Sex without a condom was unthinkable to most college students in the 80’s and 90’s. Not so much today.

NPR reported.

Why Is Condom-Use Suddenly Dropping Among College Sophomores?

STEVE INSKEEP, HOST:

There’s research about sex in college – new research – and also on the precautions students of different ages and from different economic backgrounds do and do not take. NPR’s social science correspondent Shankar Vedantam told our colleague David Greene about it.

DAVID GREENE, BYLINE: So what have you brought us today?

SHANKAR VEDANTAM, BYLINE: Well, this is an analysis of unsafe sex at college campuses across the country, David. It comes from 20 schools ranging from Stanford and the University of Arizona to state schools, conducted by Jonathan Bearak. He’s a Ph.D. student at NYU. He finds that not all students in college are having sex, but students do become more likely to have unprotected casual sex as they progress through college. Here’s Bearak.

JONATHAN BEARAK: I find that seniors are about two-and-a-half times as likely to have unprotected casual sex when they hook up as freshmen are.

GREENE: Which is counterintuitive in a way because you expect that when you’re going through college, you’re becoming more mature, maybe more responsible, take more precautions, and this is suggesting the opposite’s true.

VEDANTAM: It is suggesting the opposite’s true. And in fact, there’s even more disturbing news, David, from the study. Bearak is also measuring how and when sexual practices are changing in college, and he finds something very interesting when it comes to unsafe sex. Now, he’s not talking about birth control and the risk of unintended pregnancy. He’s talking about the risk of sexually transmitted diseases. It turns out, David, there’s a sudden change in condom use at one specific point in college.

BEARAK: There’s an abrupt drop in condom use that occurs specifically between freshman and sophomore years, and thereafter, their condom use remains stable.

GREENE: OK – going from freshman to sophomore year, why does he think that’s such a moment of change?

VEDANTAM: Well, Bearak finds the shift in behavior among the students is largely driven by a shift in behavior among students from one specific demographic group. Students from different backgrounds don’t come to college with the same propensity to use condoms.