“Anywhere in the world that social psychologists see women or minorities underrepresented by a factor of two or three, our minds jump to discrimination as the explanation,” said Dr. Haidt, who called himself a longtime liberal turned centrist. “But when we find out that conservatives are underrepresented among us by a factor of more than 100, suddenly everyone finds it quite easy to generate alternate explanations.” - Jonathan Haidt, quoted in this New York Times article.When I read the quote on Friedman's page, I didn't immediately notice his reference to social psychologists and my first reaction was "I disagree with both the premise and the conclusion of this statement". Now that I see he is speaking just of social psychologists, I have to reign that in a little. Perhaps he is right about them - I don't know many social psychologists.
I am somewhat familiar with the literature on racial and gender disparities in the academy, though, and I do know that people who actually study this stuff don't think this at all. A major study in the early 1970s found that some of the gender gap was due to discrimination, but most work on the subject today doesn't really highlight discrimination as the source of disparities. I have a book review of an edited volume on the subject of black underrepresentation in the sciences coming out in the Journal of Negro Education - I'd have to revisit the book to say for sure, but I don't think any of the contributors raised the issue of discrimination in any substantial way. I'm currently working on a paper on gender disparities in the sciences. The subject of the paper is the extent to which these disparities pose a constraint on growth, but I'm of course reviewing the gender disparities literature and off the top of my head I can't think of a single study of the issue that suggests discrimination is the source of the problem. These analyses usually point to "pipeline" issues - explanations of why successively fewer minorities and women move on to higher levels of education to be considered for academic jobs. Work-life issues of course come up with women (you might call the incompatibility of some of these jobs with pressures of early motherhood "discrimination", but I'm not sure that's what Haidt has in mind here). Questions of adequate primary and secondary preparation obviously come up a lot with racial minorities. And in both cases there's questions of the impact of the lack of role models. But discrimination is the one thing that people seem to agree is not a deciding factor. You see some evidence in tenure decisions, if I recall, but it's by no means the dominant issue in this labor market.
Interestingly enough, when I clicked through to the New York Times article a lot of this research is quoted by the author of the article (not Haidt himself).
Larry Summers's comment on women in the sciences came up and Haidt had this to say: "“This was not a permissible hypothesis,” Dr. Haidt said. “It blamed the victims rather than the powerful. The outrage ultimately led to his resignation. We psychologists should have been outraged by the outrage. We should have defended his right to think freely.”". I think the backlash against Summers was overstated, but there are two things worth noting here: (1.) some of the harshest backlash again came from people that don't study this stuff, and (2.) the problem with Summers wasn't that he "blamed the victim" (although I guess he sort of did), but that he was spitballing on an issue he had no expertise in (did he really think nobody had thought of this possibility before?!) and which had already been investigated and rejected as a driving force.
So when Haidt says "our minds jump to discrimination as the explanation", take that with a big, fat grain of salt. Maybe his mind jumps to that. Maybe social psychologists' minds jump to that. Maybe the general public. But so what?
And now we come to political diversity in the academy. Now I've seen less work on this except for the Daniel Klein type stuff that just shows a disparity (as far as I know Klein has not produced any analysis tying this to discrimination). I have big doubts that this is really going on.
For starters, think about any job talk you've ever been to. I can only speak to job talks in economics departments and at the Urban Institute (mostly economists there, some public policy). I can't think of a single one that has offered me any clue as to the political background. Can you? I know the statistics (I read my Dan Klein!), so I could generate an expected value. But any given person is going to just be a guess. Something tells me the issue doesn't come up in the interviews either (I know no one ever asked me about it, and I've never asked anyone about it in the cases where I've interviewed a job candidate). So the idea that there is discrimination against libertarians and conservatives already is running into trouble with the smell test. How does anyone know?
You would only really know in an obvious way if the job applicant's politics comes out in their academic work. And of course such a person is going to be less likely to be hired - why would you hire someone with such poor research practice!
If it's that hard to pick out a conservative or libertarian relative to picking out a black guy or a woman (relatively easy, in my experience), and if we don't find discrimination as a hugely important factor in explaining racial and gender disparities, I seriously doubt it even registers for conservatives and libertarians. There are much better potential explanations out there. The first two here loom large as explanations of racial and gender disparities, the third and fourth are better at explaining specifically why conservatives and liberals are so outnumbered:
Pipeline issues: as with minorities and women, something is keeping conservatives and libertarians from progressing through the academic pipeline. As with minorities and women, this could be a combination environmental pressures and personal preferences, and of course preferences on these sorts of things are going to be endogenous. Women don't get told they can or should be scientists when they are young - conservatives don't get told they can or should study human evolution or the determinants of poverty and inequality when they are young, etc.
Inadequate preparation: This is a big problem for racial minorities. It is very hard to get minority professors when the primary education that most minority children pass through is so broken. This is not to say everything is peachy once you get to the post-secondary level: it's not. But if your flow into the post-secondary level is limited in the first place that poses a real problem. This might be a problem for conservatives too if conservatives come from places with weaker academic preparation. If you just think of an electoral map, they do seem to well represented in places where the school systems are worse.
Conservatives and libertarians might be dumber: Notice "might" be. And this isn't blaming the victim, it's sympathizing with the victim. It appears to be less of a problem with libertarians than with conservatives. As with claims about the abilities of women and minorities, this needs to be thoroughly investigated before it's just accepted, but the point is that there is an inherent plausibility to this where there is an inherent implausibility to thinking that there are such differences for women and minorities. You choose to be a conservative or libertarian. You select into those groups. You evaluate arguments and make assessments. You don't choose to be a woman, and you don't choose to be a racial minority. Even people that switch sexes arguably don't "choose" that - they're making a correction to align with a reality that they never chose. So why wouldn't intelligence influence ideological or political affiliation - something you choose? Shouldn't intelligence influence things where we make evaluations and choices? I'm not saying it's a determinate factor. Value systems come in as well (equally smart people with different values are going to align differently politically), but because you actually select into political viewpoints in a way that you don't select into sex or race or sexual orientation, the determinants of that selection process ought to also be considered as potential legitimate determinants of success in academia.
Conservatives and libertarians aren't underrepresented in academia - they are changed by academia: This again has to do with the fact that you select into political ideologies in a way that you don't select into race or sex. The thinning of the conservative/libertarian ranks as you move down the academic pipeline might say something about what understanding more about the world does to a person's political ideology. You can see this process historically too: as we as a species learn more about our world, we as a species get more "progressive" as the term is understood today. The scientific revolution seems to be closely related to the emergence of liberalism and the industrial revolution, after all. It fits my story - I was conservative in high school, was a libertarian that dropped all the stuff I didn't like about conservatism when I moved into college, and as I learned more and more economics I became much less libertarian (some people may become more libertarian, but they probably have different starting points). I'm not sure what I am now, but I don't think I'm a conservative or libertarian.
Don't get bent out of shape if you're a libertarian or conservative. There are always idiosyncratic forces acting on any given case. No one is calling you dumb. You have to step back and think of the problem more generally:
1. Is discrimination a major determinant of the lack of women and racial minorities in academia? The answer seems to be "no" - it's a bigger issue in other labor markets but doesn't seem to be in this one.
2. Sex and race are much more visible than political ideology. Is it plausible that a less visible trait is more likely to be discriminated against than a more visible trait? My suspicion is "no".
3. You can select into and out of political ideology in a way that you can't select into and out of sex and race. Are these selection effects relevant for considering the difference between sex and race discrimination and ideological discrimination? I can't imagine how the answer is not "yes".