I am an anthropologist who began my career by doing an ethnography of the Yomut Turkmen of northern Iran in the 1960s and 1970s. This ethnography focused mainly on social organization. The Yomut community I lived with, much of the time from December 1965 to October 1967, was a pastoral group and, in addition to my ethnography, I did research leading to articles about their pastoral economy and its relationship to other aspects of their lives. Beyond describing the social life of the pastoral Yomut, I developed the hypothesis that, for the Yomut and probably many other pastoral groups in the Middle East, nomadism was a political and military strategy as well as an economic one. After my initial work on the pastoral Yomut, I then moved on to do a demographic study of the Yomut in 1973-74 which was designed to test the hypothesis that the Yomut regulate their population density by social means in the manner theorized by Wynne-Edwards and Carr-Saunders. The research disconfirmed this hypothesis. Form there I went on test other evolutionary hypotheses with my Yomut data most of which were confirmed. I also developed some ideas about how human behavior is shaped by our evolutionary past. These include the cultural-and-reproductive-success hypothesis, the concept of adaptively relevant environments, and the theory that religion functions as a commitment device and that the psychological underpinnings of religion are evolved adaptations which help people to from and maintain cohesive groups. (My idea about religion is and expansion of Thomas Schelling’s idea about commitment and hard-to-fake signals of commitment.) These ideas are described on the page labeled “ideas” and in articles included on the “articles” page.


William Irons
Professor Emeritus
Department of Anthropology
Northwestern University
1810 Hinman Avenue
Evanston, IL 60208-1310

Email addresses:;



B. A., University of Michigan, 1960

Research Student, London School of Economics, 1964-1965

Ph.D., University of Michigan, 1969


Assistant Professor of Social Relations, The Johns Hopkins University (July 1, 1969 – June 30, 1974)

Assistant Professor of Anthropology, The Pennsylvania State University (September 1, 1974 – June 30, 1978)

Associate Professor of Anthropology, Northwestern University (September 1978 – August 1983)

Professor of Anthropology, Northwestern University (September 1983 – 2010)

Professor Emeritus of Anthropology, Northwestern University (2010 – present)


Phi Kappa Phi, University of Michigan, 1969

Fellow of the American Association for the Advancement of Science (elected 1980)

President of the Human Behavior and Evolution Society, June 2001 – June 2003.

President of the Evolutionary Anthropology Society (a new section of the American Anthrologocical Association), May 2004 ñ November 2005

Lifetime Achievement Award for the Study of Pastoral Nomads from the Commission on Nomadic Peoples (CNP), International Union of Anthropological
and Ethnological Sciences (IUAES), 2000. [For a description of the accomplishments justifying this award go]

Lifetime Career Award from the Human Behavior and Evolution Society ( in July 2011.


Developing theory concerning the evolutionary foundations of religion and morality; empirical evaluation of evolutionary hypotheses derived from evolutionary theory especially with data gathered among the Turkmen of northern Iran; refinement of theory in human behavioral ecology


Iran, 1965-1967: ethnography, social organization, and descriptive ecology of the Yomut Turkmen (16 months); library research on history of the Turkmen using various published and unpublished sources in Tehran (6 months) while waiting for research permission; ethnographic survey of Bakhtiari and Luristan (2 months)

Afghanistan, 1967: ethnographic survey of Nuristan and Hazarajat (2 months)

Iran, 1970: ecology of the Yomut Turkmen (2 months); (1 month additional in Tehran waiting for research permission)

Iran, 1973-1974 (12 months): survey to obtain social and demographic data for testing hypotheses concerning the behavioral ecology of the Yomut Turkmen; (3 months additional in Tehran waiting for research permission, consulting with Iranian scientists and arranging to ship material home after the field research was complete)

Venezuela, 1991 (1 month): pilot demographic study of the Ye’kwana.

Bay Islands of Honduras, 1993 (2 weeks): pilot project to determine the feasibility of future research on the island of Utila.

Bay Islands of Honduras, 1996 (2 months): research (with Lee Cronk and Shannon Steadman of Texas A&M University) on the cultural norms governing family relationships (the study focused on specific hypotheses about audience effects and Rashamon effects derived from evolutionary theory).


