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. It turns out students from disadvantaged backgrounds are more likely to use condoms when they arrive in college compared to students from more privileged backgrounds. Soon after joining college, however, students from these poor backgrounds start behaving much more like their privileged peers. So effectively, students from rich families seem to be serving as role models for students from poor families. Except in this case, they're not serving as good role models.
BEARAK: It's ironic because students are actually learning bad behaviors, and they're learning it from the group of students who policymakers would generally say they want the least advantaged students to emulate.
GREENE: Why would students from privileged backgrounds use condoms less often than those from less privileged backgrounds in the first place?
VEDANTAM: Well, you know, there could be multiple reasons for that, David. It may be that poor students have been repeatedly warned about the risks of sexually transmitted diseases or unintended pregnancies. It may be that they actually perceive a higher risk of sexually transmitted diseases in their communities. Previous work has shown that your perception of risk is shaped by the community in which you're embedded. And it may be that people who come from poor communities actually come to college perceiving a higher risk for sexually transmitted diseases.
By contrast, you know, David, if you come from a well-to-do background, you may feel sexually transmitted diseases are not really something that I need to worry about. Now, one year after joining college, this new community, students from poor backgrounds seem to feel their risk factors have changed, and they start to behave more like their privileged peers.
GREENE: Well, so, Shankar, we hear about messages given to college students about practicing safe sex. I mean, does research like this going to sort of change the thinking when it comes to that?
VEDANTAM: Yeah, you know, Bearak thinks there might be two implications from the study, David. One is that, you know, people of privilege are often prone to preaching to the poor. In this case, it sounds like rich parents might want to make sure their own kids are hearing the message about safe sex and being careful about their health choices. The other thing, David, is psychologists might want to ensure that students from privileged backgrounds are being targeted for safe-sex messages because at least in this case, they're the ones who seem to be setting a bad example.
GREENE: All right, Shankar, interesting stuff as always. Thanks a lot.
VEDANTAM: Thank you, David.
INSKEEP: That is, of course, Shankar Vedantam, who regularly joins us to talk about social science research. You can find him on Twitter at @HiddenBrain. Follow this program at @NPRinskeep, @nprmontagne, @nprgreene and at @MorningEdition. This is NPR News. Transcript provided by NPR, Copyright NPR.