Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

War increases religiosity


Does the experience of war increase people’s religiosity? Much evidence supports the idea that particular religious beliefs and ritual forms can galvanize social solidarity and motivate in-group cooperation, thus facilitating a wide range of cooperative behaviours including—but not limited to—peaceful resistance and collective aggression. However, little work has focused on whether violent conflict, in turn, might fuel greater religious participation. Here, we analyse survey data from 1,709 individuals in three post-conflict societies—Uganda, Sierra Leone and Tajikistan. The nature of these conflicts allows us to infer, and statistically verify, that individuals were quasirandomly afflicted with different intensities of war experience—thus potentially providing a natural experiment. We then show that those with greater exposure to these wars were more likely to participate in Christian or Muslim religious groups and rituals, even several years after the conflict. The results are robust to a wide range of control variables and statistical checks and hold even when we compare only individuals from the same communities, ethnic groups and religions.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Individuals more exposed to war are more likely to be members of religious groups years after the end of local conflicts.

Code availability

All code files for a complete reproduction of the analyses herein are available at:

Data availability

All data and analytical scripts are available at:


  1. 1.

    Purzycki, B. G. & Gibson, K. Religion and violence. Skeptic 16, 22–27 (2011).

    Google Scholar 

  2. 2.

    Atran, S. The devoted actor: unconditional commitment and intractable conflict across cultures. Curr. Anthropol. 57, S192–S203 (2016).

    Article  Google Scholar 

  3. 3.

    Norenzayan, A. et al. The cultural evolution of prosocial religions. Behav. Brain Sci. (2016).

  4. 4.

    Purzycki, B. G. The minds of gods: a comparative study of supernatural agency. Cognition 129, 163–179 (2013).

    PubMed  Article  Google Scholar 

  5. 5.

    Ruffle, B. J. & Sosis, R. Does it pay to pray? Costly ritual and cooperation. B. E. J. Econom. Anal. Policy (2007).

  6. 6.

    Atran, S. Genesis of suicide terrorism. Science 299, 1534–1539 (2003).

    CAS  PubMed  Article  Google Scholar 

  7. 7.

    Ruffle, B. J. & Sosis, R. Cooperation and the in-group-out-group bias: a field test on Israeli kibbutz members and city residents. J. Econ. Behav. Organ. 60, 147–163 (2006).

    Article  Google Scholar 

  8. 8.

    Sosis, R., Kress, H. & Boster, J. Scars for war: evaluating signaling explanations for cross-cultural variance in ritual costs. Evol. Hum. Behav. 28, 234–247 (2007).

    Article  Google Scholar 

  9. 9.

    Sheikh, H., Ginges, J., Coman, A. & Atran, S. Religion, group threat and sacred values. Judgm. Decis. Mak. 7, 110–118 (2012).

    Google Scholar 

  10. 10.

    McKay, R., Efferson, C., Whitehouse, H. & Fehr, E. Wrath of God: religious primes and punishment. Proc. Biol. Sci. 278, 1858 (2011).

    PubMed  Article  Google Scholar 

  11. 11.

    McCullough, M. E. & Willoughby, B. L. B. Religion, self-regulation, and self-control: associations, explanations, and implications. Psychol. Bull. 135, 69–93 (2009).

    PubMed  Article  Google Scholar 

  12. 12.

    Blogowska, J., Lambert, C. & Saroglou, V. Religious prosociality and aggression: it’s real. J. Sci. Study Relig. 52, 524–536 (2013).

    Article  Google Scholar 

  13. 13.

    McKay, R. & Whitehouse, H. Religion and morality. Psychol. Bull. 141, 447–473 (2015).

    PubMed  Article  Google Scholar 

  14. 14.

    Bushman, B. J., Ridge, R. D., Das, E., Key, C. W. & Busath, G. L. When God sanctions killing—effect of scriptural violence on aggression. Psychol. Sci. 18, 204–207 (2007).

    PubMed  Article  Google Scholar 

  15. 15.

    Clingingsmith, D., Khwaja, A. I. & Kremer, M. Estimating the impact of the Hajj: religion and tolerance in Islam’s global gathering. Q. J. Econ. 124, 1133–1170 (2009).

