A further parallel between chimpanzees and small scale human societies comes from analyses of

A further parallel between chimpanzees and small scale human societies comes from analyses of two extreme warring societies, the Waorani of New Zealand and the Yanomamo of Venezuela. Though violence accounts for between 40-55% of all deaths in these two groups, attackers appeared immune to injury, with no more than 5% dying in battle, and often no deaths at all. Chimpanzee attackers are likewise immune to injury, due in large part to the strategic use of imbalances of power. The parallels between chimpanzees and humans living in small scale societies supports the idea that similar pressures favored the capacity for coalitionary killing in both species. Does this mean that each of these species should always kill in this way, and thus, as argued by Ferguson, the archaeological record should be chock full of deaths by coalitionary attackers? To argue for this position is to misunderstand the nature of an adaptation, and the arguments put forth by Wrangham as well as the evolutionary psychologists Martin Daly, Margo Wilson, and David Buss. As I discussed earlier on in this chapter, adaptations are contingent upon particular environmental circumstances. What is adaptive today need not be tomorrow. This is why it is not only unsurprising to see variation in the frequency of coalitionary killing among chimpanzee sites, among humans living in small scale societies, and among modern day humans who sometimes kill their spouses, stepchildren, and rivals, but predicted by evolutionary theory. Adaptations are economically efficient solutions to particular social or ecological problems. If those problems or pressures change, the original adaptation may have no impact on survival or a negative impact. A hiatus in the archaeological record — assuming this is the last word — is interesting with respect to the conditions that might favor or select against coalitionary killing, but in no way undermines the logic of an evolutionary adaptation, one shared by chimpanzees and humans. The second camp arguing against the parallels between humans and chimpanzees is defended by the economist Samuel Bowles and his colleagues. Unlike the anthropologists, Bowles is entirely sympathetic to biology but sees fundamental differences in the pattern of human killing and warfare. To explain these differences he invokes two important attributes of human societies that have only weak parallels in other species: large scale cooperation with unrelated others from the same group, together with hatred, symbolic labeling, and the motivation to hurt all others outside the group. These two factors, what Bowles calls parechial altruism, may have paradoxically generated both greater levels of cooperation within groups and higher rates of warfare between groups. Those groups with the best cooperators acquired the greatest resources and experienced the fewest losses due to cheaters and other morally corrosive rogues. This power and inward-looking favoritism led to self-defensive emotions and behaviors, ultimately leading to lethal aggression toward those with different beliefs and values. Thus parochialism and altruism co-evolved, hand in hand, breeding prejudice as a result of group safety. This evolutionary handshake resulted in warfare and our unique capacity as killers. Bowles’ analysis is interesting and consistent with my explanation of how we evolved the Hauser Chapter 1. Nature’s secrets 43 HOUSE_OVERSIGHT_012789