Why do men and women have different psychological traits? In its own way, the course of the debate over this question has been fascinating.
At first, the prevailing view was that the Creator endowed each sex with different qualities suited to different tasks. Later, those differences came to be explained by evolution, though the basic perspective remained much the same.
After the Second World War, however, a very different view gained enormous influence. According to it, the differences were the product of social forces, especially childhood upbringing. The argument was that a hidden power structure—the so-called patriarchy—led boys to receive toy cars and girls to receive dolls. Without that influence, there would be no meaningful psychological differences between men and women.
Beginning in the 1980s, advances in neuroscience made it possible to study the human brain with much greater precision. Researchers found that the male brain functions differently from the female brain. Numerous experiments also demonstrated differences in the responses of infant boys and girls within the first days after birth. There are women with typically male-pattern brains (who are not necessarily lesbians), and there are men with typically female-pattern brains (who are not necessarily homosexual), but such cases are relatively uncommon.
Yet the story does not end there. Over the past generation, many scientists have once again confirmed that parents—even without intending to—treat boys and girls differently. From an evolutionary standpoint, this makes sense. If children are born with different mental dispositions, parents naturally respond to each in ways that make the most of those innate strengths. One might object that, if this theory is correct, parental behavior should vary not only by sex but according to children’s individual traits more generally. That is exactly what happens. Parents unconsciously adapt to the genetically influenced needs of different children.
Then came another striking discovery. The more egalitarian a society becomes, the greater the psychological differences between men and women appear to be. In Sweden, for example, the differences between male and female personalities are considerably larger than those found in the rural regions of Spain.
I would wager that the research still is not finished. That is what makes discovery so compelling. Even with something that seems so ordinary, we have not yet reached the end. There is always more to explore.