1965. “Livestock Raiding Among Pastoralists: An Adaptive Interpretation,” Papers of the Michigan Academy of Science, Arts, and Letters 50: 393-414.

1968. “The Turkmen Nomads,” Natural History 77: 44-51.

Reprinted in Man’s Many Ways: The Natural History Reader in
Anthropology, Richard A. Gould (ed.), 1973: 245-258.

Reprinted in Many Answers, Norman Alger (ed.), 1974: 147-154.

Reprinted in The Evolution of Human Adaptation, John J.
Poggie,Jr., Gretel H. Pelto, and Pertti J. Pelto (eds.),
1976: 176- 181.

Reprinted in Man’s Many Ways: The Natural History Reader in
Anthropology, Second Edition, Richard A. Gould (ed.),
1977: 166-172.

1969. “The Turkmen of Iran: A Brief Research Report,” Iranian Studies 11: 27-38.

1971. “Variation in Political Stratification Among the Yomut Turkmen,” Anthropological Quarterly 44: 143-156.

1972. “Variation in Economic Organization: A Comparison of the Pastoral Yomut and the Basseri,” in Perspectives on Nomadism. William Irons and Neville Dyson-Hudson (eds.), pp. 88-104, Volume XIII: International Studies in Sociology and Social Anthropology. Leiden: E.J. Brill.

1972. Perspectives on Nomadism, Volume XIII: International Studies in Sociology and Social Anthropology. Leiden: E. J. Brill (co-edited with N. Dyson-Hudson). 136 pages.

1974. “Nomadism as a Political Adaptation: The Case of the Yomut Turkmen,” American Ethnologist 1: 635-658. [Downoad PDF]

1974. “Social Regulations of Population Sizes: The Implications of Research Among the Turkmen of North Iran,” Mardumshinasi va Farhang-i-’Ammah-yi-Iran 1: 4-19.

Translated into Persian and published simultaneously as “Tanzim va Tajdid-i Jam’iyyat ‘az Rahha-yi ‘Ijtima’i va Natayij-i Tahqiq dar barah-yi Turkumanha-yi Shumal-i-Iran,” Mardumshinasi va Farhang-i-’Ammah-yi-Iran 1: 84-101 (1974).

1975. The Yomut Turkmen: A Study of Social Organization Among a Central Asian Turkic Speaking Population, Anthropological Paper Number 58, Museum of Anthropology, University of Michigan. 193 pages.

1976. “Turkmen,” Family of Man 7: 2536-2538.

1977. “Comment on Chapple’s Review of E. O. Wilson, Sociobiology: The New Synthesis,” American Anthropologist 79: 896-898.

1978. “The Turkmen,” in Muslim Peoples: A World Ethnographic Survey. Richard V. Weeks (ed.), pp. 427-433. Westport: Greenwood Press.

1979. Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. Scituate, Massachusetts: Duxbury Press (co-edited with N. A. Chagnon). 625 pages.

1979. “Political Stratification among Pastoral Nomads,” in Production Pastorale et Societe. Equip pour Anthropologie et Ecologie des Societe Pastorale, Maison des Sciences de l’Homme (eds.), pp. 361-374. New Rochelle: Cambridge University Press; and Paris: Maison des Sciences de l’Homme.

1979. “Some Statements of Theory,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 1-4.

1979. “Natural Selection, Adaptation, and Human Social Behavior,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 4-38. Duxbury.

1979. “Kinship Strategies,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 84-90.

1979. “Investment and Primary Social Dyads,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 123-159. Duxbury.

1979. “Individual and Group Strategies,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 280-284.

1979. “Cultural and Biological Success,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 284-302. Duxbury. [Download PDF]

Reprinted in Human Nature: A Critical Reader, L. Betzig (ed.), 1996: pp. 36 – 49. New York: Oxford University Press.

1979. “Male and Female Strategies,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 401-405.

1979. “Retrospect and Prospect: Some Viewpoints,” in Evolutionary Biology and Human Social Behavior: An Anthropological Perspective. N. A. Chagnon and W. Irons (eds.), pp. 518-521.

