This is Part 2 of a series on prestige competition and its broader contemporary effects. For other parts, click below.
From Dominance Hierarchy to Prestige Hierarchy
Let us now leave behind our abstracted pseudo-hierarchical animal and focus on a particular evolutionary branch. By best current estimates, we split off from the ancestors of our closest living cousins, the chimpanzees and bonobos, about 7-8 million years ago. Because it’s widely supposed that our last common ancestor (LCA) occupied an ecological niche very similar to that presently occupied by chimps and bonobos, these species can offer us a window, if only a cloudy one, into our early hominin past.
Chimps and bonobos are forest-dwelling, semi-arboreal omnivorous frugivores who live in hierarchical fission-fusion groups. Much has been written about the differences between these species, particularly vis-à-vis the unusual matriarchal nature of bonobo groups and their use of sexual (including homosexual) contact, in lieu of the aggression common to chimpanzees, to resolve disputes and tensions. It’s unclear which among chimpanzees and bonobos make for a more promising model of our LCA (but see this article for an interesting new datum); fortunately, that uncertainty needn’t detain us here, for I only wish to focus on two behavioral features common between them: the capacity to form strategic coalitions and a male-philopatric dispersal pattern.
In the spontaneous hierarchies of the monitor lizards studied by Uyeda, et al., body size and aggressiveness count for a great deal with respect to one’s ability to successfully dominate others. In the hierarchies of chimpanzees and bonobos, on the other hand, the story is rather less straightforward.
Male chimps often require not just fighting ability but political savvy to increase or maintain their social positions. They regularly form coalitions with other males who support them during challenges and who expect support in return. Though each party to a coalition may benefit by entering into it, the power gained through coalitional aggression is not typically shared equally among the principals. If chimps B and C form a coalition to unseat A, the resident alpha, only one of B and C will become the new alpha. Consequently, such partnerships are often fragile and fleeting. If B takes over for A, C may well break off with B and form a new coalition with D (or even the newly deposed A) to wrest power from B. Some coalitions, however, are fairly stable, maintained by grooming, meat sharing, and other affiliative activities. Each male has to invest in the other in order to keep the coalition strong. Cooperation thus becomes key to attaining and defending political power.
Among bonobos, females tend to occupy the top positions in the hierarchy, but here again coalitions (commonly maintained via frequent sexual contact) are crucial. Female-female coalitions are much more common in this species than in chimpanzees. By contrast, male-male coalitions are rare, but a male may rise in rank (though not, so far as we’ve observed, to alpha status) by forming a coalition with his high-ranking mother.
The presence of coalitions in these two species and in more distantly related outgroups (e.g., gorillas and macaques) strongly suggests that our last common ancestor forged cooperative coalitions as well, or at least had the cognitive capacity to do so. Hereinafter, for convenience, I’ll speak of our inherited “coalitional psychology.” I don’t mean to imply by this term a single, well-circumscribed adaptation of the sort evolutionary psychologists might posit, but only a kluge-y suite of faculties and dispositions, many of which may have had largely independent and diachronic evolutionary histories, which are jointly conducive to the formation and maintenance of stable coalitions.
In many social species, individuals of one sex will disperse from their natal groups upon reaching reproductive age. This helps them avoid both fiercer competition for resources owing to increasing population density and the genetic Russian roulette of inbreeding. In Pan sp. (bonobos and chimpanzees), males tend to be philopatric and females alone disperse from the natal group. Because these species are believed to occupy a similar ecological niche as our LCA, and because the nearest cladistic outgroup, the gorillas, are also male-philopatric, it’s likely that this pattern was the norm among the earliest hominins as well.
