By Satoshi Kanazawa and Kaja Perina

In an earlier review of fellow PT blogger Susan Pinker’s book The Sexual Paradox: Troubled Boys, Gifted Girls and the Real Difference Between the Sexes, we ponder why it is that so many highly successful women experience the “ ” – the persistent feeling that, despite their well-deserved success and accolades, they are somehow frauds and will soon be exposed – while very few comparable men experience it. We may have an answer.

The term “imposter syndrome” was originally coined by Pauline Clance and Suzanne Imes in their landmark 1978 study of 150 highly successful professional women in various fields. Pinker describes Clance and Imes's findings: “Despite accolades, rank, and salary, these women felt like phonies. They didn’t believe in their own accomplishments; they felt they were scamming everyone about their skills.” Thirty years later, Pinker in her own 2008 book interviews many highly successful women who also feel the same way about their success. What is remarkable about the imposter syndrome is the massive difference: Many successful women experience it, while very few successful men do. Pinker elaborates on this point in a recent article for Psychology Today magazine. And in the second part of the three-part review of Pinker’s book, we end with the question: “Why do so many highly accomplished women feel they are frauds, imposters, and phonies when their male counterparts don’t?”

A couple of possibilities have since occurred to us. First, “success” in advanced industrial economies like the United States is defined purely in male terms, not in female terms. When we think of “highly accomplished successful women,” we think of CEOs of major corporations, politicians, and leaders in their respective fields. In other words, we think of women who make a lot of money, exercise political power, or otherwise achieve very high status in a clearly defined hierarchy. Throughout evolutionary history, status, political power, and resources have been what defined success among men, not among women.

When we think of “successful women,” we do not think of mothers who invest in and raise their children well, friends who offer help to friends in need, neighbors who work tirelessly for the common good of the neighborhood, or sisters who help sisters and brothers raise their children, even though this is something that women have always done throughout evolutionary history. When we think of “successful women,” we don’t think of the Octomom, Nadya Suleman, even though, in purely reproductive terms, she is probably the most successful person in the United States today. We cannot think of any other woman – or man – who has produced 14 children. Nadya Suleman is 14 times as successful as Hillary Clinton is, but Suleman is not the one we have in mind when we think of “highly accomplished successful women.”

We suspect that one reason why so many women but very few men experience the imposter syndrome may be because the definition of success in the evolutionarily novel contemporary society is biased toward males. Nobody recognizes women who are successful in female terms. So part of the problem may be definitional. If we are right, then any man who receives worldwide accolades as a wonderful father or friend should also experience the imposter syndrome, even though we would not expect anyone to receive such recognition, once again, precisely because “success” in our society is defined in male terms.

Second, success usually does not come easily for anyone, man or woman. In order to achieve high status and recognition in any , one must endure a long process of trial, during which one faces a lot of , rejection, disapproval, and ostracism from others, especially those that one must compete against and beat. This is true of both successful men and women, but we believe such reactions from others may be more difficult for women to handle than for men.

Throughout evolutionary history, our ancestors practiced what is known as female exogamy. It means that, when girls reach , they leave their natal group in which they were born and raised, migrate to a neighboring group, and marry into it, while boys remain in their natal group and spend their entire lives with their kin. Every social species must practice either female or male exogamy in order to avoid incest; at puberty, either the males or the females must systematically leave their natal group and disperse. Molecular genetic evidence suggests that humans practiced female exogamy, not male exogamy.

The human history of female exogamy means that adult women have always lived among genetically unrelated strangers, whereas adult men have always lived among genetic kin. This simple fact should have created major differences in the male and female evolved human nature. One such difference may be how men and women respond to rejection and disapproval.

When men are rejected and disapproved throughout evolutionary history, such reactions necessarily come from their genetic kin. Family members may fight with each other, but, in the end, there is only so much you can do to reject them; after all, they are family, and genetic relatedness means a lot. It is a major basis of in all species. In contrast, when women are rejected and disapproved, the same reactions come from men and women who are genetically unrelated to them. If they hate you enough, they may ostracize you and expel you from the group. Your only genetic link to the group are the children you have produced with the man you married, but even he is ultimately a genetic stranger living among his genetic kin. And – dissolution of a committed long-term relationship – is unfortunately a human universal and probably happened throughout evolutionary history.

This may be why women have been evolutionarily designed to rejection and disapproval much more than men do. Combined with the fact that success itself is defined in male terms, the history of female exogamy may potentially explain a huge sex difference in the experience of the imposter syndrome.