Social DNA. M. Kay Martin

by promiscuous males, who are portrayed as naturally self-serving, devious, and irresponsible. Saddled as such with their “egg yokes,” females are equipped with few liberating tools beyond withholding sexual favors, clandestine entrapment of reluctant progenitors, or luck of the draw.

      Figure 1.1. Selfish-gene theory and the origin of female exploitation. By Drew Fagan.

      Dawkins’s selfish-gene hypothesis is taken to its logical extreme by van den Berghe (1979), who adopts it as a template for understanding the structure of human social groups, past and present. He proposes that coyness and slower erotic arousal have evolved as female strategies to counter male seduction and to ensnare men into monogamous or pair-bonded relationships. Males, in contrast, are naturally promiscuous, and seek to parasitize women for their reproductive potential. Male dominance, patrilineal descent groups, and polygyny are seen as natural outcomes of the desire of men to secure the reproductive power of women, assure paternity, increase the number of offspring, and maximize their inclusive fitness by passing property on to their sons. Matrilineal social groups, while recognized, are viewed as rare and aberrant, arising where paternity is made less certain by a high incidence of adultery, divorce, and the “cuckolding” of absentee males. In these situations, it is argued, parasitism by males is simply transferred to their brothers-in-law for the benefit of their uterine nephews, with whom they share genes through their sisters. According to van den Berghe (1979: 108): “In both types of society, women are dominated by men who set norms in an attempt to control women’s reproductive behavior for maximum male fitness.”

      The picture that emerges from such selfish-gene models, then, is that anisogamy has preprogrammed the sexes for asymmetrical and parasitic reproductive roles in the evolutionary drama. Males are typecast as the sexual protagonists and females as the reticent objects of their exploitation. Similar conclusions on the proclivities and copulatory appetites of the sexes were reached by Daly and Wilson (1978) and by Symons (1979).⁷

      Such theories generated immediate controversy and academic debate within the field of evolutionary biology. Is our species the product of a grand genomic zero-sum game? Were the selective pressures that favored cooperative behaviors and encephalization in evolving hominins exerted largely on males? Are female primates naturally passive, noncompetitive, and asexual? Continuing research over the ensuing decades has shed new light on these questions, and has challenged previous notions about both human sexuality and human societal origins.

      Complementarity and Cooperation

      An alternative perspective on the social consequences of anisogamy is that selective pressures favored the evolution of disparate but complementary behaviors among the sexes within the context of cooperative breeding communities. This theoretical framework assumes that both males and females are active players, each pursuing their reproductive strategies sexually, politically, and economically, and further, that their mutual reproductive success is enhanced by the creation of collaborative and overlapping alliances.

      By the mid 1970s, androcentric theories on human societal origins were being increasingly challenged by the women’s movement, and female scholars began to re-examine prevailing assumptions in the fields of anthropology and primatology.⁸ Sarah Hrdy, in her seminal work The Woman That Never Evolved (1981), questioned the notion that natural selection had exerted its influence primarily or exclusively on males. The book presented data that challenged existing stereotypes of primate behaviors, which had previously relied largely on observations of male dominance hierarchies and differential male access to estrus females. Women primatologists took to the field, placing primary research emphasis for the first time on the sexual and social lives of females. The results of these studies literally transformed our understanding of primate breeding systems (Small 1984, 1993).

      What researchers discovered is that female primates are far from the coy, asexual, demure, and parasitized creatures some portrayed them to be. Instead, they are often sexually aggressive, actively seeking the novelty and variety of multiple partners while utilizing sex to create strategic alliances that further their reproductive success. Females are also often highly competitive, commonly organizing themselves into stable hierarchies in which status and territories are passed from mother to daughter. These hierarchies may impact access to food resources and, because they have greater stability and permanence than male mating hierarchies, can play a critical role determining the overall social structure of the group. In short, female primates are deliberate and active participants in the game of reproductive success. The strategies of males and females are distinct but interdependent, and rely on an intricate web of same-sex and opposite-sex alliances. What these primate data suggest is that natural selection has exerted its pressures on the sexes from ancient times, both on individuals and on groups within the context of complex social networks that bind the members of a breeding community.

      The perception of anisogamy pursued in this book is consistent with this view. Just as the joining of the sperm and egg at conception requires a mutually active partnership, so the evolution of human society required the successful integration of male and female reproductive strategies. In the words of Christopher Ryan and Cacilda Jetha: “There’s no denying that men and women are different, but we’re hardly different species or from different planets or designed to torment one another. In fact, the interlocking nature of our differences testifies to our profound mutuality” (2010: 270).

      Models of why and how intersexual partnerships evolved need not be based on notions of conflict, parasitism, dominance, gender stereotypes, or zero-sum games. Rather, human advancement relied more on brains than brawn—that is, on the liberation of males and females from primitive limbic system responses and the corresponding ability to modify their behaviors and structure their alliances in ways that furthered their respective reproductive goals. The next chapter challenges prevailing theories on the nature of proto-human society and offers an alternative model of how ancient multimale-multifemale communities evolved on the basis of cooperative intra- and intersexual alliance.