But in extant hunter-gatherer societies dispersal is bisexual and non-obligate (Hill, et al., 2011), with males and females relocating in roughly equal percentages. Such a pattern is almost unthinkable in Pan given the strong, often lethal aggression males of one group exhibit toward males of other groups. Something major had to change. One possibility is that as we moved out of the equatorial African forests and onto the open savanna, food resources would have become more widely dispersed and therefore difficult to defend, resulting in increased intergroup toleration. While this ecological change likely played some pacifying role, it almost certainly wasn’t sufficient. Anyone who has observed humans or any other animal for an appreciable length of time ought to know that food is not the only resource for which males compete with each other.
In Primeval Kinship, anthropologist Bernard Chapais argues—persuasively, in my view—that the crucial facilitator of this bisexual dispersal pattern (what he calls “the exogamy configuration”) was the evolution of long-term pair-bonding. In Pan, males and females both mate promiscuously and offspring are typically cared for only by their mothers—those for whom the genetic relatedness of the offspring is certain. Over the course of human evolution, the mating system shifted toward monogamy and males began to invest considerably in their children. Standard adaptationist explanations for this shift tend to focus on our increasing brain size and the resultant life history and dietary changes this both mandated and enabled. The rough idea is that as our brains and heads got bigger, we had to be born earlier (the mechanics of bipedality placed fairly strict constraints on hip width) and consequently cared for longer. Bigger brains also needed more nutrients—in particular, protein—and so it became necessary for males to start provisioning infants and their mothers with hunted game. Thus was fatherhood born.
Chapais, however, prefers a more phylogenetic story, one based on patterns observed in other primates. On this account, monogamy did not follow directly on the heels of the mixed polygamy seen in Pan, but came about only after an intermediate period of polygyny, which, like monogamy, would have increased paternal certainty. The question of how, exactly, pair-bonding arose in our ancestors is an interesting and important one, but it’s not nearly as relevant to this essay as are the consequences such a development brought about. With paternal investment, Chapais argues, a daughter could form strong consanguineal bonds not just with her mother but with her father and his relatives as well. Longer periods of post-weaning care would have given her more opportunity to also bond with siblings—most importantly, brothers.
A female raised under such circumstance would thus have many more emotional ties to her natal group than would, say, a chimpanzee. She would thus have much greater incentive (not to mention opportunity) to maintain affiliative contact with her natal group post-dispersal. What’s crucial here is that this female now has males in both groups who are invested in her and her offspring, but for different, complementary reasons. Importantly, because the invested males in her natal group are her kin, there will be no sexual competition over her with males in her newer group. Because of their noncompetitive affiliation with her, males in these groups now have compelling reasons to tolerate each other. In Chapais’ words, these females provide “appeasing bridges” (pp. 220-222) between their natal and reproductive groups, and the greater the number females relocating between these groups, the greater the number of males in each group with incentive to tolerate males from the other group.
As intergroup tensions eased, males would have been able to start traveling between groups as well. But a male might still be less welcome by default than a newly reproductive female. He is still a sexual competitor for those females in his new group with whom he’s not closely related. The average male also brings a comparatively larger capacity for disruptive violence into any group he joins. He could be a thief, a killer, a bringer of disease. Though his female kin may plead a case for him, he will need to get in good with the resident males in order to really be accepted (even in the female-dominated bonobos, males act as the principal gatekeepers of group membership). To earn and maintain his keep, he’ll need to demonstrate an ability and willingness to contribute to his new group in meaningful ways. He might be expected to help other males in hunts, to share game meat, or to defend group members from predators and attacks by rival bands. His coalitional psychology would have likely have been a key pre-adaptation here, for what he’s basically required to do is enter into a large and stable coalition with everyone in his new group (or at least a sufficient majority).
Now, such a coalition demands considerable sacrifice, and it was consequently probably not until we ventured out of the forest and onto the savanna that such sacrifice would have been worth it. Food on the open savanna is much more widely distributed, and meat in particular comes in larger, faster, more dangerous packages, a fact that would have strongly incentivized cooperative hunting. The savanna also offers less water, greater exposure to the elements, and fewer places to hide or flee from predators. The surest safety would have been in numbers. Thus, despite the sacrifice required, the benefits of group living for a newly savanna-foraging primate would have been considerable, probably even indispensable.
In Pan coalitions we already see traditional dominance beginning to lose viability to other, savvier forms of political persuasion. Now, in our hypothetical proto-human population, we have the emergence of a proper prestige system, one in which acceptance and influence are accorded on the basis of one’s contributions to the welfare of one’s groupmates. Kevin Simler, in a post over on Melting Asphalt, nicely illuminates the distinction between dominance and prestige (don’t mind the Redpill-y intro and the uncomfortable allusions to Platonic forms; the essay is very much worth reading). I won’t rehash the entire post here, but the key difference is that while dominance is taken by force or threat from individuals who submit reluctantly, prestige is given by individuals who admire willingly. In our proto-human populations, hopeful immigrants sought prestige to gain acceptance and influence within useful groups, and resident group members sought—and promised prestige to—immigrants who could bring beneficial skills, knowledge, and virtues to the communal table. Would-be dominators, those who would try to monopolize the group for their own exclusive benefit, could at this point have been easily subdued or driven out by large intragroup coalitions, and the advent of stone weapons (the first great equalizer) would have made attempts at group control via force and threat even more unwise.
Now, to get the most out of a coalition, one needs not only a willingness to invest in one’s coalition partners but capacities to monitor and police their investments as well. To do this, one needs a well-developed sense of fairness, an ability to track costs and benefits not only to oneself but to others and to compare the resulting ratios. The shift to bisexual dispersal was not the crucible for the evolution of this ability, as it’s a key component of our coalitional psychology and already well developed in even non-hominoid primates, but the modern exogamy configuration did provide a novel, expansionary context for it. Among these proto-humans, fairness had to be insisted upon not just between two coalition partners or two unaffiliated individuals performing some common task but between each adult and every other adult in the group. Perhaps the most significant refinement we introduced to this sense of fairness was a reduced toleration for outcomes that unfairly benefit not just others, but ourselves—a testament, likely, to how heavily policed these outcomes would have been by everyone else in the group (consider the development of self-conscious emotions like guilt and shame in this context).
The alliance between resident and immigrant group members would thus require constant vigilance, and prestige would have served as a reliable indicator of the health of this alliance to all concerned parties. As suggested earlier, it’s possible that immigrant men would have faced greater scrutiny here; a woman of newly reproductive age would make a large default (reproductive) contribution to any group she joins (this is why female transfers are tolerated even by the highly territorial chimps). Men, however, would have to continually prove their value to the community—and herein perhaps lies an explanation for Vandello and Boson’s observation that “[c]ompared with womanhood, which is typically viewed as resulting from a natural, permanent, and biological developmental transition, manhood must be earned and maintained through publicly verifiable actions.” If this is right, it does not mean that women were exempted from prestige competition, but only that such competition may have historically tended toward different form. This question will be explored in greater depth in the final Part of this series.
But immigrant men would not have been wholly without bargaining power themselves. Unlike male chimps, who are largely stuck in their natal groups and must compete within them if they’re to have any hope of raising their status, if these early men felt they weren’t being justly compensated for their contributions to a group, they could pack up and head to a different band. We can imagine a sort of supergroup-level negotiation process whereby men self-select into the groups willing to accord them the most prestige. Happily, those groups will tend to be the ones that most have need of the particular skills or expertise those men have to offer, so this process ought to tend toward mutual beneficence.
We could imagine a sort of hierarchy system developing here in which prestige succeeded dominance as the principle means by which one could attain political power and allocate group resources to one’s benefit. It is possible that we passed through an early stage of prestige hierarchy (if we did, such an era might well be the closest humanity’s ever come to a true meritocracy). By the time we arrive at anatomically modern hunter-gatherers, however, hierarchy of any kind seems almost entirely absent. In the next section, we turn to a closer examination of this improbable political feat.