No Two Alike

by Judith Rich Harris

  Although rough-and-tumble play is seen less often during adolescence, it tends to be more serious: more prevalent in teenagers who also engage in real aggression and more likely to escalate. Its purpose is the same but now the stakes are higher. A researcher who studied the playground tussles of twelve- and thirteen-year-old boys reported, “Once a weaker boy has registered distress the [friendship] bond can be maintained by the fight taking a more playful form, but if he does not do so at the start of the fight, the stronger boy may increase the intensity of the fight until he does.”18

  Notice how the stronger boy lets up as soon as the weaker one cries uncle. When I said that this chapter is about classic Darwinian competition, the words “nature red in tooth and claw” may have popped into your head. But the sort of competition that is more apt to turn bloody is competition between groups, not within them. Within-group homicide does occur but it is not routine. Because the members of group-adapted species need their groupmates (and may be related to them), aggression within the group tends to be muted, tamped down. The members of most group-adapted species—no doubt our own included—have instincts that serve this purpose. The weaker individual demonstrates by its behavior that it accepts its lower status and the demonstration has a pacific effect on the stronger one. The subordinate wolf or dog rolls over and exposes its tender underbelly to the dominant one. Within the group—between two animals that know each other—this seemingly suicidal behavior averts, rather than invites, aggression.19 The goal of the stronger one is to dominate, not to kill.

  Ask a four-year-old boy who is the toughest or the smartest in his nursery school class and the answer you will probably get is “Me!”20 The status sociometer arrives from the factory with a default setting of alpha. Even after many years of use, it is still apt to register high. The tendency for people to overestimate themselves—in toughness, smartness, looks, honesty, niceness, driving ability, you name it—has been demonstrated again and again. The exceptions are people suffering from depression. But depressed people don’t actually underestimate themselves: they estimate themselves pretty accurately, which turns out not to be such a good idea.21

  It wouldn’t do, however, to run around with one’s sociometer forever fixed at the factory default. A 97-pound weakling who goes around trying to dominate everyone he meets is likely to lead a life that is nasty, brutish, and short. An individual has to learn that there are areas of endeavor in which he might be able to compete successfully and others in which it is best to cut his losses and concede defeat. Childhood is the time to find these things out: a time when a mistake is less likely to have irrevocable consequences.

  The very same four-year-old boy who told you that he is the toughest in his nursery school class tells a different story by his behavior: he averts his eyes and yields possession of toys when challenged by a bigger, stronger classmate. Dominant-submissive relationships are clearly visible in behavior at this age; and yet the child has little or no idea of his status in the group as a whole.22 Dominance and submission are the outcome of pairwise interactions between individuals and are handled by the relationship system, which (as I said in chapter 7) is ready to go from birth. A dominance hierarchy is the larger, group-wide structure that results from these interactions. Awareness of such structures and understanding of one’s own position in them requires a higher level of cognitive sophistication. The status system is the slowest of the three systems to develop.

  By kindergarten age—five or six—boys have a much better idea of their toughness relative to other boys, and by first grade they are fairly accurate (though still overly optimistic) in their self-assessment. They can also, by first grade, do a pretty good job of ranking their classmates in toughness. Ranking themselves and others in smartness takes a little longer, because the necessary information is harder to come by. But by second or third grade, they can do this too.23 I’m focusing here on toughness and aggressiveness because a lot of research has been done on these things and because they are obviously pertinent to Darwinian fitness, especially in males.

  Whether aggressiveness will be a successful behavioral strategy for a particular male depends in part on his genetic endowment, in part on environmental factors that his genes cannot foresee. An individual’s physical size and strength are affected, not only by genes, but also by things like malnutrition, parasites, illnesses, and injuries, which would have taken a heavier toll under ancestral conditions than they do today. Moreover, bigness and toughness are not absolutes: they depend on how you compare with the competition. The luck of the draw could give you Woody Allen or it could give you Shaquille O’Neal. A kid who ranks alpha in his play group might be beta, gamma, or omega in another group. Culture matters, too. Aggressiveness works better in some cultures than in others.

  In earlier chapters I described evidence showing that children’s experiences at home do not affect their aggressiveness outside the home. Firstborns who dominate their younger siblings are no more aggressive than laterborns when they’re with their peers. Kids who are well-behaved in the presence of their parents may be bullies on the playground. My conclusion was that children’s experiences at home have only short-term, context-specific effects on their behavior. Now the question is whether children’s experiences outside the home have long-term consequences. In order to convince you that the status system has the power I attribute to it, I need to provide evidence that children’s experiences with their peers (in this case, experiences related to aggressiveness and dominance) do in fact have long-term effects on personality.