    Article  Google Scholar 

  16. 16.

    Rothschild, Z. K., Abdollahi, A. & Pyszczynski, T. Does peace have a prayer? The effect of mortality salience, compassionate values, and religious fundamentalism on hostility toward out-groups. J. Exp. Soc. Psychol. 45, 816–827 (2009).

    Article  Google Scholar 

  17. 17.

    Shen, M. J., Yelderman, L. A., Haggard, M. C. & Rowatt, W. C. Disentangling the belief in God and cognitive rigidity/flexibility components of religiosity to predict racial and value-violating prejudice: a post-critical belief scale analysis. Pers. Individ. Differ. 54, 389–395 (2013).

    Article  Google Scholar 

  18. 18.

    Wansink, B. & Wansink, C. S. Are there atheists in foxholes? Combat intensity and religious behavior. J. Rel. Health 52, 768–779 (2013).

    Article  Google Scholar 

  19. 19.

    Boyd, R. & Richerson, P. J. The Origin and Evolution of Cultures (Oxford Univ. Press, Oxford, 2005).

  20. 20.

    Boyd, R. & Richerson, P. J. Culture and the Evolutionary Process (Univ. of Chicago Press, Chicago, 1985).

  21. 21.

    Henrich, J. & Boyd, R. Why people punish defectors: weak conformist transmission can stabilize costly enforcement of norms in cooperative dilemmas. J. Theor. Biol. 208, 79–89 (2001).

    CAS  PubMed  Article  Google Scholar 

  22. 22.

    Roos, P., Gelfand, M., Nau, D. & Lun, J. Societal threat and cultural variation in the strength of social norms: an evolutionary basis. Organ. Behav. Hum. Decis. Process. 129, 14–23 (2015).

    Article  Google Scholar 

  23. 23.

    Henrich, J. The Secret of our Success: How Culture is Driving Human Evolution, Domesticating our Species, and Making us Smart (Princeton Univ. Press, Princeton, 2016).

  24. 24.

    Whitehouse, H., McQuinn, B., Buhrmester, M. & Swann, W. B. Brothers in arms: Libyan revolutionaries bond like family. Proc. Natl Acad. Sci. USA 111, 17783–17785 (2014).

    CAS  PubMed  Article  Google Scholar 

  25. 25.

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

    CAS  PubMed  Article  Google Scholar 

  26. 26.

    Harrington, J. R. & Gelfand, M. J. Tightness–looseness across the 50 united states. Proc. Natl Acad. Sci. USA 111, 7990–7995 (2014).

    CAS  PubMed  Article  Google Scholar 

  27. 27.

    Bornstein, G. & Benyossef, M. Cooperation in intergroup and single-group social dilemmas. J. Exp. Soc. Psychol. 30, 52–67 (1994).

    Article  Google Scholar 

  28. 28.

    Bornstein, G. & Erev, I. The enhancing effect of intergroup competition on group-performance. Int. J. Confl. Manage. 5, 271–283 (1994).

    Article  Google Scholar 

  29. 29.

    Puurtinen, M. & Mappes, T. Between-group competition and human cooperation. Proc. Biol. Sci. 276, 355–360 (2009).

    PubMed  Article  Google Scholar 

  30. 30.

    Saaksvuori, L., Mappes, T. & Puurtinen, M. Costly punishment prevails in intergroup conflict. Proc. Biol. Sci. 278, 3428–3436 (2011).

    PubMed  PubMed Central  Article  Google Scholar 

  31. 31.

    Francois, P., Fujiwara, T. & van Ypersele, T. The origins of human pro-sociality: cultural group selection in the workplace and the laboratory. Sci. Adv. 4, eaat2201 (2018).

    PubMed  PubMed Central  Article  Google Scholar 

  32. 32.

    Grant, F. & Hogg, M. A. Self-uncertainty, social identity prominence and group identification. J. Exp. Soc. Psychol. 48, 538–542 (2012).

    Article  Google Scholar 

  33. 33.

