Runaway Social Selection for Displays of Partner Value and Altruism



The discovery of evolutionary explanations for cooperation is one of the great achievements of late 20th century biology. As most readers know, benefits to the group rarely explain tendencies to help others (Williams, 1966; Dawkins, 1976), benefits to kin explain altruism in proportion to the coefficient of relatedness (Hamilton, 1964), and mutual benefits and reciprocal exchanges explain much cooperation between nonrelatives (Trivers, 1971). Subsequent theoretical and empirical studies have blossomed into a body of knowledge that can explain much social behavior (Wilson, 1975; Trivers, 1985; Dugatkin, 1997; Alcock, 2001; Hammerstein, 2003).



Thanks for very helpful comments from two anonymous reviewers, and to members of my laboratory group, and to colleagues who offered valuable advice along the way including Robert Axelrod, Lee Dugatkin, Steve Frank, Kern Reeve, Bobbi Low, Richard Nisbett, Peter Railton, Mary Rigdon, Stephen Salant, Stephen Stearns, Barbara Smuts, Mary Jane West-Eberhard, and to Lucy for inspiration.


  1. Alcock, J. (2001). The triumph of sociobiology. New York: Oxford University Press.Google Scholar
  2. Alexander, R. D. (1979). Darwinism and human affairs. Seattle, WA: University of Washington Press.Google Scholar
  3. Alexander, R. D. (1987). The biology of moral systems. New York: Aldine de Gruyter.Google Scholar
  4. Alexander, R. D. (2005) Evolutionary selection and the nature of humanity. In V. Hösle & C. Illies (Eds.), Darwinism and philosophy (pp. 301–348). Notre Dame: University of Notre Dame Press.Google Scholar
  5. Alexander, R. D., & Borgia, G. (1978). Group selection, altruism, and the levels of organization of life. Annual Review of Ecology and Systematics, 9, 449–474.Google Scholar
  6. Amundsen, T. (2000). Why are female birds ornamented? Trends in Ecology and Evolution, 15(4), 149–155.PubMedGoogle Scholar
  7. Ananth, M. (2005). Psychological altruism vs. biological altruism: Narrowing the gap with the Baldwin effect. Acta Biotheoretica, 53(3), 217–239.PubMedGoogle Scholar
  8. Andersson, M. (1994). Sexual selection. Princeton, NJ: Princeton University Press.Google Scholar
  9. Armbruster, W. S., Antonsen, L, & Pélabonb, C. (2005). Phenotypic selection on Dalechampia blossoms: Honest signaling affects pollination success. Ecology, 86(12), 3323–3333.Google Scholar
  10. Axelrod, R. (1984). The evolution of cooperation. New York: Basic Books, Inc.Google Scholar
  11. Axelrod, R. (1986). An evolutionary approach to norms. American Political Science Review, 80, 1095–1111.Google Scholar
  12. Axelrod, R., Hammond, R. A., & Grafen, A. (2004). Altruism via kin-selection strategies that rely on arbitrary tags with which they coevolve. Evolution, 58(8), 1833–1838.PubMedGoogle Scholar
  13. Axelrod, R. M. (1997). The complexity of cooperation: Agent-based models of competition and collaboration. Princeton, NJ: Princeton University Press.Google Scholar
  14. Barclay, P., & Willer, R. (2007). Partner choice creates competitive altruism in humans. Proceedings of the Royal Society B: Biological, 274(1610), 749–753.Google Scholar
  15. Barkow, J. H. (1989). Darwin, sex, and status: Biological approaches to mind and culture. Toronto: University of Toronto Press.Google Scholar
  16. Batson, C. D. (1991). The altruism question: Toward a social psychological answer. Hillsdale, NJ: L. Erlbaum, Associates.Google Scholar
  17. Boyd, R., Gintis, H., Bowles, S., & Richerson, P. J. (2003). The evolution of altruistic punishment. Proceedings of the National Academy of Sciences United States of America, 100(6), 3531–3535.Google Scholar
  18. Boyd, R., & Richerson, P. J. (1985). Culture and the evolutionary process. Chicago: University of Chicago Press.Google Scholar
  19. Bradbury, J. W., & Vehrencamp, S. L. (1998). Principles of animal communication. Sunderland, MA: Sinauer Associates.Google Scholar
