompetent mate may be particularly important. Frequency of childhood illness may act as a cue of the ecological and immunological factors relevant to mate preferences. Consistent with this proposal, we found that childhood illness – and frequency of diarrhea in particular – was positively correlated with preferences for exaggerated sex-typical characteristics in opposite-sex, but not same-sex, faces. Moreover, this relationship was stronger among individuals with poorer current health. These data suggest that childhood illness may play a role in calibrating adult mate preferences and have implications for theories of disease-avoidance psychology, life-history strategy and cross-cultural differences in mate preferences.
In two large samples (combined N = 31,045), we found a positive relationship between disgust sensitivity and political conservatism. This relationship held when controlling for a number of demographic variables as well as the “Big Five” personality traits. Disgust sensitivity was also associated with more conservative voting in the 2008 U.S. presidential election. In Study 2, we replicated the disgust sensitivity–conservatism relationship in an international sample of respondents from 121 different countries. Across both samples, contamination disgust, which reflects a heightened concern with interpersonally transmitted disease and pathogens, was most strongly associated with conservatism.
Comparative studies of democratization have produced two types of generalizations: those having nearly universal application and those applying to a range of countries within a region. In the first category are such arguments as the role of high levels of economic development in guaranteeing democratic sustainability, the centrality of political elites in establishing and terminating democracy, and deficits in rule of law and state capacity as the primary challenge to the quality and survival of new democracies. In the second category are contrasts between recent democratization in post-Socialist Europe versus Latin America and southern Europe—for example, in the relationship between democratization and economic reform and in the costs and benefits for democratic consolidation of breaking quickly versus slowly with the authoritarian past. The two sets of conclusions have important methodological implications for how comparativists understand generalizability and the emphasis placed on historical versus proximate causation.
This study evaluates the economic consequences of the successful eradication of hookworm disease from the American South. The hookworm-eradication campaign (c. 1910) began soon after (i) the discovery that a variety of health problems among Southerners could be attributed to the disease and (ii) the donation by John D. Rockefeller of a substantial sum to the effort. The Rockefeller Sanitary Commission (RSC) surveyed infection rates in the affected areas (eleven southern states) and found that an average of forty percent of school-aged children were infected with hookworm. The RSC then sponsored treatment and education campaigns across the region. Follow-up studies indicate that this campaign substantially reduced hookworm disease almost immediately. The sudden introduction of this treatment combines with the cross-area differences in pre-treatment infection rates to form the basis of the identification strategy. Areas with higher levels of hookworm infection prior to the RSC experienced greater increases in school enrollment, attendance, and literacy after the intervention. This result is robust to controlling for a variety of alternative factors, including differential trends across areas, changing crop prices, shifts in certain educational and health policies, and the effect of malaria eradication. No significant contemporaneous results are found for adults, who should have benefited less from the intervention owing to their substantially lower (prior) infection rates. A long-term follow-up of affected cohorts indicates a substantial gain in income that coincided with exposure to hookworm eradication. I also find evidence that eradication increased the return to schooling.