The article Daring to Discuss Women in Science by John Tierney in the New York Times on June 7, 2010 purports to present a dispassionate scientific defense of Larry Summers’s claims, in particular by reviewing and expanding his argument that observed differences in the length of the extreme right tail of the bell curves of men’s and women’s test scores indicate real differences in their innate ability. But in fact any argument like this has to acknowledge a serious difficulty: it is problematic to assume without comment that the abilities of a group can be inferred from the tail of a bell curve….
[I]magine that you had a large group which you divided in half totally at random. At this point their bell curve of test scores looks exactly the same. Lets call one of the group “boys” and the other group “girls”. But they are two utterly randomly selected groups. Now lets inject the “boys” with a chemical that gives the ones who are very good already a burning desire to dominate any contest they enter into. And let us inject the “girls” with a chemical that makes the ones who are already good nonetheless unwilling to make anyone feel bad by making themselves look too good. What will happen to the two bell curves? Of course the upper tail of the “boys’” curve will stretch out, while the “girls’” tail will shrink in. It will look like the “boys” whipped the “girls” on the right tail of ability hands down, no contest. But the tail has nothing to do with ability. Remember they started out with the same distribution of abilities, before they got their injections. It is only the effect of the chemicals on motivation that makes it look like the “boys” beat the “girls” at the tail.
So, when you see different tails, you can’t automatically conclude that this is caused by difference in underlying innate ability. It is possible that other factors are at play — especially since if we were looking to identify these hypothetical chemicals we might find obvious candidates like “testosterone” and “estrogen”.
The first comment, by Sue VanHattum:
There is also the work of Janet Mertz et al, showing massive cultural variability in the percentage of women in the far right tail, making it clear that there is more nurture than nature in this.
Thank you for this post. I hadn’t known about Tierney joining Summers in this sexist nonsense.
So “ability” now has a new definition. It is a hypothetical state of equality that is disturbed by a natural difference between males and females. And the fact that this natural difference has an influence on performance is somehow “proof” that males and females are born equally able. By that kind of reasoning, the fact that I cannot see well enough to hit a major-league fastball proves that I belong in the Hall of Fame, along with Babe Ruth. If you’re looking for “sexist nonsense,” look no further than Rebecca Frankel’s hypothesis.