  20. Breden, F., & Wade, M. J. (1991). “Runaway” social evolution: Reinforcing selection for inbreeding and altruism. Journal of Theoretical Biology, 153(3), 323–337.PubMedGoogle Scholar
  21. Brown, S. L., & Brown, R. M. (2006). Selective investment theory: Recasting the functional significance of close relationships. Psychological Inquiry, 17(1), 1–29.Google Scholar
  22. Brown, S. L., Nesse, R. M., Vinokur, A. D., & Smith, D. M. (2003). Providing social support may be more beneficial than receiving it: Results from a prospective study of mortality. Psychological Science, 14(4), 320–327.PubMedGoogle Scholar
  23. Bull, J. J., & Rice, W. R. (1991). Distinguishing mechanisms for the evolution of co-operation. Journal of Theoretical Biology, 149(1), 63–74.PubMedGoogle Scholar
  24. Byrne, R. W., & Whiten, A. (1988). Machiavellian intelligence: Social expertise and the evolution of intellect in monkeys, apes, and humans. Oxford: Oxford University Press.Google Scholar
  25. Connor, R. C. (1995). Altruism among non-relatives: Alternatives to the ‘Prisoner’s Dilemma.’ Trends in Ecology and Evolution, 10(2), 84–86.PubMedGoogle Scholar
  26. Cosmides, L. (1989). The logic of social exchange: Has natural selection shaped how humans reason? Studies with the Wason selection task. Cognition, 31(3), 187–276.PubMedGoogle Scholar
  27. Crespi, B. J. (2004). Vicious circles: Positive feedback in major evolutionary and ecological transitions. Trends in Ecology and Evolution, 19(12), 627–633.PubMedGoogle Scholar
  28. Crook, J. H. (1972). Sexual selection, dimorphism, and social organization in the primates. In B. Campbell (Ed.), Sexual selection and the descent of man (pp. 231–281). Chicago: Aldine.Google Scholar
  29. Darwin, C. (1871). The descent of man and selection in relation to sex. London: John Murray.Google Scholar
  30. Dawkins, R. (1976). The selfish gene. Oxford: Oxford University Press.Google Scholar
  31. de Waal, F. B. M., Macedo, S., Ober, J., & Wright, R. (2006). Primates and philosophers: how morality evolved. Princeton, NJ: Princeton University Press.Google Scholar
  32. Dennett, D. (1995). Darwin’s dangerous idea. New York: Simon and Schuster.Google Scholar
  33. Diamond, J. (2002). Evolution, consequences and future of plant and animal domestication. Nature, 418(6898), 700–707.PubMedGoogle Scholar
  34. Dugatkin, L. A. (1997). Cooperation among animals: An evolutionary perspective. New York: Oxford University Press.Google Scholar
  35. Dugatkin, L. A. (2006). The altruism equation: Seven scientists search for the origins of goodness. Princeton: Princeton University Press.Google Scholar
  36. Dunbar, R. I. (1998). The social brain hypothesis. Evolutionary Anthropology, 6, 178–190.Google Scholar
  37. Dunbar, R. I. M. (1996). Grooming, gossip, and the evolution of language. Cambridge, MA: Harvard University Press.Google Scholar
  38. Dunbar, R. I. M., Knight, C., & Power, C. (1999). The evolution of culture: An interdisciplinary view. New Brunswick, NJ: Rutgers University Press.Google Scholar
  39. Fehr, E., & Fischbacher, U. (2003). The nature of human altruism. Nature, 425(6960), 785–791.PubMedGoogle Scholar
  40. Fehr, E., & Henrich, J. (2003). Is strong reciprocity a maladaptation? On the evolutionary foundations of human altruism. In P. Hammerstein (Ed.), Genetic and cultural evolution of cooperation (pp. 55–82). Cambridge, MA: MIT Press in Cooperation with Dahlem University Press.Google Scholar
  41. Fehr, E., & Rockenbach, B. (2004). Human altruism: Economic, neural, and evolutionary perspectives. Current Opinions in Neurobiology, 14(6), 784–790.Google Scholar
  42. Frank, R. H. (1985). Choosing the right pond: Human behavior and the quest for status. New York: Oxford University Press.Google Scholar
  43. Frank, R. H. (1988). Passions within reason: The strategic role of the emotions. New York: W.W. Norton.Google Scholar
  44. Frank, R. H. (1999). Luxury fever: Why money fails to satisfy in an era of excess. New York: Free Press.Google Scholar