    Hogg, M. A. & Adelman, J. Uncertainty–identity theory: extreme groups, radical behavior, and authoritarian leadership. J. Soc. Issues 69, 436–454 (2013).

    Article  Google Scholar 

  34. 34.

    Smith, J. R., Hogg, M. A., Martin, R. & Terry, D. J. Uncertainty and the influence of group norms in the attitude–behaviour relationship. Br. J. Soc. Psychol. 46, 769–792 (2007).

    PubMed  Article  Google Scholar 

  35. 35.

    Bauer, M. et al. Can war foster cooperation? J. Econ. Perspect. 30, 249–274 (2016).

    Article  Google Scholar 

  36. 36.

    Bauer, M., Cassar, A., Chytilova, J. & Henrich, J. War’s enduring effects on the development of egalitarian motivations and in-group biases. Psychol. Sci. 25, 47–57 (2014).

    PubMed  Article  Google Scholar 

  37. 37.

    Voors, M. J. et al. Violent conflict and behavior: a field experiment in Burundi. Am. Econ. Rev. 102, 941–964 (2012).

    Article  Google Scholar 

  38. 38.

    House, B. R. et al. Ontogeny of prosocial behavior across diverse societies. Proc. Natl Acad. Sci. USA 110, 14586–14591 (2013).

    CAS  PubMed  Article  Google Scholar 

  39. 39.

    Barber, B. K. Contrasting portraits of war: youths’ varied experiences with political violence in Bosnia and Palestine. Int. J. Behav. Dev. 32, 298–309 (2008).

    Article  Google Scholar 

  40. 40.

    Sosis, R. & Handwerker, W. P. Psalms and coping with uncertainty: religious Israeli women’s responses to the 2006 Lebanon war. Am. Anthropol. 113, 40–55 (2011).

    Article  Google Scholar 

  41. 41.

    Lang, M., Krátký, J., Shaver, J.H., Jerotijević, D. & Xygalatas, D. Effects of anxiety on spontaneous ritualized behavior. Curr. Biol. 25, 1892-1897.

  42. 42.

    Boyer, P. & Lienard, P. Precaution systems and ritualized behavior. Behav. Brain Sci. 29, 635–650 (2006).

    Google Scholar 

  43. 43.

    Pargament, K., Harold, B. W. S., Koenig, G. & Perez, L. Patterns of positive and negative religious coping with major life stressors. J. Sci. Study Relig. 37, 710–724 (1998).

    Article  Google Scholar 

  44. 44.

    McNamara, R. A., Norenzayan, A. & Henrich, J. Supernatural punishment, in-group biases, and material insecurity: experiments and ethnography from Yasawa, Fiji. Religion Brain Behav. 6, 34–55 (2016).

    Article  Google Scholar 

  45. 45.

    Purzycki, B. G. et al. Moralistic gods, supernatural punishment and the expansion of human sociality. Nature 530, 327–330 (2016).

    CAS  PubMed  Article  Google Scholar 

  46. 46.

    Greenberg, J., Pyszczynski, T. & Solomon, S. in Public Self and Private Self (ed Baumeister R. F.) 189–212 (Springer, Berlin, 1986).

  47. 47.

    Norris, P. & Inglehart, R. Sacred and Secular: Religion and Politics Worldwide 2nd edn (Cambridge Univ. Press, Cambridge, 2012).

  48. 48.

    Stark, R. The Rise of Christianity: How the Obscure, Marginal Jesus Movement became the Dominant Religious Force in the Western World in a Few Centuries (Harper Collins, New York, 1997).

  49. 49.

    Gneezy, A. & Fessler, D. M. T. Conflict, sticks and carrots: war increases prosocial punishments and rewards. Proc. Biol. Sci. 279, 219–223 (2011).

    PubMed  PubMed Central  Article  Google Scholar 

  50. 50.

    Allen, T. & Vlassenroot, K. The Lord’s Resistance Army: Myth and Reality (Zed Books, London, 2010).

  51. 51.

    Bellows, J. & Miguel, E. War and local collective action in Sierra Leone. J. Public Econ. 93, 1144–1157 (2009).

