My commentary running today on the back cover of the Chronicle of Higher Education takes an unvarnished look at what can happen to the campus social scene when the female/male imbalance passes 60% female. That’s the gender imbalance campus admissions officers fear most, the threshold where you can feel a palpable difference on campus. What this means to the campus social scene is guaranteed to make parents of college-bound girls cringe a bit

Moving past 60% at some point triggers what biologists refer to as the operational sex ratio, which in the animal kingdom refers to the changes in mating habits that occur when one sex outnumbers the other. Humans are not immune, including college campuses.

Fyi: By the year 2015, the average graduating class from four-year colleges will be 60%. Trying to maintain healthy relationships between the sexes is one reason so many college admissions officers quietly grant admissions preferences to men (not that they would call them preferences. Rather, they draw large, overlapping circles to explain an admission policy that, in the end, favors men and discriminates against women). See my previous Chronicle commentary on that subject.

To date, this blog has focused mostly on what I see as the drivers behind this trend, boys falling behind in elementary school, never making up the lost ground and going to college at lower rates than girls. Gradually, however, I see the posts shifting more to the social impact of an education gap in the adult world — the search for “marriageable mates.”

(For more on that issue, sift through the “social consequences” and “college years” categories in the right column.)