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The parasite-stress theory may be a general theory of culture and sociality

  • Corey L. Fincher (a1) and Randy Thornhill (a1)


In the target article, we presented the hypothesis that parasite-stress variation was a causal factor in the variation of in-group assortative sociality, cross-nationally and across the United States, which we indexed with variables that measured different aspects of the strength of family ties and religiosity. We presented evidence supportive of our hypothesis in the form of analyses that controlled for variation in freedom, wealth resources, and wealth inequality across nations and the states of the USA. Here, we respond to criticisms from commentators and attempt to clarify and expand the parasite-stress theory of sociality used to fuel our research presented in the target article.



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Alesina, A. & Giuliano, P. (2007) The power of the family. Discussion paper, No. 2132. Harvard Institute of Economic Research, Harvard University. Available at:
Archer, J. (2006) Cross-cultural differences in physical aggression between partners: a social role analysis. Personality and Social Psychology Review 10:133–53.
Barber, N. (2011) A cross-national test of the uncertainity hypothesis of religious belief. Cross-Cultural Research 45(3):318–33.
Berwick, D. M. (2003) Disseminating innovations in health care. Journal of the American Medical Association (JAMA) 289:1969–75.
Boyd, R. & Richerson, P. J. (1985) Culture and the evolutionary process. The University of Chicago Press.
Cashdan, E. (2001a) Ethnic diversity and its environmental determinants: Effects of climate, pathogens, and habitat diversity. American Anthropologist 103:968–91.
Cashdan, E. & Steele, M. (2010) Do pathogens and other risks promote ethnocentrism, xenophobia, and ethnic diversity? Unpublished paper presented at the annual meeting of the American Anthropological Association, New Orleans. November 17–21, 2010.
Cavalli-Sforza, L. & Feldman, M. (1981) Cultural transmission and evolution: A quantitative approach. Princeton University Press.
Curtis, V., de Barra, M. & Aunger, R. (2011) Disgust as an adaptive system for disease avoidance behaviour. Philosophical Transactions of the Royal Society B 366:389401.
DeBruine, L. M., Jones, B. C., Crawford, J. R., Welling, L. L. M. & Little, A. C. (2010) The health of a nation predicts their mate preferences: Cross-cultural variation in women's preferences for masculinized male faces. Proceedings of the Royal Society of London B 277(1692):2405–10.
DeBruine, L. M., Jones, B. C., Little, A. C., Crawford, J. R. & Welling, L. L. M. (2011) Further evidence for regional variation in women's masculinity preferences. Proceedings of the Royal Society of London B 278(1707):813–14.
Dethlefsen, L., McFall-Ngai, M. & Relman, D. A. (2007) An ecological and evolutionary perspective on human–microbe mutualism and disease. Nature 449:811–18.
Duncan, L. A. & Schaller, M. (2009) Prejudicial attitudes toward older adults may be exaggerated when people feel vulnerable to infectious disease: Evidence and implications. Analyses of Social Issues and Public Policy 9:97115.
Durham, W. H. (1991) Coevolution: Genes, culture and human diversity. Stanford University Press.
Eppig, C., Fincher, C. L. & Thornhill, R. (2010) Parasite prevalence and the worldwide distribution of cognitive ability. Proceedings of the Royal Society of London B. 277(1701):3801–808.
Eppig, C., Fincher, C. L. & Thornhill, R. (2011) Parasite prevalence and the distribution of intelligence among the states of the USA. Intelligence 39:155–60.
Fincher, C. L. (2011) The effects of parasite stress on international relations and trade flow. Paper presented at the Annual Meeting of the Society for Cross-Cultural Research, Charleston, South Carolina, February 16–19, 2011.
Fincher, C. L. & Thornhill, R. (2008a) A parasite-driven wedge: Infectious diseases may explain language and other biodiversity. Oikos 117:1289–97.
Fincher, C. L. & Thornhill, R. (2008b) Assortative sociality, limited dispersal: Infectious disease and the genesis of the global patterns of religious diversity. Proceedings of the Royal Society of London, B: Biological Sciences 275:2587–94.
Fincher, C. L., Thornhill, R., Murray, D. R. & Schaller, M. (2008) Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism. Proceedings of the Royal Society, B 275:1279–85.
Freeland, W. J. (1976) Pathogens and the evolution of primate sociality. Biotropica 8:1224.
