Via Memeorandum, I learned about a new study by sociologists which sheds new light on a vexing question -- why do many college professors lean so predominantly to the left?

The answer seems disappointingly simple -- liberal want to be professors, while conservatives don't:

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 Even though that may be an outdated stereotype, it influences younger people's ideas about what they want to be when they grow up.

What also caught my attention was the wonderful accompanying graph showing the proportions of liberalism, moderatism and conservatism in the different occupations:

Now that's a nice chart! As a former nightclub owner (who necessarily had to learn to be a bartender), it didn't escape me that the largest "moderate" group consisted of bartenders. Interestingly, they are overwhelmingly moderate to conservative, but only a small percentage will go so far as to actually call themselves "conservative." If you're a bartender, your goal is to keep the customers as relaxed and happy as possible, and expressing ideological rigidity of any sort is just not wise. Not if you want to keep 'em happy, and get nice tips. Best thing to do is agree a lot, and take as broad a view of things as possible. And while liberal bartenders outnumber conservative bartenders by a wide margin, I suspect this would tend more to reflect a custom and practice of "fitting in" with the clientele than heart-felt ideological convictions, and I would be willing to bet that your average liberal bartender would be more tolerant of a conservative customer than would a college professor be tolerant of a conservative student. A successful bartender is unlikely to see his job as indoctrination.

I don't know why they left the stereotypically "gay" jobs off the list, though. Funny, because the authors touch on the nursing profession -- males nurses of course being a source of laughter:

....For instance, less than 6 percent of nurses today are men. Discrimination against male candidates may be a factor, but the primary reason for the disparity is that most people consider nursing to be a woman's career, Mr. Gross said. That means not many men aspire to become nurses in the first place -- a point made in the recent Lee Daniels film "Precious: Based on the Novel 'Push' by Sapphire." When John (Lenny Kravitz) asks the 16-year-old Precious (Gabourey Sidibe) and her friends whether they've ever seen a male nurse before, all answer no amid giddy laughter.

Nor are lawyers. Out of all the things I have done in my life (I have worked construction, as an auto mechanic, a plumber, an electrician, and attorney), only bartending is listed. What's up with that? And where's the military?

Lots of boys want to grow up to be auto mechanics and soliders, right? As to those who want to grow up to be hairdressers, well... Many parents would raise an eyebrow or two over that one, although John Waters's classic Female Trouble created a tortured exception in the form of Edith Massey, who played a woman whose nephew was straight and wanted to be an auto mechanic, but was forced into hairdressing by Aunt Ida who kept trying to turn him gay.

Her efforts failed miserably, and her son eventually ran away to Detroit to join the auto industry.

The study left out cowboys. So did I. Probably because I think Female Trouble does a better job with stereotypes than Brokeback Mountain.

MORE: I mistakenly called Aunt Ida the "mother." Error corrected.