In this older post I mentioned the possibility that pornography causes sexual violence, and that this violence could be one of the justifications for prohibiting or limiting pornography, and hence for limiting one form of free speech. (The physical integrity rights of the victims of pornography induced sexual violence outweigh the rights to free speech of pornographers and their clients). I also cited some scientific research corroborating the link between pornography and sexual violence.
Now I came across some evidence pointing in another direction. Large increases of internet use of the last years, together with a proliferation of websites offering free porn, should, in theory, lead to a large increase in the numbers of rape. But that isn’t the case.
The rise of the Internet offers a gigantic natural experiment. Better yet, because Internet usage caught on at different times in different states, it offers 50 natural experiments. The bottom line on these experiments is, “More Net access, less rape.” A 10 percent increase in Net access yields about a 7.3 percent decrease in reported rapes. States that adopted the Internet quickly saw the biggest declines. And, according to Clemson professor Todd Kendall, the effects remain even after you control for all of the obvious confounding variables, such as alcohol consumption, police presence, poverty and unemployment rates, population density, and so forth. Steven E. Landsburg (source)
A vocal segment of the population has serious concerns about the effect of pornography in society and challenges its public use and acceptance. This manuscript reviews the major issues associated with the availability of sexually explicit material. It has been found everywhere it was scientifically investigated that as pornography has increased in availability, sex crimes have either decreased or not increased. (source, source)
So it seems that the opposite is true: more porn = less rape. Maybe porn is a substitute for rape. In which case, one of the justifications for restricting the free speech rights of pornographers collapses. However, I mentioned in my old post that sexual violence isn’t the only possible reason to limit the rights to free speech of pornographers. Pornography can, for instance, perpetuate discriminatory gender roles. And the quote below shows that there is some evidence that pornography increases the likelihood of re-offending:
In this study, we examined the unique contribution of pornography consumption to the longitudinal prediction of criminal recidivism in a sample of 341 child molesters. We specifically tested the hypothesis, based on predictions informed by the confluence model of sexual aggression that pornography will be a risk factor for recidivism only for those individuals classified as relatively high risk for re-offending. Pornography use (frequency and type) was assessed through self-report and recidivism was measured using data from a national database from the Royal Canadian Mounted Police. Indices of recidivism, which were assessed up to 15 years after release, included an overall criminal recidivism index, as well as subcategories focusing on violent (including sexual) recidivism and sexual recidivism alone. Results for both frequency and type of pornography use were generally consistent with our predictions. Most importantly, after controlling for general and specific risk factors for sexual aggression, pornography added significantly to the prediction of recidivism. Statistical interactions indicated that frequency of pornography use was primarily a risk factor for higher-risk offenders, when compared with lower-risk offenders, and that content of pornography (i.e., pornography containing deviant content) was a risk factor for all groups. The importance of conceptualizing particular risk factors (e.g., pornography), within the context of other individual characteristics is discussed. (source)