DAVID GREENE, HOST:
Police are still investigating how Ariel Castro allegedly abducted and repeatedly raped three women in Cleveland. There are many details of this case that remain murky. A few days ago, we thought Castro's two brothers might have played a role in the abductions. But police now believe those men were not involved. Still, even as this investigation unfolds, it appears this is a case involving a man getting sex by force.
We've called in NPR's Shankar Vedantam, who regularly joins us to discuss social science research, to talk about some of the research into factors that might predict sexual coercion. Shankar, thanks for coming in.
SHANKAR VEDANTAM, BYLINE: Happy to be here, David.
GREENE: So are there patterns that scientists can see, that might predict this kind of awful behavior?
VEDANTAM: You know, it's a big and complicated topic, David. Anthropologists find, in studies of all the cultures, a fairly wide range; where in some societies, you have a lot of sexual coercion and in some societies, you have very little. Three decades ago, Peggy Reeves Sanday, at the University of Pennsylvania, studied 156 of these older societies. And what she found was that sexual coercion was widespread in some and rare, or almost even absent, in many others.
And what she found was that norms seem to play a very important role. Do you live in a society where sexual coercion is condoned, or do you live in a society where such coercion is condemned?
GREENE: OK. Well, the United States - I mean, we're a developed, industrialized country where this kind of behavior is condemned. I mean, in a society like that, what do we know?
VEDANTAM: Well, feminists have long explored the idea that gender equality might be linked to sexual coercion, and that different levels of gender equality might predict sexual coercion. And there's evidence to back this up. You know, at the University of Hawaii, Elaine Hatfield and a couple of graduate students published a paper last year that analyzed pornography in three different countries. They looked at the United States, Norway and Japan.
And they picked those countries because according to various international rankings, Norway is No. 1 in the world, in terms of gender equality. The United States comes in about 15. And Japan ranks about 54. In this analysis, what they found was that the kinds of pornography that were popular in these different countries was actually quite different, and that pornography in Norway tended to show women in more empowered roles, compared to pornography in Japan; with the U.S. falling somewhere in the middle.
There's another study in sub-Saharan Africa, for example, showing that gender inequality seems to be linked with more sexual coercion. And so that lends support to the idea, too, that there are some connection here between equality and sexual relationships. But I have to say, there's also conflicting research on this. It's also possible that as societies transition to greater equality, initially what you might see is an increase in sexual coercion.
GREENE: So Shankar, are we talking about a backlash - I mean, men resent the fact that women are equal in their society?
VEDANTAM: I think that's the theory that the researchers are working with. But I think it's also true, David, that what they say is that in the long term, higher levels of gender equality seem to be linked with lower levels of sexual coercion.
GREENE: OK. What about the situation in the United States?
VEDANTAM: I looked at one study by a researcher called Kimberly Martin, at the University of Missouri, and she analyzed 228 U.S. cities. And what she found, interestingly, was not that gender equality reduced sexual coercion. In other words, she didn't find lower rates of sexual coercion in cities with higher levels of gender equality. She just found that having power protected women from sexual coercion. What the study seems to suggest is, the women with the power are going to be protected, whereas the women without the power are at increased risk.
GREENE: And more vulnerable.
GREENE: A lot of research, and it sounds like they're no clear answers; but really interesting hearing about this. Shankar, thanks for coming in.
VEDANTAM: Thank you, David.
GREENE: Shankar Vedantam - he regularly joins us to talk about social science research. And you can follow him on Twitter @hiddenbrain. And you can also follow this program @nprgreene, @nprinskeep, and also @morningedition.