In Ego, Testosterone, and the Academy, Arnold Kling describes Summers’ talk as “as near a perfect example of judicious, thoughtful speculation as any imperfect human being might produce”:
Summers argues that to be a professor at a top university is to be at the very top of one’s profession, just as a corporate CEO is at the top of a firm. He says that to reach the top of a profession, one must dedicate an inordinate amount of time. He says that this need for professional dedication conflicts with family responsibilities for both men and women, but this tends to take more of a toll on women.Summers’ other point concerns statistical distributions. On a variety of attributes, statistical measures show that men have higher variance than women. Thus, if you look at the very top or at the very bottom of the distribution, you will find a larger share of men, while if you look in the middle, you will find a slightly larger share of women. He conjectures that this difference at the extremes exists for some attribute that is important in math and some branches of science. If to be at the top of one of those fields you need a genetic trait that is found only once in every 5000 or 10,000 people, and if rare genetic traits are more often found in men, then when you look at the top of those fields you will see more men.