Another idea, Professor Is a Label That Leans to the Left:
The overwhelmingly liberal tilt of university professors has been explained by everything from outright bias to higher I.Q. scores. Now new research suggests that critics may have been asking the wrong question. Instead of looking at why most professors are liberal, they should ask why so many liberals — and so few conservatives — want to be professors.
A pair of sociologists think they may have an answer: typecasting. Conjure up the classic image of a humanities or social sciences professor, the fields where the imbalance is greatest: tweed jacket, pipe, nerdy, longwinded, secular — and liberal. Even though that may be an outdated stereotype, it influences younger people’s ideas about what they want to be when they grow up.
He added that the gender-typing of a field like physics might also partly explain the dearth of women in it, another subject that has provoked heated disputes.
To Mr. Gross, accusations by conservatives of bias and student brainwashing are self-defeating. “The irony is that the more conservatives complain about academia’s liberalism,” he said, “the more likely it’s going to remain a bastion of liberalism.”
In regards to the last paragraph, a friend of mine noted what it would sound like if you replaced “conservative” with “women” and “liberalism” with “maleness.” Or “conservative” with “black” and “liberalism” with “whiteness.” Certain types of diversity are easy to dismiss as trivial, or worthy of only academic analysis, while other forms are not brushed aside in this manner. Presumably the fact that sociology professors are invariably center-Left, resulting in a discipline that lacks in any conservative perspectives, is less of a worry than, for example, the lack of Asian Americans.
Another issue is that from what I recall the professoriate is extremely in favor of proactive attempts to race and gender balance the makeup of the students whom they teach, but are far more skeptical of the same considerations being directly inserted into the process of hiring or awarding tenure. I suppose university admissions officers are less objective than faculty hiring and tenure boards?
I do think that the explanation above is correct; if a smart person wants to make money they go into the corporate world, and if they want to “make a difference” they go in to non-profits and academia. I think there’s going to be positive feedback loops here as people sort in a manner where they select environments which suit them, and so intensify the tinge of particular professions or disciplines.