Pathogen prevalence is associated with cultural changes in gender equality

  • Nature Human Behaviour volume 1, Article number: 0003 (2016)
  • doi:10.1038/s41562-016-0003
  • Download Citation


Gender equality has varied across time, with dramatic shifts in countries such as the United States in the past several decades. Although differences across societies and changes within societies in gender equality have been well documented, the causes of these changes remain poorly understood. Scholars have posited that such shifts have been driven by specific events (such as Title IX and Roe versus Wade), broader social movements (such as feminism and women’s liberation) or general levels of social development (for example, modernization theory1). Although these factors are likely to have been partly responsible for temporal variations in gender equality, they provide fairly intermediate explanations void of a comprehensive framework. Here, we use an ecological framework to explore the role of key ecological dimensions on change in gender equality over time. We focus on four key types of ecological threats/affordances that have previously been linked to cultural variations in human behaviour as potential explanations for cultural change in gender equality: infectious disease, resource scarcity, warfare and climatic stress. We show that decreases in pathogen prevalence in the United States over six decades (1951–2013) are linked to reductions in gender inequality and that such shifts in rates of infectious disease precede shifts in gender inequality. Results were robust, holding when we controlled for other ecological dimensions and for collectivism and conservative ideological identification (indicators of more broadly traditional cultural norms and attitudes). Furthermore, the effects were partially mediated by reduced teenage birth rates (a sign that people are adopting slower life history strategies), suggesting that life history strategies statistically account for the relationship between pathogen prevalence and gender inequality over time. Finally, we replicated our key effects in a different society, using comparable data from the United Kingdom over a period of seven decades (1945–2014).

Additional access options:

Already a subscriber?  Log in  now or  Register  for online access.


  1. 1.

    & Rising Tide: Gender Equality and Cultural Change Around the World (Cambridge Univ. Press, 2003).

  2. 2.

    & in Advances in Culture and Psychology Vol. 3 (eds Gelfand, M. J. et al. ) 78–123 (Oxford Univ. Press, 2014).

  3. 3.

    Socioecological psychology. Annu. Rev. Psychol. 65, 581–609 (2014).

  4. 4.

    & The Parasite-Stress Theory of Values and Sociality: Infectious Disease, History and Human Values Worldwide (Springer, 2014).

  5. 5.

    Climato-economic habitats support patterns of human needs, stresses, and freedoms. Behav. Brain Sci. 36, 465–480 (2013).

  6. 6.

    & Parasite stress promotes homicide and child maltreatment. Phil. Trans. R. Soc. B 366, 3466–3477 (2011).

  7. 7.

    & Social structure, infectious diseases, disasters, secularism, and cultural change in America. Psychol. Sci. 26, 311–324 (2015).

  8. 8.

    & Socio-ecological changes are linked to changes in the prevalence of contempt over time. Behav. Brain Sci. (in the press).

  9. 9.

    & The behavioral immune system (and why it matters). Curr. Dir. Psychol. Sci. 20, 99–103 (2011).

  10. 10.

    , & & On the origins of cross-cultural differences in conformity: four tests of the pathogen prevalence hypothesis. Pers. Soc. Psychol. Bull. 37, 318–329 (2011).

  11. 11.

    & Threat(s) and conformity deconstructed: perceived threat of infectious disease and its implications for conformist attitudes and behavior. Eur. J. Soc. Psychol. 42, 180–188 (2012).

  12. 12.

    Frontiers, germs, and non-conformist voting. J. Cross-Cult. Psychol. 44, 832–837 (2013).

  13. 13.

    , & Pathogens and politics: further evidence that parasite prevalence predicts authoritarianism. PLoS ONE 8, e62275 (2013).

  14. 14.

    & Pathogens, personality, and culture: disease prevalence predicts worldwide variability in sociosexuality, extraversion, and openness to experience. J. Pers. Soc. Psychol. 95, 212–221 (2008).

  15. 15.

    et al. Differences between tight and loose cultures: a 33-nation study. Science 332, 1100–1104 (2011).

  16. 16.

    , & Evolutionary foundations of cultural variation: evoked culture and mate preferences. Psychol. Inq. 17, 75–95 (2006).

  17. 17.

    , & Parasites, democratization, and the liberalization of values across contemporary countries. Biol. Rev. 84, 113–131 (2009).

  18. 18.

    , & Vulnerability to disease as a predictor of faster life history strategies. Adapt. Hum. Behav. Physiol. 2, 116–133 (2016).

  19. 19.

    , & in The Handbook of Evolutionary Psychology 2nd edn, Vol. 1 (ed. Buss, D. M.) Ch. 2 (Wiley, 2015).

  20. 20.

    Sources of regional variation in social capital in the United States: frontiers and pathogens. Evol. Behav. Sci. 8, 77–85 (2014).

  21. 21.

    et al. When the economy falters do people spend or save? Responses to resource scarcity depend on childhood environments. Psychol. Sci. 24, 197–205 (2013).

  22. 22.

    & Women in the United States Congress, 1917-2004: Biographical and Committee Assignment Information and Listings by State and Congress. Report RL30261 (Congressional Research Service, 2014).

  23. 23.

    , & Male and female pronoun use in US books reflects women’s status, 1900–2008. Sex Roles 67, 488–493 (2012).

  24. 24.

    & Gallup Poll Social Series: Work and Education (Gallup, 2014).

  25. 25.

    , & National and State Patterns of Teen Births in the United States, 1940–2013 Vol. 63, No. 4 (National Vital Statistics Reports, National Center for Health Statistics, 2014).

  26. 26.

    & Trends in teenage pregnancy in England and Wales: how can we explain them? J. R. Soc. Med. 92, 277–282 (1999).

  27. 27.

    Nonlinear time series models in economics. J. Econ. Surv. 5, 215–242 (1991).

  28. 28.

    & Does the Box–Cox Transformation Help in Forecasting Macroeconomic Time Series? (Univ. Library of Munich, 1991).

Download references


This research was supported by the Insight grant no. 435-2014-0685 from the Social Sciences and Humanities Research Council of Canada (to I.G.) and by a grant from the John Templeton Foundation ‘Prospective Psychology Stage 2: A Research Competition to Martin Seligman’ (sub-grant awarded to I.G.). The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation. Neither funder had any role in the study design, the data collection and analysis, the decision to publish or the preparation of the manuscript.

Author information


  1. Department of Psychology, Arizona State University, 950 S. McAllister, Tempe, Arizona 85287, USA

    • Michael E. W. Varnum
  2. Department of Psychology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L3G1, Canada

    • Igor Grossmann


  1. Search for Michael E. W. Varnum in:

  2. Search for Igor Grossmann in:


M.E.W.V. developed the original study concept. M.E.W.V. and I.G. gathered and analysed the data and drafted and revised the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Michael E. W. Varnum.

Supplementary information

PDF files

  1. 1.

    Supplementary information

    Supplementary Methods, Supplementary Results, Supplementary Figures 1–5, Supplementary Tables 1,2 and Supplementary References