  45. Frank, S. A. (1997). The Price equation, Fischer’s fundamental theorem, kin selection and causal analysis. Evolution, 51(6), 1712–1729.Google Scholar
  46. Frank, S. A. (1998). Foundations of social evolution. Princeton, NJ: Princeton University Press.Google Scholar
  47. Frank, S. A. (2006). Social selection. In C. W. Fox & J. B. Wolf (Eds.), Evolutionary genetics: Concepts and case studies (pp. 350–363). New York: Oxford University Press.Google Scholar
  48. Gibbard, A. (1990). Wise choices, apt feelings: A theory of normative judgment. Oxford: Oxford University Press.Google Scholar
  49. Gintis, H. (2000). Strong reciprocity and human sociality. Journal of Theoretical Biology, 206, 169–179.PubMedGoogle Scholar
  50. Gintis, H., Smith, E. A., & Bowles, S. (2001).  Cooperation and costly signaling. Journal of Theoretical Biology,. 119(1), 103–119.Google Scholar
  51. Grafen, A. (1984). Natural selection, kin selection, and group selection. In J. R. Krebs & N. B. Davies (Eds.), Behavioural ecology: An evolutionary approach (pp. 62–84). Sunderland, MA: Sinauer.Google Scholar
  52. Grafen, A. (1990). Biological signals as handicaps. Journal of Theoretical Biology, 144, 517–546.PubMedGoogle Scholar
  53. Hamilton, W. D. (1964). The genetical evolution of social behavior I, and II. Journal of Theoretical Biology, 7, 1–52.PubMedGoogle Scholar
  54. Hammerstein, P. (2001). Games and markets: Economic behavior in humans and other animals. In R. Noë, J. A. R. A. M. v., Hooff, & P. Hammerstein (Eds.), Economics in nature: Social dilemmas, mate choice and biological markets (pp. 1–22). Cambridge: Cambridge University Press.Google Scholar
  55. Hammerstein, P. (2003). Genetic and cultural evolution of cooperation. Cambridge, MA: MIT Press in Cooperation with Dahlem University Press.Google Scholar
  56. Hardy, C. L., & Van Vugt, M. (2006). Nice guys finish first: The competitive altruism hypothesis. Personality and Social Psychology Bulletin, 32(10), 1402–1413.PubMedGoogle Scholar
  57. Henrich, J., & Boyd, R. (2001). Why people punish defectors. Weak conformist transmission can stabilize costly enforcement of norms in cooperative dilemmas. Journal of Theoretical Biology, 208(1), 79–89.PubMedGoogle Scholar
  58. Henrich, J., Boyd, R., Bowles, S., Camerer, C., Fehr, E., Gintis, H., et al. (2005). “Economic man” in cross-cultural perspective: Behavioral experiments in 15 small-scale societies. Behavioral and Brain Sciences, 28(6), 795–815.PubMedGoogle Scholar
  59. Henrich, J., McElreath, R., Barr, A., Ensminger, J., Barrett, C., Bolyanatz, A., et al. (2006). Costly punishment across human societies. Science, 312 (5781), 1767–1770.PubMedGoogle Scholar
  60. Hirshleifer, J. (1999). There are many evolutionary pathways to cooperation. Journal of Bioeconomics, 1, 73–93.Google Scholar
  61. Humphrey, N. (1997). Varieties of altruism – and the common ground between them. Social Research, 64, 199–209.Google Scholar
  62. Humphrey, N. K. (1976). The social function of intellect. In P. G. Bateson & R. A. Hinde (Eds.), Growing points in ethology (pp. 303–318). London: Cambridge University Press.Google Scholar
  63. Kahil, E. L. (2004). What is altruism? Journal of Economic Psychology, 25, 97–123.Google Scholar
  64. Katz, L. (2000). Evolutionary origins of morality: Cross disciplinary perspectives. Devon: Imprint Academic.Google Scholar
  65. Kitcher, P. (1993). The evolution of human altruism. The Journal of Philosophy, 90(10), 497–516.Google Scholar
  66. Kokko, H., Brooks, R., Jennions, M. D., & Morley, J. (2003). The evolution of mate choice and mating biases. Proceedings of the Royal Society B: Biological, 270 (1515), 653–664.Google Scholar
  67. Kokko, H., Jennions, M. D., & Brooks, R. (2006). Unifying and testing models of sexual selection. Annual review of Ecology and Evolutionary Systematics, 37, 43–66.Google Scholar