Gangestad, S. W. & Buss, D. M. (1993) Pathogen prevalence and human mate preferences. Ethology and Sociobiology 14:8996.
Gangestad, S. W., Haselton, M. G. & Buss, D. M. (2006a) Evolutionary foundations of cultural variation: Evoked culture and mate preferences. Psychological Inquiry 17:7595.
Gelfand, M. J., Bhawuk, D. P. S., Nishii, L. H. & Bechtold, D. J. (2004) Individualism and collectivism. In: Culture, leadership, and organizations: The GLOBE study of 62 societies, ed. House, R. J., Hanges, P. J., Javidan, M., Dorfman, P. W. & Gupta, V., pp. 437512. Sage.
Hamilton, W. D. & Zuk, M. (1982) Heritable true fitness and bright birds: A role for parasites? Science 218:384–87.
Hood, R. W. Jr., & Williamson, W. P. (2008) Them that believe: The power and meaning of the Christian serpent-handling tradition. University of California Press.
Inbar, Y., Pizarro, D. A. & Bloom, P. (2009) Conservatives are more easily disgusted than liberals. Cognition and Emotion 23:714–25.
Jencks, S. F., Huff, E. D. & Cuerdon, T. (2003) Change in the quality of care delivered to Medicare beneficiaries, 1998–1999 to 2000–2001. Journal of the American Medical Association (JAMA) 289:305–12.
Jost, J. T., Federico, C. M. & Napier, J. L. (2009) Political ideology: Its structure, functions, and elective affinities. Annual Review of Psychology 60:307–37.
Kurzban, R. & Leary, M. R. (2001) Evolutionary origins of stigmatization: The functions of social exclusion. Psychological Bulletin 127(2):187208.
Letendre, K., Fincher, C. L. & Thornhill, R. (2010) Does infectious disease cause global variation in the frequency of intrastate armed conflict and civil war? Biological Reviewes 85:669–83.
Letendre, K., Fincher, C. L. & Thornhill, R. (in press) Parasite stress may cause non-state wars, revolutions and coups, terrorism, and the absence of peace across the world. In: The Oxford Handbook of Evolutionary Perspectives on Violence, Homicide, and War, ed. Shackelford, T. & Weekes-Shackelford, V.. Oxford University Press.
Little, A. C., DeBruine, L. M. & Jones, B. C. (2011) Exposure to visual cues of pathogen contagion changes preferences for masculinity and symmetry in opposite-sex faces. Proceedings of the Royal Society of London B 278:2032–39.
Low, B. S. (1988) Pathogen stress and polygyny in humans. In: Human reproductive behavior: A Darwinian perspective, ed. Betzig, L., Mulder, M. Borgerhoff & Turke, P., pp. 115–27. Cambridge University Press.
Low, B. S. (1990) Marriage systems and pathogen stress in human societies. American Zoologist 30:325–39.
Lumsden, C. J. & Wilson, E. O. (1981) Genes, mind and culture: The coevolutionary process. Harvard University Press.
Mace, R. & Pagel, M. (1994) The comparative method in anthropology. Current Anthropology 35:549–64.
Mortensen, C. R., Becker, D. V., Ackerman, J. M., Neuberg, S. L. & Kenrick, D. T. (2010) Infection breeds reticence: the effects of disease salience on self-perceptions of personality and behavioral avoidance tendencies. Psychological Science 21:440–47.
Murdock, G. P. (1949) Social structure. MacMillan.
Murray, D. R. & Schaller, M. (2010) Historical prevalence of infectious diseases within 230 geopolitical regions: A tool for investigating origins of culture. Journal of Cross-Cultural Psychology 41:99108.
Murray, D. R., Trudeau, R. & Schaller, M. (2011) On the origins of cultural differences in conformity: Four tests of the pathogen prevalence hypothesis. Personality and Social Psychology Bulletin 37:318–29.
Nisbett, R. E., Peng, K., Choi, I. & Norenzayan, A. (2001) Culture and systems of thought: Holistic vs. analytic cognition. Psychological Review 108:291310.
Oaten, M., Stevenson, R. J. & Case, T. I. (2009) Disgust as a disease-avoidance mechanism. Psychological Bulletin 135:303–21.
Oishi, S. (2010) The psychology of residential mobility: Implications for the self, social relationships, and well-being. Perspectives on Psychological Science 5:521.
