Intellectual capital and opinion

A 1999 study (pdf) has some striking results about US academic political adherence by faculty. The ranking in terms of percentage of self-specified conservatives is:

Political science 2%
English 3%
Philosophy 5%
Theology/Religion 5%
Music 8%
Sociology 9%
History 10%
Physics 11%
Linguistics 11%
Communications 14%
Performing Arts 16%
Biology 17%
Mathematics 17%
Engineering 19%
Computer science 26%
Chemistry 29%
Education 29%
Economics 39%
Business 39%
Nursing 47%

Average 15%

Using the labels liberal and conservative in their (somewhat odd) US usage, conservatives are most concentrated in the caring professions (Nursing, Education) and other social-practicality disciplines (Economics, Business).  Liberals are most concentrated in the social-abstraction disciplines (Political science, English, Philosophy, Theology/Religion, Music, Sociology, History) with various hard sciences (Physics, Biology, Mathematics, Engineering, Computer Science, Chemisty) and some social-abstraction disciplines (Linguistics, Communications, Performing Arts) being intermediate cases.

This pattern seems to me to be explicable. Particularly if one compares to the wider society.

General US public self-identification
Liberals 18%
Conservatives 36%
Democrats 34%
Republicans 31%

Faculty self-identification
Liberals 72%
Conservatives 15%
Democrats 50%
Republican 11%

(Greens and Libertarians probably also have disproportionate faculty support).

Faculty are about as likely to be partisan identifiers, but far more likely to be ideology identifiers, than the general public.  As ideological opinions are more characteristic of faculty, it can reasonably be expected that they matter more among faculty than in the general population. But the patterns are also wildly different between public and faculty, with striking levels of opinion hegemony among faculty.

Political beliefs per se often have little direct feedback from their wider social effects to the believer.  But if political beliefs are status markers, then having particular political beliefs may have social consequences in particular milieus leading to selection effects (including self-selection effects).  This effect is likely to be strongest where (1) the milieu is concerned with social matters and (2) lacks personal-consequence feedback from the wider social consequences of beliefs (an effect that tenure would obviously increase).  Conversely, it is likely to be weakest where feedback on the wider social consequences of beliefs is strongest, reducing the power of opinions as status-markers.

So, if (US) liberal beliefs are status markers, selection processes are likely to be strongest in social abstraction disciplines and weakest in social practicality disciplines, yet still stronger in the faculty generally than the wider population.  Not least because being insulated from “vulgar commerce” can be taken to be an inherent point of higher moral status (the "ivory tower" as bastion of moral cleanliness), provided that commerce is taken to be a marker of moral inferiority (which writing about the evils of capitalism would tend to do).  Such would shift the entire faculty leftwards but to varying degrees depending on the discipline for the reasons discussed.  Hence the above results.