  68. Krebs, D. L. (2000). The evolution of moral dispositions in the human species. Annals of the New York Academy of Sciences, 907, 132–148.PubMedGoogle Scholar
  69. Krebs, J., & Dawkins R (1984). Animal signals: Mind-reading and manipulation. In J. R. Krebs & N. B. Davies, (Eds.), Behavioral ecology: An evolutionary approach (pp. 380–402). Sunderland, MA: Sinauer.Google Scholar
  70. Kummel, M., & Salant, S. W. (2006). The economics of mutualisms: Optimal utilization of mycorrhizal mutualistic partners by plants. Ecology, 87 (4), 892–902.PubMedGoogle Scholar
  71. Laland, K. N., Odling-Smee, J., & Feldman, M. W. (2000). Niche construction, biological evolution, and cultural change. Behavioral and Brain Sciences, 23 (1), 131–146; discussion 146–175.PubMedGoogle Scholar
  72. Lande, R., & Arnold, S. J. (1983). The measurement of selection on correlated characters. Evolution, 37, 1210–1226.Google Scholar
  73. Lasch, C. (1979). The culture of narcissism: American life in an age of diminishing expectations. New York: Warner Books.Google Scholar
  74. Leach, H. M. (2003). Human domestication reconsidered. Current Anthropology, 44 (3), 349–368.Google Scholar
  75. Leary, M. R., & Baumeister, R. F. (2000). The nature and function of self–esteem: Sociometer theory. In M. P. Zanna, (Ed.), Advances in experimental social psychology (Vol. 32, pp. 2–51). San Diego, CA: Academic Press.Google Scholar
  76. Lehmann, L., & Keller, L. (2006). The evolution of cooperation and altruism – A general framework and a classification of models. Journal of Evolutionary Biology, 19 (5), 1365–1376.PubMedGoogle Scholar
  77. Manson, J. H., Navarrete, C. D., Silk, J. B., & Perry, S. (2004). Time-matched grooming in female primates: New analyses from two species. Animal Behavior, 67, 493–500.Google Scholar
  78. Mealey, L. (1995). Sociopathy. Behavioral and Brain Sciences, 18 (3), 523–599.Google Scholar
  79. Midgley, M. (1994). The ethical primate: Humans, freedom, and morality. New York: Routledge.Google Scholar
  80. Miller, G. (2007). Sexual selection for moral virtues. Quarterly Review of Biology, 82 (2), 97–126.PubMedGoogle Scholar
  81. Miller, G. F. (2000). The mating mind: How sexual choice shaped the evolution of human nature. New York: Doubleday.Google Scholar
  82. Mills, J., & Clark, M. S. (1994). Communal and exchange relationships: Controversies and research. In R. Erber & R. Gilmour (Eds.), Theoretical frameworks for personal relationships (pp. 29–42). Hillsdale, NJ: Lawrence Erlbaum.Google Scholar
  83. Nesse, R. (2004). Cliff-edged fitness functions and the persistence of schizophrenia (commentary). Behavioral and Brain Sciences, 27 (6), 862–863.Google Scholar
  84. Nesse, R. M. (1990). Evolutionary explanations of emotions. Human Nature, 1 (3), 261–289.Google Scholar
  85. Nesse, R. M. (2001). Evolution and the capacity for commitment. New York: Russell Sage Foundation.Google Scholar
  86. Nesse, R. M. (2006). Why so many people with selfish genes are pretty nice – except for their hatred of The Selfish Gene. In A. Grafen & M. Ridley (Eds.), Richard Dawkins (pp. 203–212). London: Oxford University Press.Google Scholar
  87. Noë, R. (2001). Biological markets: Partner choice as the driving force behind the evolution of mutualisms. In R. Noë, J. A. R. A. M. v. Hooff, & P. Hammerstein (Eds.), Economics in nature: Social dilemmas, mate choice and biological markets (pp. 93–118). New York: Cambridge University Press.Google Scholar
  88. Noë, R., & Hammerstein, P. (1994). Biological markets: Supply and demand determine the effect of partner choice in cooperation, mutualism and mating. Behavioral Ecology and Sociobiology, 35, 1–11.Google Scholar
  89. Noë, R., & Hammerstein, P. (1995). Biological markets. Trends in Ecology and Evolution, 10 (8), 336–339.PubMedGoogle Scholar
  90. Noë, R., Hooff, J. A. R. A. M. v., & Hammerstein, P. (2001). Economics in nature: Social dilemmas, mate choice and biological markets. New York: Cambridge University Press.Google Scholar
