This month’s Cato Unbound has another interesting subject, this time on the decline of men. In the lead essay, Kay Hymowitz runs through the mass of ways men are starting to fall behind women. Many of the statistics were a surprise to me. Take the following:

In an analysis of recent census data, Reach Advisors found that childless twentysomething men now earn 8% less than their female counterparts in 147 out of 150 of American cities. That’s despite the fact that college-going women major in subjects that tend to lead to lower paying jobs. Young single men are less likely to own a home than women. While on average men continue to earn more than women, their wages, unlike those of women, have stalled.

In her response essay, Jessica Bennett counters that women are still behind in many areas:

By the time women enter college, studies show they’ll have given up many of their leadership roles. The rise of the knowledge economy may have multiplied opportunities in other fields (Hymowitz sites public relations, graphic design, and management). But women will still make up just a third of business-school students and barely a quarter of law firm partners. …

Women still have trouble penetrating the highest rungs of the corporate world: they are also just 3 percent of Fortune 500 CEOs, less than a quarter of politicians, and just 22 percent of the leadership positions in journalism.

Between the two essays, there is a thread that young women are overtaking men in many areas, while not yet penetrating the top.

Bryan Caplan notes one potential explanation, namely that women seem to have less variance in traits than men in many dimensions:

But isn’t the obvious explanation just that men have higher variance in general?  This is easiest to prove for cognitive ability - see Garett Jones' review of the evidence.  But it also seems very plausible for interests and obsessiveness.  Anyone can start a blog, but men are much more likely to do so.  The reason, I’ll warrant, is that the male distribution of ego has a right tail that stretches far into the horizon.<

From an evolutionary perspective, the higher variance for men makes sense. In a winner takes all competition for women, men at the top can have many children. Meanwhile, women are constrained in the maximum of number of children they can have. The jackpot of being the best male far outweighs the cost of being the worst. Genghis Khan was so reproductively successful (as was his grandson Kublai Khan) that one in 200 men globally are direct descendants along the male line and hence carry his y-chromosome. Such success would be impossible for a woman. Being a rich, successful male could buy additional access to mates and reproductive success that being a rich, successful woman does not. The evolutionary incentives are stacked in favour of the man seeking those top positions.

An evolutionary perspective also assists in the following, in which Hymowitz asks whether the loss of the historical male role as provider has played a part in the “decline of men”:

Consider another recent study by S. Alexandra Burt at Michigan State University. Burt followed 289 pairs of male twins for 12 years, between the ages of 17 and 29. More than half of the twins were identical. She found that men who had shown less antisocial behavior as adolescents were more likely to marry as they got older, which argues for self-selection. But she also found that a married twin had fewer antisocial behaviors—aggression, irritability, financial irresponsibility, and criminal involvement—than his unmarried brother. This suggests there is some truth to the very unfashionable idea that marriage helps to discipline men.

Less anti-social men have a higher probability of getting married - they are better at providing something women want. In the case of the anti-social, unmarried brother, their risk taking activity reflects that, having failed to initially get a mate, they move to progressively riskier activity until they succeed, die or are jailed, or they somehow survive as their testosterone fades into old age. Marriage helps discipline the man by providing the man with his objective.

Ultimately, I wonder how long the trend that triggered the essays will last. Many women, as they have for the last 40 years, are choosing to remain childless. The genes of these women, and any inherent traits that result in a predisposition to remain childless, disappear from the gene pool. The women that form future generations are the children of mothers who chose to take time out to have children despite the growing options for their own careers. As Hymowitz notes:

The point is that today, with the important exception of the technical and financial sector, younger women (that is, childless women, an important caveat) have shown they can easily be men’s equals, and possibly even their superiors, in the knowledge economy.

That important caveat will be applied more and more in the future. In that case, some of the gap will remain. (And as an aside, I recommend that you read all of Hymowitz’s essay - there are a lot of interesting ideas in it)

Update: A follow-up post is here.