Anthropologists, sociologists and biologists have explored over several decades many factors that shape the likelihood of sexual coercion of women by men.
Such research cannot, of course, definitively explain the recent case in Cleveland involving Ariel Castro, who has been charged with abducting and raping three women over many years. But it does suggest avenues through which, on a societal level, sexual coercion – attempts to get sex by force — might be reduced in the United States and other countries.
Some biologists have argued that the proclivity for sexual coercion among men is merely a hand-me-down of human evolutionary history: They point to widespread sexual coercion among orangutans, a near cousin to humans on the tree of evolution. Other biologists, however, point out that sexual coercion is by no means universal in the animal kingdom. Even among other primates, male and female bonobos have much more egalitarian sexual relationships than do orangutans.
More to the point, as far as human societies are concerned, anthropologists have long documented differences in the extent of sexual coercion in different human societies. More than three decades ago, Peggy Reeves Sanday at the University of Pennsylvania found wide variations in sexual coercion in an analysis of 156 older societies. In some of these societies, sexual coercion was widespread. In others, it was nearly absent.
Sexual coercion, Sanday said — in a view backed by numerous feminist scholars — is shaped by cultural forces: "It is important to understand that violence is socially and not biologically programmed."
"Rape is not an integral part of male nature but the means by which men programmed for violence express their sexual selves," Sanday wrote in 1981. "Men who are conditioned to respect the female virtues of growth and the sacredness of life do not violate women. It is significant that in societies where nature is held sacred, rape occurs only rarely."
In a more contemporary analysis, researchers at the University of Hawaii studied patterns of pornography consumed in the United States, Norway and Japan, as a way to try to get at links between gender equality and sexual relations. The study looked at those countries in part because they fall on different points along a gender-equality spectrum that is tabulated by the United Nations and known as the Gender Empowerment Measure. (The measure "examines the extent to which women and men are able to actively participate in economic and political life and take part in decision-making," according to the U.N.)
At the time the study was conducted, Norway ranked first in the world in terms of gender equality, the United States ranked 15 and Japan ranked 54, according to the measure. The researchers found that Norwegian pornography was more likely than Japanese pornography to show women in empowered roles, with U.S. pornography falling in the middle.
To some people, that might seem like clear-cut evidence that increased gender equality leads to increased sexual empowerment for women and less sexual coercion, but the study also found that depictions of coercive sex in pornography are about as common in Norway as in other countries. The links between pornography consumption and actual sexual practice, moreover, are murky. Another study, for example, found that as pornography consumption has soared in Japan in recent decades, reported cases of sexual violence against women have fallen dramatically.
The link between gender inequality and sexual coercion is supported by another study conducted in sub-Saharan Africa that found higher levels of inequality linked to higher levels of coercion. But some scholars have noted that increased gender equality can also have different effects on sexual coercion over the short term than it has over the long term.
In the short term, greater equality might trigger a "backlash" effect, leading to changes in the status of women while, over the longer term, equality might be linked with lower levels of coercion. One analysis of 109 U.S. cities over three decades found that "the short-term effect of gender equality is an increased rape rate via increased threats to the status quo; whereas the long-term effect of gender equality is reduced rape via an improved climate toward women."
The study of the relationship between gender equality and sexual coercion is hobbled by the fact that sexual coercion and rape often happens behind closed doors, and does not get reported, let alone investigated. Definitions of sexual coercion, moreover, have been the subject of debate — many scholars point out that most sexual coercion of women happens in the context of existing relationships, including marriage, even though cases such as the Cleveland abductions are far more likely to attract media attention.
Other scholars also point to the role of power as a factor: In one analysis of 228 U.S. cities, researchers suggested that "in areas where women enjoy a higher absolute status, rape rates will be lower," meaning that access to power — rather than equality per se — might protect women against sexual coercion. In some ways, this finding meshes with research that suggests disadvantaged women in many societies are the ones who are at greatest risk of experiencing sexual coercion.
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. Transcript provided by NPR, Copyright NPR.