  91. Nowak, M. A. (2006). Five rules for the evolution of cooperation. Science, 314 (5805), 1560–1563.PubMedGoogle Scholar
  92. Nowak, M. A., & Sigmund, K. (1998). Evolution of indirect reciprocity by image scoring. Nature, 393, 573–577.PubMedGoogle Scholar
  93. Pepper, J. W. (2007). Simple models of assortment through environmental feedback. Artificial Life, 13 (1), 1–9.PubMedGoogle Scholar
  94. Pepper, J. W., & Smuts, B. B. (2002). A mechanism for the evolution of altruism among nonkin: Positive assortment through environmental feedback. The American Naturalist, 160, 205–213.PubMedGoogle Scholar
  95. Pilot, M. (2005). Altruism as advertisement – a model of the evolution of cooperation based on Zahavi’s handicap principle. Ethology, Ecology and Evolution, 17 (3), 217–231.Google Scholar
  96. Price, E. O. (1984). Behavioral aspects of animal domestication. Quarterly Review of Biology, 59(1), 1–32.Google Scholar
  97. Queller, D. C. (1992). A general model for kin selection. Evolution, 46(2), 376–380.Google Scholar
  98. Queller, D. C., Ponte, E., Bozzaro, S., & Strassmann, J. E. (2003). Single-gene greenbeard effects in the social amoeba Dictyostelium discoideum. Science, 299(5603), 105–106.PubMedGoogle Scholar
  99. Queller, D. C., & Strassmann, J. E. (1998). Kin selection and social insects. BioScience, 48(3), 165–175.Google Scholar
  100. Reeve, H. K., & Shen, S. F. (2006). A missing model in reproductive skew theory: the bordered tug-of-war. Proceedings of the National Academy of Sciences USA, 103(22), 8430–8434.Google Scholar
  101. Ridley, M. (1997). The origins of virtue: Human instincts and the evolution of cooperation. New York: Viking.Google Scholar
  102. Riolo, R. L., Cohen, M. D., & Axelrod, R. (2001). Evolution of cooperation without reciprocity. Nature, 414(6862), 441–443.PubMedGoogle Scholar
  103. Roberts, G. (1998). Competitive altruism: From reciprocity to the handicap principle. Proceedings of the Royal Society B: Biological, 265(1394), 427–431.Google Scholar
  104. Rothstein, S. I. (1980). Reciprocal altruism and kin selection are not clearly separable phenomena. Journal of Theoretical Biology, 87, 255–261.PubMedGoogle Scholar
  105. Roughgarden, J., Oishi, M., & Akcay, E. (2006). Reproductive social behavior: Cooperative games to replace sexual selection. Science, 311(5763), 965–969.PubMedGoogle Scholar
  106. Sachs, J. L., Mueller, U. G., Wilcox, T. P., & Bull, J. J. (2004). The evolution of cooperation. Quarterly Review of Biology, 79(2), 135–160.PubMedGoogle Scholar
  107. Schaller, M., & Crandall, C. S. (2003). The psychological foundations of culture. Mahwah, NJ: Lawrence Erlbaum.Google Scholar
  108. Segerstråle, U. C. O. (2000). Defenders of the truth: The battle for science in the sociobiology debate and beyond. New York: Oxford University Press.Google Scholar
  109. Sigmund, K. (1993). Games of life: Explorations in ecology, evolution, and behaviour. New York: Oxford University Press.Google Scholar
  110. Silk, J. B. (2003). Cooperation without counting: The puzzle of friendship. In Hammerstein, P. (Ed.), Genetic and cultural evolution of cooperation: Dahlem workshop report (Vol. 29, pp. 39–54). Cambridge, MA: MIT Press.Google Scholar
  111. Simms, E. L., & Taylor, D. L. (2002). Partner choice in nitrogen-fixation mutualisms of legumes and rhizobia1. Integrative and Comparative Biology, 42(2), 369–380.PubMedGoogle Scholar
  112. Simon, H. A. (1990). A mechanism for social selection and successful altruism. Science, 250, 1665–1668.PubMedGoogle Scholar
  113. Smith, A. (1976 [1759]). The theory of moral sentiments. Oxford: Clarendon Press.Google Scholar
  114. Smuts, B. B. (1985). Sex and friendship in baboons. New York: Aldine Publishing Company.Google Scholar
  115. Stevens, J. R., Cushman, F. A., & Hauser, M. D. (2005). Evolving the psychological mechanisms for cooperation. Annual Review of Ecology, Evolution, and Systematics, 36(1), 499–518.Google Scholar