  One way to do that would be to show that having high or low social status in childhood has effects on adult personality. Do the social experiences associated with being bigger, stronger, or more physically mature than others of his age have lasting effects on a boy’s personality? There is plenty of evidence for a connection between physical size or strength, status, and personality in adulthood (tall or muscular men tend to have higher status and to be more competitive and aggressive),24 but what I need now is a link between physical size or strength in childhood and personality in adulthood.

  That link is provided by longitudinal studies of height. The starting point is the well-established finding that tall men, on average, earn higher salaries than short men. The difference isn’t negligible: it amounts to around eight hundred dollars per inch in annual income.25 Though evolutionary psychologists are not surprised by this finding, economists find it puzzling. The salaried workers in question are not playing basketball; they’re not even changing lightbulbs. Mostly they’re just sitting behind a desk. Why would it be worth it to an employer to pay a higher salary to a tall guy if all he’s going to do is sit behind a desk?

  Recently three economists—Nicola Persico, Andrew Postlewaite, and Dan Silverman—attempted to answer that question. They were lucky enough to have access to two large databases of information on almost 4,500 white American and British males, including the subjects’ salary and height in adulthood (around age thirty), height at age sixteen, and, for about half of the subjects, height at ages seven and eleven. There was also a good deal of background information on the subjects.

  The economists analyzed the data till smoke started coming out of their computers, but they didn’t find the answer to the question of why tall guys get paid more. What they found instead was another puzzle. Employers, they discovered, are not paying for height per se—that is, they are not paying for adult height. What matters in terms of salary is not height in adulthood but height in adolescence. Though a man who is taller than average in adulthood is also likely to have been taller than average in adolescence, the rank ordering of individuals can change, and this enabled the economists to statistically separate the effects of height at different ages. They found that the men with the fattest paychecks were not necessarily those who were tallest at age thirty: they were those who had been tallest at age sixteen. As for height at ages seven and eleven, it made little difference once height at age sixteen was statistically controlled.26r />
  The economists tested several hypotheses that might explain what they called the “teen height premium.” Differences in childhood health didn’t account for it; nor was it a function of the socioeconomic status of the subjects’ parents. Of the factors they looked at, the one that mattered most—it accounted for about a third of the teen height premium—was participation in extracurricular activities in high school, especially participation in sports. Notice that participation in sports requires strength as well as size, and that high school athletes generally have high status among their peers.

  The economists’ conclusion was that employers aren’t paying a premium just to have tall employees. Employers are paying for something else—something associated with being tall in adolescence and with being good at sports, something that must persist into adulthood. What could it be?

  The answer, had the economists known where to look for it, was provided by a much older, much smaller study done—no, not by a social psychologist, but by a developmentalist. Her name was Mary Cover Jones and her research was published in 1957. As far as I know it has never been replicated—except, in an indirect way, by the three economists.

  Jones studied two types of subjects: teenage boys who were maturing slowly (in the bottom 20 percent for their age in terms of bone maturity) and teenage boys who were maturing rapidly (top 20 percent). These boys differed considerably in size; the gap was widest at age fourteen, when the early maturers averaged a whopping eight inches taller and thirty-four pounds heavier than the slow maturers.

  The marked differences in size, strength, and success in sports (which Jones mentioned in passing) were accompanied, in adolescence, by differences in personality and social behavior. In ratings by trained observers, the early maturers scored higher on “behavior items suggesting a large component of self-acceptance”: they were poised, relaxed, and matter-of-fact. In contrast, the slow maturers were eager, talkative, and tense, and more likely to have mannerisms that Jones described as “affected” and “attention-seeking.” Boys who are small for their age tend to be pushed around a lot by their peers; other researchers have found that such boys have more than their share of mental health disturbances.27

  The slow maturers eventually caught up in size; in their early thirties, when Jones revisited them, the two groups of subjects differed by an average of only half an inch. They were also about equal in educational attainment. But the early maturers were more likely to have achieved what Jones called “status-conferring” positions in their careers, and there were still significant differences in personality (as measured now by standard personality tests) between the groups: the early maturers scored higher on personality characteristics associated with dominance.28

  Jones’s study and the one by the three economists fit together like Lego blocks. Qualities such as tallness, strength, and athletic ability give a boy high status in his adolescent peer group,29 and having high status in adolescence has lasting effects on his personality. It makes him more sure of himself, more dominant, more competitive, more of a leader. These personality characteristics impress employers and they also impress voters. In presidential elections in the United States, the taller candidate usually wins.30

  The finding that height in adolescence matters more than height in childhood implies that personality can still be modified as late as age sixteen. This is consistent with the results of the study of personality development across the life course, which I mentioned in chapter 1, and suggests that the status system does its work at a more leisurely pace than the socialization system. Sixteen is not too late for a boy to develop a self-assured personality, but it is too late for the son of a Japanese executive who has lived for several years in the United States to return to Japanese norms of social behavior, and it is too late for a new immigrant to learn to speak the language of his new country without an accent.31 Each system has its own developmental timetable.