    Article  Google Scholar 

  52. 52.

    HRW World Report 1999. Sierra Leone: Defending Human Rights. Human Rights Watch (1999).

  53. 53.

    Cassar, A., Grosjean, P. & Whitt, S. Legacies of violence: trust and market development. J. Econ. Growth 18, 285–318 (2013).

    Article  Google Scholar 

  54. 54.

    Bauer, M., Fiala, N. & Levely, I. V. Trusting former rebels: an experimental approach to understanding reintegration after civil war. Econ. J. 128, 1786–1819 (2018).

    Article  Google Scholar 

  55. 55.

    Altonji, J. G., Elder, T. E. & Taber, C. R. Selection on observed and unobserved variables: assessing the effectiveness of Catholic schools. J. Polit. Econ. 113, 151–184 (2005).

    Article  Google Scholar 

  56. 56.

    Turchin, P. Ultra Society: How 10,000 Years of War Made Humans the Greatest Cooperators on Earth (Beresta Books, Chaplin, CT, USA, 2015).

  57. 57.

    Willard, A. K., Henrich, J. & Norenzayan, A. Memory and belief in the transmission of counterintuitive content. Hum. Nat. 27, 221–243 (2016).

    PubMed  Article  Google Scholar 

  58. 58.

    Lanman, J. A. The importance of religious displays for belief acquisition and secularization. J. Contemp. Religion 27, 49–65 (2012).

    Article  Google Scholar 

  59. 59.

    Willard, A. K. & Cingl, L. Testing theories of secularization and religious belief in the Czech Republic and Slovakia. Evol. Hum. Behav. 38, 604–615 (2017).

    Article  Google Scholar 

  60. 60.

    Lanman, J. A. & Buhrmester, M. D. Religious actions speak louder than words: exposure to credibility-enhancing displays predicts theism. Religion Brain Behav. 7, 3–16 (2017).

    Article  Google Scholar 

  61. 61.

    McCleary, R. M. & Barro, R. J. Religion and economy. J. Econ. Perspect. 20, 49–72 (2006).

    Article  Google Scholar 

  62. 62.

    Atran, S. & Henrich, J. The evolution of religion: how cognitive by-products, adaptive learning heuristics, ritual displays, and group competition generate deep commitments to prosocial religions. Biol. Theory 5, 18–30 (2010).

    Article  Google Scholar 

  63. 63.

    Henrich, J. The evolution of costly displays, cooperation and religion: credibility enhancing displays and their implications for cultural evolution. Evol. Hum. Behav. 30, 244–260 (2009).

    Article  Google Scholar 

  64. 64.

    Cassar, A., Grosjean, P. & Whitt, S. in The economics of Conflict: Theory and Empirical Evidence (ed Warneryd K.) (MIT Press, Cambridge, MA, USA, 2013).

  65. 65.

    Rohner, D., Thoenig, M. & Zilibotti, F. Seeds of distrust: conflict in Uganda. J. Econ. Growth 18, 217–252 (2013).

    Article  Google Scholar 

  66. 66.

    Ginges, J., Hansen, I. & Norenzayan, A. Religious and popular support for suicide attacks. Psychol. Sci. 20, 224–230 (2009).

    PubMed  Article  Google Scholar 

  67. 67.

    Burger, J. M. & Lynn, A. L. Superstitious behavior among American and Japanese professional baseball players. Basic Appl. Soc. Psych. 27, 71–76 (2005).

    Article  Google Scholar 

  68. 68.

    Rudski, J. Competition, superstition and the illusion of control. Curr. Psychol. 20, 68–84 (2001).

    Article  Google Scholar 

  69. 69.

    Joukhador, J., Blaszczynski, A. & Maccallum, F. Superstitious beliefs in gambling among problem and non-problem gamblers: preliminary data. J. Gambl. Stud. 20, 171–180 (2004).

    PubMed  Article  Google Scholar 

  70. 70.

    Bleak, J. L. & Frederick, C. M. Supersititious behavior in sport: levels of effectiveness and determinants of use in three collegiate sports. J. Sport Behav. 2, 1–15 (1998).

