I blogged yesterday about Stanford neurobiology professor Ben Barres' article in Nature; I thought his argument was quite interesting, and may be generally quite right as a scientific matter (my correction was only focused on one error, which may not affect the bottom line). Yet the following passage from the article troubles me (emphasis added):

Steven Pinker has responded to critics of the Larry Summers Hypothesis by suggesting that they are angry because they feel the idea that women are innately inferior is so dangerous that it is sinful even to think about it. Harvard Law School professor Alan Dershowitz sympathizes so strongly with this view that he plans to teach a course next year called 'Taboo'. At Harvard we must have veritas; all ideas are fair game. I completely agree. I welcome any future studies that will provide a better understanding of why women and minorities are not advancing at the expected rate in science and so many other professions.

But it is not the idea alone that has sparked anger. Disadvantaged people are wondering why privileged people are brushing the truth under the carpet. If a famous scientist or a president of a prestigious university is going to pronounce in public that women are likely to be innately inferior, would it be too much to ask that they be aware of the relevant data? It would seem that just as the bar goes way up for women applicants in academic selection processes, it goes way down when men are evaluating the evidence for why women are not advancing in science. That is why women are angry. It is incumbent upon those proclaiming gender differences in abilities to rigorously address whether suspected differences are real before suggesting that a whole group of people is innately wired to fail.

What happens at Harvard and other universities serves as a model for many other institutions, so it would be good to get it right. To anyone who is upset at the thought that free speech is not fully protected on university campuses, I would like to ask, as did third-year Harvard Law student Tammy Pettinato: what is the difference between a faculty member calling their African-American students lazy and one pronouncing that women are innately inferior? Some have suggested that those who are angry at Larry Summers' comments should simply fight words with more words (hence this essay). In my view, when faculty tell their students that they are innately inferior based on race, religion, gender or sexual orientation, they are crossing a line that should not be crossed — the line that divides free speech from verbal violence — and it should not be tolerated at Harvard or anywhere else. In a culture where women's abilities are not respected, women cannot effectively learn, advance, lead or participate in society in a fulfilling way.

As best I can tell, Prof. Barres is arguing that those like Larry Summers who believe that the disparate representation of men and women in certain fields flows partly from biological cognitive differences ought not be allowed to express their views, at least at the university. Such speech, he argues, is not "free speech" but instead "verbal violence" and "should not be tolerated at Harvard or anywhere else." What's more, he seems to be distancing himself from the view that this lack of "tolerat[ion]" should extend only to counterargument (though he himself engages in this): This view, he says, is what "Some have suggested," while "In [Barres'] view," statements like Summers' should not be tolerated and should instead be treated like verbal violence (and violence is usually fought through tools other than counterspeech) rather than speech.

This strikes me as an extremely troubling proposition. Prof. Barres may have the better of the scientific argument — but here he seems to be suggesting that we shut down the scientific argument, by refusing to "tolerate[]" or treat as "free speech" contrary views. This (1) risks suppressing true counterarguments to Prof. Barres' views, if it turns out that Prof. Barres' is mistaken (at least in part).

It also (2) undermines the credibility of Prof. Barres' own views, even if they're completely correct. As a layperson, I don't know who's right on this debate. Prof. Barres may be sure based on his own extensive research, but naturally most of the rest of us — including the rest of the colleagues who are deciding whether to condemn statements like Prof. Summers' and "not [to] tolerate[]" such statements in the future — can't be.

If after decades of open and tolerant discussion Prof. Barres' view emerges as the dominant one, laypeople like us can have considerable confidence in its accuracy. (This is why, despite our general openmindedness, we would indeed have little social and professional tolerance for someone who urges the phlogiston theory of fire or something that's been similarly broadly discredited.) If, however, we know that Prof. Barres' view prevailed but only in a debate in which rival views were not tolerated, and were punished as "verbal violence" rather than protected as "free speech," then we can have no confidence in the view's accuracy. For all we know, the view may be largely wrong, and contradicted by important data, but that data has been hidden from us by speech codes or by scientific peer pressure.

Of course, Prof. Barres' position (3) would also set a tremendously dangerous precedent for other fields. Prof. Barres seems to also argue that academics shouldn't be allowed to argue about whether there are important innate racial differences, or innate sexual orientation differences. Apparently one can investigate and debate whether sexual orientation is partly or largely genetically caused, I take it, but not whether it may be correlated with other genetic traits. There'd also be some unclear limits on criticism of religion: Literally his argument is only that faculty may not be allowed to tell their students (or presumably give speeches, such as Summers', that students may hear about) "that they are innately inferior based on ... religion," and it's not clear what innate inferiority based on religion might be (though I have seen discussion of whether a tendency towards religiosity might indeed be genetically linked). But the logic of his argument would suggest that harsh criticisms of certain religious ideological systems that may make adherents of those systems feel unwelcome would also be prohibitable. And those are just Prof. Barres' specific examples; the same arguments could apply to suppressing a wide range of supposedly dangerous academic viewpoints.

Now I understand part of people's concern about discussion of innate gender differences: If certain students get alienated or dispirited enough by such statements, for instance because they're insulted by them or because they wrongly infer that such assertions about broad populations mean that they themselves have no future in some field, they may stay away from certain fields, or certain universities. I do think there are social factors that push many girls and women away from science and engineering, and I think those factors are costly for universities and for society as a whole. Universities and other institutions should work hard to diminish these factors, and to encourage people with mathematical and scientific aptitude — boys and girls alike — to go into math and science (plus encourage people without such aptitude to nonetheless get some decent grasp of the basics).

Such efforts on the part of university, however, should not come at the expense of constraining academic debate about very important scientific issues such as the interaction of gender and cognition. If some students are offended by scientific theories faculty propose, they should be taught to respond with research, analysis, and (if the theories are wrong as well as offensive) rebuttal, not alienation. If some students are dispirited by the implications of those theories, they should be taught to understand the limits of those implications. If some students are concerned about sex discrimination both in society and in their institutions, they should certainly fight it (including by researching the matter, and seeing to what extent any observed disparities flow from discrimination, and to what extent, if any, they may flow from genuine biological differences).

But students should never be taught that apparently dangerous ideas about what is true ought to be fought through suppression, rather than investigation and (when called for) rebuttal. And that brings us to one other problem with Prof. Barres' proposal: (4) It would teach the next generation of scientists the wrong approach to science — an approach that urges them to premature certainty rather than constant doubt and inquiry, and an approach that urges them to suppress contrary views rather than rebut them. That's a poor service to all students, whether male or female.