  Personality can change during childhood and adolescence as a result of experiences. Theorists who believe that children’s personalities are shaped early, presumably by experiences at home, have been misled by the continuities they see in personality: the timid child who becomes a timid adult, the conscientious child who becomes a conscientious adult. Such continuities are due mainly to genetic influences on these traits.32

  Status within the group is important for females too, but it doesn’t depend on their size or strength. A woman’s status is determined in part by her beauty. Of course, beauty isn’t the only thing that counts—nor are size and strength the only things that count for men—but these are characteristics that have been studied.

  Beauty is a woman’s bargaining chip in the mating game; a good-looking woman has a better chance of pairing up with a high-status mate. Having a high-status mate had evolutionarily relevant advantages for ancestral women. (I won’t elaborate, since so much has already been written on this topic.33)

  To make a wise decision in the mating game, a woman has to have a reasonably accurate idea of her own value in the mating market. If she overestimates herself, she might turn down offers that might not come her way again; if she underestimates herself, she might be too quick to say yes to the first guy who asks her. The evolutionary psychologist Robin Dunbar noted that women who marry men of higher social status tend to marry at a younger age,34 which suggests that women who haven’t yet found their prince may be holding out just in case he shows up later. But meanwhile the clock keeps ticking. Shakespeare, who understood so much about human nature, was aware of this dilemma. In As You Like It, a character tries to persuade a young woman named Phoebe to accept the advances of a low-status suitor by telling her that she is not very good-looking and hence has limited appeal: “Sell when you can: you are not for all markets.”35

  You see, there is a problem here, and Shakespeare recognized it. How does Phoebe know how good-looking she is? They had mirrors in Shakespeare’s time, but even a mirror can’t give a girl the information she needs. A boy can assess his size, strength, and speed relative to other boys by playing competitive games with them, but how does a girl figure out how pretty she is relative to other girls?

  What’s true for beauty is true for most of the qualities that affect people’s status and their desirability in the mating market. Size, strength, and speed turn out to be the exceptions rather than the rule. How would you know, if you were a child, whether you were well or poorly endowed with things like sense of humor and the ability to plan ahead? How would you know, if you lived in the days before schools existed, how smart you were? How would you find out how good you were going to be at tasks such as settling disputes, figuring out how to get somewhere and how to get back, or identifying edible plants? What you need is knowledge of how you compare with others, but in the absence of objective criteria, comparing yourself with others is difficult to do with any degree of accuracy.

  But other people can do it much more accurately. Other people can see you far more clearly than you see yourself. What matters in determining status in the group and desirability in the mating market is not how you see yourself but how other people see you—how they rate you in comparison with others in your age group. To guide you in picking a strategy that will serve you well in your adult life, the best information you can get is knowledge of how other people see you.

  Once again I find wisdom in the words of a social psychologist from an earlier era. Here’s what George Herbert Mead said in 1934:

  The individual experiences himself as such, not directly, but only indirectly, from the particular standpoints of other individual members of the same social group, or from the generalized standpoint of the social group as a whole to which he belongs.36

  Sociologist Gary Fine put it more succinctly: “The other is the mirror by which individuals learn of their selves.”37 What Fine meant by “the other” was what Mead called the “generalized other.” The added together or averaged other.

  So the status system, too, collects data and does statistics on them. What mat
ters is not what your parents tell you (they might think you’re gorgeous but so what?), or what your brother tells you (he’s just teasing), or what your best friend tells you.38 What matters is how you’re seen by the “generalized other.” It matters because it’s more accurate and hence has more predictive value than the opinion of any single individual.

  Of course, children have no way of knowing that the best thing to do is to figure out how other people see them and add up the data. But they don’t have to know it: they have a mental organ that does it for them. Mental organs, like physical ones, are the result of natural selection operating over thousands of generations, and natural selection is wiser than any child. Leda Cosmides and John Tooby explained how evolution—which is incapable of foreseeing the future but has a great deal of information about what happened in the past—can produce such devices:

  Natural selection does not work by inference or simulation. It takes the real problem, runs the experiment, and retains those design features that lead to the best available outcomes. Natural selection “counts up” the results of alternative designs operating in the real world, over millions of individuals, over thousands of generations, and weights alternatives by the statistical distribution of their consequences. In this sense, it is omniscient—it is not limited to what could be validly deduced by one individual, based on a short period of experience, it is not limited to what is locally perceivable, and it is not confused by spurious local correlations. It uses the statistical foundations of the actual lives of organisms, in the actual range of environments they encounter, under the statistical regularities they experience and, using alternative developmental programs leading to alternative designs, tests for the best solution.39