1980. “Is Yomut Social Behavior Adaptive?” in Sociobiology: Beyond Nature/Nurture? George W. Barlow and James Silverberg (eds.), pp. 417-473. American Association for the Advancement of Science Series on Science: The State of the Art. Boulder, Colorado: Westview Press. [Download PDF]

1980. “The Place of Carpet Weaving in Turkmen Society,” in Turkmen: Tribal Carpets and Traditions. Louise W. Mackie and Jon Thompson (eds.), pp. 23-29. Washington, DC: The Textile Museum.

1980. “On Magnarella’s Review of ‘The Yomut Turkmen,’” American Anthropologist 82: 388-389.

1981. “Why Lineage Exogamy?” in Natural Selection and Social Behavior: Recent Research and New Theory. R. D. Alexander and D. W. Tinkle (eds.), pp. 476-489. New York: Chiron Press. [Download PDF]

1981. “Sociobiology and Levels of Explanation,” American Anthropologist 83: 147-149.

1982. “Comment on Williams’ Review of Evolutionary Biology and Human Social Behavior: An Anthropological Perspective,” American Anthropologist 84: 896-897 (co-authored with N. A. Chagnon).

1983. “Human Female Reproductive Strategies,” in Social Behavior of Female Vertebrates, Samuel K. Wasser (ed.), pp. 169-213. New York: Academic Press.

1986. “Yomut Family Organization and Inclusive Fitness,” in Proceedings of the International Meetings on “Variability and Behavioral Evolution,” pp. 227-236. Rome: Accademia Nazionale dei Linei.

1988. “Parental Behavior in Humans,” in Human Reproductive Behavior: A Darwinian Perspective. L. Betzig, M. Borgerhoff Mulder, and P. Turke (eds.), pp. 307-314. Cambridge University Press.

1990. “Where Did Morality Come From?” Loccomer Protokolle 78: 6-34.

1990. “Let’s Make Our Perspective Broader Rather Than Narrower: A Comment on Turke’s ‘Which Humans Behave Adaptively and Why Does It Matter?’,” Ethology and Sociobiology 11: 361-374.

1990. “Production and Use of Textiles by the Turkmen,” in Vanishing Jewels: Central Asian Tribal Weavings. Betty Prisch and George O’Bannon (eds.), pp. 45-58. Rochester, NY: Rochester Museum and Science Center.

1991. “How Did Morality Evolve?” Zygon: Journal of Religion and Science 26: 49-89. Download PDF of part 1, pp. 49 – 68; Download PDF of part 2, pp. 69 – 89]

1991. “Anthropology” in The Sociobiological Imagination, Mary Maxwell (ed.), pp. 71-90.

1994 “Why Are the Yomut Not More Stratified?” In Pastoralists at the Periphery: Herders in a Capitalist World, eds. Claudia Chang and Harold A. Koster, pp. 275-296. Tucson: The University of Arizona Press.

1996 “The Significance of Evolutionary Biology for Research on Human Altruism,” Loccomer Protokolle 92: 77 – 92.

1996. “Morality as an Evolved Adaptation” in Investigating the Biological Foundations of Human Morality, (ed.) James P. Hurd, pp. 5 – 32. Lewiston, NY: Edwin Mellen Press.

1996. “Morality, Religion and Human Evolution” in Religion and Science: History, Methods, Dialogue, (eds.) W. Mark Richardson and Wesley J. Wildman, pp. 375 – 399. New York: Routledge, Inc. [Download PDF of longer version of this paper]

1996. “Reflections on the Dialogue” in Religion and Science: History, Methods, Dialogue, (eds.) W. Mark Richardson and Wesley J. Wildman, pp. 425 – 426. New York: Routledge, Inc. (co-authored with Philip Hefner.)

1996. “Looking Back Two Decades” in Evolution and Human Behavior: A Critical Reader, (ed.) Laura L. Betzig, pp. 46 – 49. New York: Oxford University Press.

1996. “In Our Own Self Image: The Evolution of Morality, Deception, and Religion.” Skeptic 4(2): 50 – 61. [Download PDF of longer version of this paper]

1998. “Adaptively Relevant Environments Versus the Environment of Evolutionary Adaptedness.” Evolutionary Anthropology 6(6): 194 – 204. [Download PDF]

2000. “Why Do the Yomut Raise More Sons than Daughters,” in L. Cronk, N. A. Chagnon and W. Irons, (eds.) Adaptation and Human Behavior, pp. 223- 236. Hawthorn NY: Aldine De Gruyter.

