IT USED TO BE TOUGH to get porn. Renting an X-rated movie required sneaking into a roped-off room in the back of a video store, and eyeing a centerfold meant facing down a store clerk to buy a pornographic magazine. Now pornography is just one Google search away, and much of it is free. Age restrictions have become meaningless, too, with the advent of social media—one teenager in five has sent or posted naked pictures of themselves online, according to the National Campaign to Prevent Teen and Unplanned Pregnancy.

With access to pornography easier than ever before, politicians and scientists alike have renewed their interest in deciphering its psychological effects. Certainly pornography addiction or overconsumption seems to cause relationship problems [see “Sex in Bits and Bytes,” by Hal Arkowitz and Scott O. Lilienfeld; Scientific American Mind, July/August 2010]. But what about the more casual exposure typical of most porn users? Contrary to what many people believe, recent research shows that moderate pornography consumption does not make users more aggressive, promote sexism or harm relationships. If anything, some researchers suggest, exposure to pornography might make some people less likely to commit sexual crimes.

Does Porn Harm Women?

The most common concern about pornography is that it indirectly hurts women by encouraging sexism, raising sexual expectations and thereby harming relationships. Some people worry that it might even incite violence against women. The data, however, do not support these claims. “There’s absolutely no evidence that pornography does anything negative,” says Milton Diamond, director of the Pacific Center for Sex and Society at the University of Hawaii at Manoa. “It’s a moral issue, not a factual issue.”

In 2007 researchers at the University of Zagreb in Croatia surveyed 650 young men about their pornography use and sex lives. As they reported in the Archives of Sexual Behavior, the scientists found that users of mainstream, non­violent pornography were neither more nor less sexually satisfied than nonusers. Both groups felt the same degree of intimacy in their current or recent relationships and shared the same range of sexual experiences. But when it came to violent or fetishist porn, the groups diverged. Consumers of these types of pornography appeared to masturbate more frequently, have more sexual partners over the course of their life, and experience slightly less relationship intimacy than their nonviolent porn–viewing counterparts.

Regular pornography use does not seem to encourage sexism, either. In 2007 Alan McKee, a cultural studies expert at the Queensland University of Technology in Australia, designed a questionnaire to assess sexist tendencies. He enclosed his survey in shipments of pornographic material distributed by a mail-order company and also posted it online. Responses from 1,023 pornography users indicated that the amount of pornography the subjects consumed did not predict whether they would hold negative attitudes toward women. The survey respondents who were most sexist were generally older men who voted for a right-wing political party, lived in a rural area and had a lower level of formal education.

But the questionnaire may have missed a key nuance. In a study published in 2004 in the Journal of Psychology & Human Sexuality, researchers at Texas Tech University administered a different survey to male and female college students and found that although consumers of pornography did not display more negative attitudes toward women, they were more likely than other respondents to believe that women should be protected from harm—what the investigators call “benevolent sexism.”

Self-Medicating with Fantasy

Perhaps the most serious accusation against pornography is that it incites sexual aggression. But not only do rape statistics suggest otherwise, some experts believe the consumption of pornography may actually reduce the desire to rape by offering a safe, private outlet for deviant sexual desires.

“Rates of rapes and sexual assault in the U.S. are at their lowest levels since the 1960s,” says Christopher J. Ferguson, a professor of psychology and criminal justice at Texas A&M International University. The same goes for other countries: as access to pornography grew in once restrictive Japan, China and Denmark in the past 40 years, rape statistics plummeted. Within the U.S., the states with the least Internet access between 1980 and 2000—and therefore the least access to Internet pornography—experienced a 53 percent increase in rape incidence, whereas the states with the most access experienced a 27 percent drop in the number of reported rapes, according to a paper published in 2006 by Anthony D’Amato, a law professor at Northwestern University.

It is important to note that these associations are just that—associations. They do not prove that pornography is the cause of the observed crime reductions. Nevertheless, the trends “just don’t fit with the theory that rape and sexual assault are in part influenced by pornography,” Ferguson explains. “At this point I think we can say the evidence just isn’t there, and it is time to retire this belief.”

What if it turns out that ­pornography use actually reduces the desire to rape? It is a controversial idea, but some studies support it. Work in the 1960s and 1970s reported that sexual criminals tend to be exposed to pornographic materials at a later age than noncriminals. In 1992 Richard Green, a psychiatrist at Imperial College London, disclosed in his book Sexual Science and the Law that patients requesting treatment in clinics for sex offenders commonly say that pornography helps them keep their abnormal sexuality within the confines of their imagination. “Pornography seems to be protective,” Diamond says, perhaps because exposure correlates with lower levels of sexual repression, a potential rape risk factor.

A Personal Concern

Repression seems to figure prominently into the puzzle of pornography. In 2009 Michael P. Twohig, a psychologist at Utah State University, asked 299 undergraduate students whether they considered their pornography consumption problematic; for example, causing intrusive sexual thoughts or difficulty finding like-minded sex partners. Then he assessed the students with an eye to understanding the root causes of their issues.

It turns out that among porn viewers, the amount of porn each subject consumed had nothing to do with his or her mental state. What mattered most, Twohig found, was whether the subjects tried to control their sexual thoughts and desires. The more they tried to clamp down on their urge for sex or porn, the more likely they were to consider their own pornography use a problem. The findings suggest that suppressing the desire to view pornography, for example, for moral or religious reasons, might actually strengthen the urge for it and exacerbate sexual problems. It’s all about “personal views and personal values,” Twohig says. In other words, the effects of pornography—positive or negative—have little to do with the medium itself and everything to do with the person viewing it.