    Google Scholar 

  71. 71.

    Legare, C. H. & Souza, A. L. Evaluating ritual efficacy: evidence from the supernatural. Cognition 124, 1–15 (2012).

    PubMed  Article  Google Scholar 

  72. 72.

    Legare, C. H. & Souza, A. L. Searching for control: priming randomness increases the evaluation of ritual efficacy. Cogn. Sci. 38, 152–161 (2014).

    PubMed  Article  Google Scholar 

  73. 73.

    Vail, K. E. et al. A terror management analysis of the psychological functions of religion. Pers. Soc. Psychol. Rev. 14, 84–94 (2010).

    PubMed  Article  Google Scholar 

  74. 74.

    Jonas, E. & Fischer, P. Terror management and religion: evidence that intrinsic religiousness mitigates worldview defense following mortality salience. J. Pers. Soc. Psychol. 91, 553–567 (2006).

    PubMed  Article  Google Scholar 

  75. 75.

    Pyszczynski, T., Sheldon, S. & Greenberg, J. In the Wake of 9/11: the Psychology of Terror (American Psychological Association, Washington DC, 2003).

  76. 76.

    Norenzayan, A., Atran, S., Faulkner, J. & Schaller, M. Memory and mystery: the cultural selection of minimally counterintuitive narratives. Cogn. Sci. 30, 531–553 (2006).

    PubMed  Article  Google Scholar 

  77. 77.

    Mikulincer, M. & Florian, V. Exploring individual differences in reactions to mortality salience: does attachment style regulate terror management mechanisms?. J. Pers. Soc. Psychol. 79, 260–273 (2000).

    CAS  PubMed  Article  Google Scholar 

  78. 78.

    Blattman, C. From violence to voting: war and political participation in Uganda. Am. Political Sci. Rev. 103, 231–247 (2009).

    Article  Google Scholar 

  79. 79.

    Atran, S., Sheikh, H. & Gomez, A. Devoted actors sacrifice for close comrades and sacred cause. Proc. Natl Acad. Sci. USA 111, 17702–17703 (2014).

    CAS  PubMed  Article  Google Scholar 

  80. 80.

    Atran, S. Combating Al Qaeda’s splinters: mishandling suicide terrorism. Wash. Q. 27, 67–90 (2004).

    Google Scholar 

  81. 81.

    Pape, R. A. The strategic logic of suicide terrorism. Am. Polit. Sci. Rev. 97, 343–361 (2003).

    Article  Google Scholar 

  82. 82.

    Dawkins, R. The God Delusion (Houghton Mifflin, Boston, 2006).

  83. 83.

    Harris, S. The End of Faith: Religion, Terror, and the Future of Reason (W. W. Norton, New York, 2005).

  84. 84.

    Hitchens, C. God is Not Great: How Religion Poisons Everything (Twelve, New York, 2007).

Download references


B.P. was supported by the Cultural Evolution of Religion Research Consortium which is funded by SSHRC and the John Templeton Foundation during the initial preparation of this manuscript. J.H. thanks CIFAR. M.B. and J.C. thank the Czech Science Foundation. A.C. acknowledges a grant from Title VIII/Department of State, Bureau of Intelligence and Research for fieldwork in Tajikistan and funding from the University of San Francisco for fieldwork in Sierra Leone. The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript.

Author information




M.B., J.C. and J.H. conceived the study and initiated manuscript preparation. M.B., A.C. and J.C. collected data (M.B. acknowledges N. Fiala and I. Levely as collaborators in the Ugandan project, A.C. acknowledges P. Grosjean and S. Whitt as collaborators in the Tajik project). M.B., J.C. and B.P. conducted analysis. M.B., A.C., J.C., J.H. and B.P. contributed to preparation of the manuscript, J.H. and B.P. had a lead role.

Corresponding author

Correspondence to Joseph Henrich.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Methods, Supplementary Discussion, and Supplementary Tables 1–19.

Reporting Summary

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Henrich, J., Bauer, M., Cassar, A. et al. War increases religiosity. Nat Hum Behav 3, 129–135 (2019).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing