The Moral Animal: Why We Are, the Way We Are: The New Science of Evolutionary Psychology (36 page)

Well, maybe so. But judging by the large number of essentially asocial species, natural selection doesn't seem to share Ardrey's
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concern for social order. It is perfectly willing to let organisms pursue inclusive fitness amid anarchy. Besides, if you start thinking carefully about this group-selectionist scenario, problems arise. Granted, when two tribes meet in combat, or compete for the same resource, the more hierarchical and cohesive may win. But how did it get hierarchical and cohesive in the first place? How would genes counseling submission, and thus lowering fitness, manage to gain a foothold amid the everyday competition among genes within the society? Wouldn't they tend to be banished from the gene pool before they had a chance to demonstrate their goodness for the group? These are the questions group selection theories — such as Darwin's theory of the moral sentiments — often face and often fail to surmount.

The most widely accepted Darwinian explanation for hierarchy is simple, straightforward, and nicely compatible with observed reality. It is only with this theory in hand — only after taking a clear look at human social status, uncolored by morality and politics — that we can get back to the moral and political questions. In exactly what senses is social inequality inherent in human nature? Is inequality indeed, as Darwin suggested, a prerequisite for economic or political advancement? Are some people "born to serve" and others "born to lead"?

Throw a bunch of hens together, and, after a time of turmoil, including much combat, things will settle down. Disputes (over food, say) will now be brief and decisive, as one hen simply pecks the other, bringing quick deferral. The deferrals form a pattern. There is a simple, linear hierarchy, and every hen knows its place. A pecks B with impunity, B pecks C, and so on. The Norwegian biologist Thorleif Schjelderup-Ebbe noticed this pattern in the 1920s and gave it the name "pecking order." (Schjelderup-Ebbe also observed, in a frenzy of politically loaded overextrapolation: "Despotism is the basic idea of the world, indissolubly bound up with all life and existence... . There is nothing that does not have a despot."
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No wonder anthropologists shied away from evolutionary accounts of social hierarchy for so long.)
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The order of the pecking is not arbitrary. B had a marked tendency to defeat C in early conflicts, and A tended to prevail over B. So it isn't, after all, such a great challenge to explain the emerging social hierarchy as merely the sum of individual self-interest. Each hen is deferring to hens that will probably win anyway, saving itself the costs of battle.

If you've spent much time with chickens, you may doubt their ability to process a thought as complex as "Chicken A will beat me anyway, so why bother to fight?" Your doubt is well placed. Pecking orders are yet another case where the "thinking" has been done by natural selection, and so needn't be done by the organism. The organism must be able to tell its neighbors apart, and to feel a healthy fear of the ones that have brutalized it, but it needn't grasp the logic behind the fear. Any genes endowing a chicken with this selective fear, reducing the time spent in futile and costly combat, should flourish.

Once such genes pervade the population, hierarchy is part of the social architecture. The society may look, indeed, as if designed by someone who valued order over liberty. But that doesn't mean it was. As George Williams put it in
Adaptation and Natural Selection
, "The dominance-subordination hierarchy shown by wolves and a wide variety of vertebrates and arthropods is not a functional organization. It is the statistical consequence of a compromise made by each individual in its competition for food, mates, and other resources. Each compromise is adaptive, but not the statistical summation."
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This isn't the only conceivable explanation of hierarchy that skirts the pitfalls of group selectionism. Another is based on John Maynard Smith's concept of an evolutionarily stable state — more specifically, on his "hawk-dove" analysis of a hypothetical bird species. Imagine dominance and submission as two genetically based strategies, the success of each depending on their relative frequency. Being a dominant (for example, walking around intimidating submissives into giving you half their food) is fine so long as there are lots of submissives around. But as the strategy spreads, it grows less fruitful: there are fewer and fewer submissives to exploit, and meanwhile
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dominants encounter one another more and more, engaging in costly combat. That's why the submissive strategy can thrive; a submissive animal must often surrender some of its food, but it avoids the fighting that takes an increasingly large toll on dominants. The population should in theory equilibrate, with a fixed ratio of dominants to submissives. And, as with all evolutionarily stable states (recall the blue-gill sunfish from chapter three), this equilibrium ratio is the point at which each strategy enjoys the same reproductive success.
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There are species that this explanation seems to fit. Among Harris sparrows, darker birds are aggressive and dominant, and lighter ones more passive and submissive. Maynard Smith has found indirect evidence that the two strategies are equally conducive to fitness — the hallmark of an evolutionarily stable state.
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But when we move to the human species — and, indeed, when we move to other hierarchical species — this explanation for social hierarchy encounters problems. Prominent among them is the number of findings — in the Ache, the Aka, many other human societies, and many other species — that low status brings low reproductive success.
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This is not the hallmark of an evolutionarily stable mix of strategies. It is the hallmark of low-status animals trying to make the best of a bad situation.

For decades, while many anthropologists have downplayed social hierarchy, psychologists and sociologists have studied its dynamics, watching the facility with which members of our species sort themselves out. Put a group of children together, and before long they fall into distinct grades. The ones at the top are best liked, most frequently imitated, and, when they try to wield influence, best obeyed.
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The rudiments of this tendency are seen among children only a year old.
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At first, status equals toughness — high-ranking children are the ones that don't back down — and indeed, for males, toughness matters well through adolescence. But as early as kindergarten, some children ascend the hierarchy via skill in cooperation.
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Other talents — intellectual, artistic — also carry weight, especially as we grow older.

Many scholars have studied these patterns without bringing a Darwinian slant to their work, but it's hard not to suspect an innate underpinning for such robotic patterns of learning. Besides, status
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hierarchies run in our family. They emerge with great clarity and complexity in our nearest relatives, the chimps and bonobos, and are found also, if in simpler form, in gorillas, our next closest kin, and in many other primates.
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If you took a zoologist from another planet, showed him our family tree, and pointed out that the three species nearest our limb were inherently hierarchical, he would probably guess that we are too. If you then told him that hierarchy is indeed found in every human society where people have looked closely for it, and among children too young to talk, he might well consider the case closed.

There is more evidence. Some of the ways people signify their status, and the status of others, seem to hold steady across cultures. Darwin himself, after widely questioning missionaries and other world travelers, concluded that "scorn, disdain, contempt, and disgust are expressed in many different ways, by movements of the features, and by various gestures; and that these are the same throughout the world." He also noted that "a proud man exhibits his sense of superiority over others by holding his head and body erect."
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A century later, studies would show that posture becomes straighter immediately after social triumph — as, say, when a student gets a high test score.
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And the ethologist Irenaiis Eibl-Eibesfeldt would find that children in diverse cultures, after losing a fight, lower their heads in self-abasement.
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These universals of expression have reflections within. People in all cultures feel pride upon social success, embarrassment, even shame, upon failure, and, at times, anxiety pending these outcomes.
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Nonhuman primates send some of the same status signals as people. Dominant male chimps — and dominant primates generally — strut proudly and expansively. And after two chimpanzees fight over status, the loser crouches abjectly. This sort of bowing is thereafter repeated to peacefully express submission.

Beneath the behavioral parallels between human and nonhuman primates lie biochemical parallels. In vervet monkey societies, dominant males have more of the neurotransmitter serotonin than do their subordinates. And one study found that in college fraternities, officers,
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on average, have more serotonin than do their less powerful fraternity brothers.
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This is a good opportunity to extinguish a once-flourishing misconception that, though in decline, has yet to die its richly deserved death. It is
not
the case that all behavior under "hormonal control," or some other "biological control," is "genetically determined." Yes, there is a correlation between serotonin (a hormone, like all neuro-transmitters) and social status. But no, that doesn't mean that a given person's social status was "in the genes," preordained at birth. If you check the serotonin levels of a fraternity president well before his political ascent, or of an alpha vervet monkey well before his, you may find them unexceptional.
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Serotonin level, though a "biological" thing, is largely a product of the social environment. It isn't nature's way of destining people at birth for leadership; it's nature's way of equipping them for leadership once they've gotten there (and, some evidence suggests, of encouraging them to make a bid for leadership at a politically opportune moment).
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You too can have a high serotonin level, if you can get elected president of a college fraternity.

Certainly genetic differences matter. Some people's genes dispose them to be unusually ambitious, or clever, or athletic, or artistic, or various other things — including unusually rich in serotonin. But these traits depend, for their flowering, on the environment (and sometimes on each other), and their eventual translation into status can rest heavily on chance. No one is born to lead, and no one is born to follow. And to the extent that some people are born with a leg up in the race (as they surely are), that birthright probably lies at least as much in cultural as in genetic advantage. In any event, there are good Darwinian reasons to believe that
everyone
is born with the capacity for high serotonin — with the equipment to function as a high-status primate given a social setting conducive to their ascent. The whole point of the human brain is behavioral flexibility, and it would be very unlike natural selection, given that flexibility, to deny anyone a chance at the genetic payoffs of high status, should the opportunity arise.

What does serotonin do? The effect of neurotransmitters is so subtle, and so dependent on chemical context, that simple generalizations are risky. But often, at least, serotonin seems to relax people,
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make them more gregarious, more socially assertive, much as a glass of wine does. In fact, one of alcohol's effects is to release serotonin. As a slight and useful oversimplification, you might say that serotonin raises self-esteem; it makes you behave in ways befitting an esteemed primate. Extremely low levels of serotonin can accompany not just low self-esteem, but severe depression, and may precede suicide. Antidepressants such as Prozac boost serotonin.
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So far this book has said little about neurotransmitters like serotonin, or about biochemistry in general. That is partly because the biochemical links among genes, brain, and behavior are largely unfathomed. It is also because the elegant logic of evolutionary analysis often lets us figure out the role of genes without worrying about the nuts and bolts of their influence. But, of course, there always are nuts and bolts. Whenever we talk about the influence of genes (or environment) on behavior, thought, or emotion, we are talking about a biochemical chain of influence.

As these chains become clearer, they can give form to inchoate data, and help graft the data onto a Darwinian framework. Psychologists found several decades ago that artificially lowering self-esteem (by giving false reports about scores on a personality test) made people more likely to cheat in a subsequent game of cards. A more recent study finds that people with lower serotonin levels are more likely to commit impulsive crimes.
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Maybe both of these findings, translated into evolutionary terms, are saying the same thing: that "cheating" is an adaptive response, triggered when people are shunted to the bottom of the heap and thus find it hard to get resources legitimately. Maybe there's some truth to that ostensibly simplistic refrain about inner-city crime — that it grows out of "low self-esteem," as poor children are reminded, via TV and movies, that they're nowhere near the top of the roost. Again we see how Darwinism, often caricatured as genetically determinist and right-wing, can mesh with the sort of environmental determinism favored on the left.

We also see another way to test group-selectionist theories. If the acceptance of low status had evolved mainly as an ingredient of group success, success that then trickles down and benefits even the lowly,
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you wouldn't expect low-status animals to spend their time subverting the group's order.
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