Park, J. H., Faulkner, J. & Schaller, M. (2003) Evolved disease-avoidance processes and contemporary anti-social behavior: Prejudicial attitudes and avoidance of people with physical disabilities. Journal of Nonverbal Behavior 27:6587.
Park, J. H., Schaller, M. & Crandall, C. S. (2007) Pathogen-avoidance mechanisms and the stigmatization of obese people. Evolution and Human Behavior 28:410–14.
Paul, G. (2009) The chronic dependence of popular religiosity upon dysfunctional psychosociological conditions. Evolutionary Psychology 7:398441. Available at:
Pemstein, D., Meserve, S. A. & Melton, J. (2010) Democratic compromise: A latent variable analysis of ten measures of regime type. Political Analysis. 18:426–49
Price-Smith, A. T. (2002) The health of nations: Infectious disease, environmental change, and their effects on national security and development. MIT Press.
Quinlan, R. J. (2007) Human parental effort and environmental risk. Proceedings of the Royal Society, B 274:121–25.
Rees, T. (2009) Is personal insecurity a cause of cross-national differences in the intensity of religious belief? Journal of Religion and Society 11. Available at:
Sachs, J. & Malaney, P. (2002) The economic and social burden of malaria. Nature 415:680–85.
Schaller, M. C., Miller, G. E., Gervais, W. M., Yager, S. & Chen, E. (2010) Mere visual perception of other people's disease symptoms facilitates a more aggressive immune response. Psychological Science 21:649–52.
Schaller, M. & Park, J. H. (2011) The behavioral immune system (and why it matters). Current Directions in Psychological Science 20:99103.
Schwartz, S. H. (1992) Universals in the content and structures of values: Theoretical advances and empirical tests in 20 countries. Advances in Experimental Social Psychology 25:165.
Schwartz, S. H. (2004) Mapping and interpreting cultural differences around the world. In: Comparing cultures: Dimensions of culture in a comparative perspective, ed. Vinkin, H., Soeters, J. & Ester, P., pp. 4373. Brill.
Solt, F. (2009) Standardizing the world income inequality database. Social Science Quaterly 90:232342.
Solt, F., Habel, P. & Grant, J. T. (2011) Economic inequality, relative power, and religiosity. Social Science Quaterly 92:448–65.
Thornhill, R. & Fincher, C. L. (2011) Parasite stress promotes homicide and child maltreatment. Philosophical Transactions of the Royal Society B 366:3466–77.
Thornhill, R. & Fincher, C. L. (in preparation) Parasites, history, and values across the world. Book-length manuscript.
Thornhill, R., Fincher, C. L. & Aran, D. (2009) Parasites, democratization, and the liberalization of values across contemporary countries. Biological Reviews 84:113–31.
Thornhill, R., Fincher, C. L., Murray, D. R. & Schaller, M. (2010) Zoonotic and non-zoonotic diseases in relation to human personality and societal values: Support for the parasite-stress model. Evolutionary Psychology 8:151–69.
Thornhill, R. & Gangestad, S. W. (2006) Facial sexual dimorphism, developmental stability and susceptibility to disease in men and women. Evolution and Human Behavior 27:131–44.
Thornhill, R. & Gangestad, S. W. (2008) The evolutionary biology of human female sexuality. Oxford University Press.
Thornhill, R. & Palmer, C. T. (2004) Evolutionary life history perspective on rape. In: Evolutionary psychology, public policy and personal decisions, ed. Crawford, C. & Salmon, C., pp. 249–74. Erlbaum.
Tybur, J. M., Merriman, L. A., Caldwell Hooper, A. E., McDonald, M. M. & Navarrete, C. D. (2010) Extending the behavioral immune system to political psychology: Are political conservatism and disgust sensitivity really related? Evolutionary Psychology 8:599616.
Uskul, A. K., Kitayama, S. & Nisbett, R. E. (2008) Ecocultural basis of cognition: Farmers and fishermen are more holistic than herders. Proceedings of the National Academy of Sciences USA 105:8552–56.
Van de Vliert, E. (2009) Climate, affluence, and culture. Cambridge University Press.
Van de Vliert, E. (2011b) Climato-economic origins of variation in ingroup favoritism. Journal of Cross-Cultural Psychology 42(3):494515.
Vigil, J. M. (2009) A socio-relational framework of sex differences in the expression of emotion. Behavioral and Brain Sciences 32:375428.
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