2000. “Twenty Years for a New Paradigm” in L. Cronk, N. A. Chagnon and W. Irons, (eds.) Adaptation and Human Behavior, pp. 3 – 26. Hawthorn NY: Aldine De Gruyter.

2000. Adaptation and Human Behavior. Hawthorn NY: Aldine De Gruyter (Co-edited with L. Cronk, N. A. Chagnon). 512 pages.

2001. “Why Are Humans Religious? An Inquiry into the Evolutionary Origin of Religion.” Currents in Theology and Mission 28:3-4 (June/August 2001): 357 – 368.

2001. “Religion as a Hard-to-Fake Sign of Commitment.” in Evolution and the Capacity for Commitment. R. M. Nesse (ed.), pp. 292 – 309. New York: Russell Sage Foundation.

2002 “Yomut Family Organization and Demography” in The Biological Anthropology of Pastoral Nomads, eds. W. Leonard and M. Crawford, pp. 251 – 279.

2002. Article entitled “Human Sociobiology,” Encyclopedia of Evolution, Vol. 1, pp. 537 ñ 541. Oxford: Oxford University, 2002.

2003 “Cultural Capital, Livestock Raiding, and the Military Advantage of Traditional Pastoralists.” In Nomadic Pathways in Social Evolution. Nikolay N. Kradin, Dmitri M. Bondarenko, and Thomas J. Barfield (eds.) Pp. 63-72. Moscow: The Russian Academy of Sciences.

2004. “Napoleon A. Chagnon.” Short biography in Biographical Dictionary of Social and Cultural Anthropology, Vered Amit (ed.), pp. 88 – 89. London snd New York: Routledge.

2004. “An Evolutionary Critique of the Created Co-Creator Concept.” Zygon: Journal of Religion and Science 39(4): 773-790.

2005. “How Has Evolution Shaped Human Behavior? Richard Alexander’s Contribution to an Important Question.” Evolution and Human Behavior 26: 1 ñ 9.

2008. “Why People Believe (What Some Other People See As) Crazy Ideas” pp. 51 – 57, in The Evolution of Religion: Studies, Theories, and Critiques, Joseph Bulbulia, Richard Sosis, Erica Harris, Russell Genet, Cheryl Genet, and Karen Wyman (eds.), Collins Foundation Press. 2008.

2008. Torkomanha-ye Yomut: Motaleíat- e Sazman-e Ejtemai-ye yek Jamíiat-e Torkzaban dar Asia-ye Markazi. Translator Mohammad Amin Kaníani. Tehran: Nashreafkar, 1387 (2008) (This is a translation of my 1975 monograph above into Persian.)

2009. “The Intertwined Roles of Genes and Culture in Human Evolution.” Zygon: Journal of Religion and Science 44(2): 347 – 354.

2009. Monique Borgerhoff Mulder, Samuel Bowles, Tom Hertz, Adrian Bell, Jan Beise, Greg Clark, Ila Fazzio, Michael Gurven, Kim Hill, Paul L. Hooper, William Irons, Hillard Kaplan, Donna Leonetti, Bobbi Low, Frank Marlowe, Richard McElreath, Suresh Naidu, David Nolin, Patrizio Piraino, Rob Quinlan, Eric Schniter, Rebecca Sear,, Mary Shenk, Eric Alden Smith, Christopher von Rueden, Polly Wiessner, “Intergenerational Wealth Transmission and the Dynamics of Inequality in Small-Scale Societies” Science 326, 682. (Irons is 12th author)

2009. Lee Cronk, Drew Gerkey and William Irons, “Social Relationships Interviews as Experiments: Using Audience Effects to Examine,” Field Methods 2009; 21; 331 – 346.


1970. Review of City and Village in Iran: Settlement and Economy in the Kirman Basin, Paul Ward English. Madison: University of Wisconsin Press, 1966. Iranian Studies 3: 115-125.

1978. Comment on J. H. Barkow,”Social Norms, the Self and Sociobiology: Building on the Ideas of A. I. Hallowell,” Current Anthropology 19: 106-107.

1979. Review of Nomaden von Gharjistan: Aspekte der wirtschaftlichen, soczialen und politischen Organisation nomadischer Durrani-Paschtunen in Nordwestafghanistan, by Bernt Glatzer. Beitrage zur Sudasienforschung, 22, Weisbaden: Franz Steiner Verlag, 1977. American Anthropologist 81: 418-419.