  116. Tanaka, Y. (1996). Social selection and the evolution of animal signals. Evolution, 50, 512–523.Google Scholar
  117. Tibbetts, E. A. (2004). Complex social behaviour can select for variability in visual features: A case study in Polistes wasps. Proceedings of the Royal Society B: Biological, 271(1551), 1955–1960.Google Scholar
  118. Tomasello, M. (1999). The cultural origins of human cognition. Cambridge, MA: Harvard University Press.Google Scholar
  119. Tooby, J., & Cosmides, L. (1996). Friendship and the Banker’s paradox: Other pathways to the evolution of adaptations for altruism. In J. M. Smith, W. G. Runciman, & R. I. M. Dunbar (Eds.), Evolution of social behaviour patterns in primates and man (pp. 119–143). London: The British Academy: Oxford University Press.Google Scholar
  120. Trivers, R. (2000). The elements of a scientific theory of self-deception. Annals of the New York Academy of Sciences, 907(1), 114–131.PubMedGoogle Scholar
  121. Trivers, R. L. (1971). The evolution of reciprocal altruism. Quarterly Review of Biology, 46, 35–57.Google Scholar
  122. Trivers, R. L. (1985). Social evolution. Menlo Park, CA: Benjamin/Cummings.Google Scholar
  123. Veblen, T. (1899). The theory of the leisure class: An economic study in the evolution of institutions. New York: Macmillan.Google Scholar
  124. Weber, B. H., & Depew, D. J. (2003). Evolution and learning: The Baldwin effect reconsidered. Cambridge, MA: MIT Press.Google Scholar
  125. Wedekind, C., & Milinski, M. (2000). Cooperation through image scoring in humans. Science, 288(5467), 850–852.PubMedGoogle Scholar
  126. West-Eberhard, M. J. (1975). The evolution of social behavior by kin selection. Quarterly Review of Biology, 50(1), 1–33.Google Scholar
  127. West-Eberhard, M. J. (1979). Sexual selection, social competition, and evolution Proceedings of the American Philosophical Society, 123(4), 222–234.Google Scholar
  128. West-Eberhard, M. J. (1983). Sexual selection, social competition, and speciation. Quarterly Review of Biology, 58(2), 155–183.Google Scholar
  129. West-Eberhard, M. J. (2003). Developmental plasticity and evolution. New York: Oxford University Press.Google Scholar
  130. West, S. A., Griffin, A. S., & Gardner, A. (2007). Social semantics: Altruism, cooperation, mutualism, strong reciprocity and group selection. Journal of Evolutionary Biology, 20(2), 415–432.PubMedGoogle Scholar
  131. West, S. A., Pen, I., & Griffin, A. S. (2002). Cooperation and competition between relatives. Science, 296(5565), 72–75.PubMedGoogle Scholar
  132. Wilkinson, G. S. (1984). Reciprocal food sharing in the vampire bat. Nature, 308, 181–184.Google Scholar
  133. Williams, G. C. (1966). Adaptation and natural selection: A Critique of some current evolutionary thought. Princeton, NJ: Princeton University Press.Google Scholar
  134. Wilson, D. S., & Sober, E. (1994). Reintroducing group selection to the human behavioral sciences. Behavioral and Brain Sciences, 17(4), 585–607.Google Scholar
  135. Wilson, E. O. (1975). Sociobiology. Cambridge, MA: Harvard University Press.Google Scholar
  136. Wolf, J. B., Brodie, E. D. III, & Moore, A. J. (1999). Interacting phenotypes and the evolutionary process. II. Selection resulting from social interactions. American Naturalist, 153, 254–266.Google Scholar
  137. Wright, R. (1994). The moral animal: The new science of evolutionary psychology. New York: Pantheon Books.Google Scholar
  138. Wynne-Edwards, V. C. (1962). Animal dispersion in relation to social behavior. Edinburgh: Oliver and Boyd.Google Scholar
  139. Wu, J., & Axelrod, R. (1995). How to cope with noise in the iterated prisoner’s dilemma. Journal of conflict resolution, 39(1), 183–189.Google Scholar

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© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.The University of MichiganAnn ArborUSA

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