I want to make a few followup points regarding yesterday’s post about the gender gap in the sciences.
Just to recap, the “Larry Summers hypothesis” is the idea that differences in intrinsic intellectual ability can explain the underrepresentation of women in academic science. More specifically, the proposed explanation is that, even if there’s no difference in average ability, men tend to have intellectual ability (as measured by scores on various tests) that scatters more widely than women. That means that men populate the very extreme highs and lows of the distribution much more than women. If being a successful scientist requires being in the extreme high end of this distribution, then that might explain the gender gap.
I don’t think this is likely to be a significant part of the explanation, for reasons I tried to explain. The biggest one is that I don’t think that success in a scientific career is sufficiently strongly correlated with intelligence (where the “intelligence” is defined to mean “the thing that the tests in question measure”). To be more specific, I certainly don’t think that it’s strongly correlated with presence in the high-end tail of the intelligence distribution, which is where the gender differences supposedly lie.
If we were just trying to explain the preponderance of men among Nobel Prize winners, maybe a case could be made for this effect (although even then I’m not sure). But in fact the gender gap shows up much earlier and grows at each step. (The “leaky pipe” is the usual metaphor here.) More men than women major in physics; the ratio skews further at the Ph.D. level, still further at the level of faculty jobs, and even further among tenured faculty. If you think that all of this is because of effects in the top 1% tail of the intelligence distribution, I’m afraid you’re making a flattering overestimate of the physics community’s intelligence. We’re tolerably bright, but not that bright.
But there are a couple of things I want to make clear:
1. People sometimes use your attitude about the Summers hypothesis as a proxy for your attitude about all sorts of other things: if you disbelieve the Summers hypothesis, you must believe in the mind as a blank slate, with no room for intrinsic biological differences between the sexes. Conversely, if you believe in the Summers hypothesis, (according to some) you must be a sexist. Those attitudes are ridiculous. In particular, although I think the Summers hypothesis is probably wrong, I think that that intrinsic cognitive differences in the sexes are quite likely to be real and may explain all sorts of other phenomena. I’m even generally sympathetic to the evolutionary psychology point of view, which is anathema to a lot of people who argue against the Summers hypothesis.
(Incidentally, if I may play armchair psychologist for a moment, it seems to me that the authors of that NOVA blog post, which got me started on this whole subject, are making this error: they saw Tierney as sympathetic to the Summers point of view and concluded that he must believe in the whole constellation of despised ideas that they associate with that point of view. I can’t see any other reason they would have so egregiously misrepresented what he said.)
2. I don’t think that adherents of the Summers hypothesis are bad people, and I don’t think that the hypothesis should be ruled out of the bounds of polite discussion (as many people seem to). It’s an a priori possible explanation of the observed data, which is either true or false. It has the right to a hearing, and its probability of being correct can and should be judged on empirical grounds, like any other hypothesis. Personally, I think it must be found wanting on those grounds. But it should not be ruled out a priori because we don’t like its social or political implications.
3. It may seem to follow from point 2 that Larry Summers got a raw deal, but my sympathy for him is extremely limited. If you’re a politician (and yes, a University president is a politician), then you should know better than to speak off the cuff about an extremely controversial topic about which you clearly have given very little thought. He made a boneheaded move in raising the subject the way he did, and he got what was coming to him. Moreover, as is often the case when politicians are brought down by gaffes, this one probably wouldn’t have brought him down if he didn’t have a history of alienating people.