1980. Review of Systematische Anthropologie, by Wolfgang Rudolph and Peter Tschohl. Uni-Taschenbucher 639. Munich: Wilhelm Fink, 1977. American Anthropologist 82: 134-135.

1980. Review of Human Family Systems, by Pierre L. van den Berghe. New York: Elsevier, 1979. American Ethnologist 7: 799-800.

1981. Comment on R. Cohen, “Evolutionary Epistemology and Human Values,” Current Anthropology 22: 211-212.

1982. Review of Human Nature and History, by Kenneth Bock. New York: Columbia University Press, 1980. American Anthropologist 84: 926-927.

1983. “Shall We Drop the Genetic Leash?” Comment on P. L. van den Berghe, “Human Inbreeding Avoidance: Culture in Nature,” Behavioral and Brain Sciences 6: 108-109.

1984. “The Turkmen,” in Muslim Peoples II: A World Ethnographic Survey. Richard V. Weeks (ed.), pp. 804-810. Westport: Greenwood Press.

1986. Review of Human Evolution: A Philosophical Anthropology, by Mary Maxwell. New York: Columbia University Press, 1984. The Quarterly Review of Biology 61(1): 153-154.

1986. “Useful Data But Rethink the Theory,” Comment on D. R. Vining, “Social versus Reproductive Success: The Central Theoretical Problem of Human Sociobiology,” Behavioral and Brain Sciences 9: 197-198.

1986. Comment on D. Rindos, “The Evolution of the Capacity for Culture: Sociobiology, Structuralism and Cultural Selectionism,” Current Anthropology 27(4): 327.

1987. Review of Primate Sociobiology, by J. Patrick Gray. New Haven, CT: HRAF Press. American Anthropologist 89(2): 505-506.

1988. Comment on D. R. White, “Rethinking Polygyny: Co-Wives, Codes, and Cultural Systems,” Current Anthropology 29(4): 562.

1988. Review of The Sociobiology of Ethnocentrism: Evolutionary Dimensions of Xenophobia, Discrimination, Racism and Nationalism, eds. Vernon Reynolds, Vincent Falger, and Ian Vine. Athens: University of Georgia Press, 1986. American Anthropologist 90(4): 1027-1028.

1989. “Mating Preferences Surveys: Ethnographic Follow-Up Would Be A Good Next Step,” Comment on D. M. Buss, “Sex Differences In Human Mate Preferences: Evolutionary Hypotheses Tested In 37 Cultures,” Behavioral and Brain Sciences 12: 24.

1989. “Kommentare zu Christian Vogel” Loccumer Protokolle 78: 58.

1991. Review of The Biology of Moral Systems, by Richard Alexander. New York: Aldine de Gruyter, 1987. Zygon: Journal of Religion and Science 26(2): 324-328.

1991. Comment on J. H. Manson and R. W. Wrangham, “Intergroup Aggression in Chimpanzees and Humans,” Current Anthropology 32: 380.

1993 “Monogamy, Contraception, and the Cultural and Reproductive Success Hypothesis: Essays on Comparative Human Development, eds. J. W. Stigler, R. A. Shweder, and G. Herdt. NY: Cambridge University Press, 1990. Zygon: Journal of Religion and Science 28: 377-382.

1995. Current Anthropology 36: 594-5. Comment on “Bridewealth and Its Correlates” by Monique Borgerhoff Mulder. (Item B.5 in last years supplement.)

1996. “Adaptation” The Encyclopedia of Cultural Anthropology, vol. 1, pp. 1 – 4. American Reference Publishing Company Inc.

1999. Comment on “Is Inequality Universal?” by Philip Carl Salzman, Current Anthropology 40(1): 48 – 49.

2000. Review of Why Sex Matters by Bobbi Low, Princeton University Press. Evolution and Human Behavior 21 (5): 365-368.

2009 “Alexander, Richard D. (b. 1929)” In: Evolution: The First Four Billion Years. Eds. Michael Ruse and Joseph Travis. Cambridge, MA: The Belknap Press of Harvard University Press. Pp. 406 ñ 407.

Comments are closed.