People will often go to great length to convince themselves that their vices are actually virtues or, short of that, at least that their vices are somehow a bulwark against worse vices. Sometimes pseudoscience is utilized to lend an empirical veneer to this self-justication. Someone recently sent me a link to a Scientific American article from last summer which attempts to make the case that porn is actually good for society:
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.
Obviously, even if there is a social correlation between porn availability and decreased rates of rape, this doesn’t mean that use or creation of porn is moral. Lots of highly immoral activities may happen to correlate with (or even cause) decreases in other immoral activities, and the fact that one of these is immoral doesn’t change the immoral status of the other.
However, the whole set of claims sounded fishy to me. “Lowest levels since the 1960s” seems like one of those statement which might, while technically true, still mask a huge difference, rather like “worst economic downturn since the Great Depression”. Similarly, measuring statistics based on “the states with the least Internet access between 1980 and 2000—and therefore the least access to Internet pornography” seemed incredibly vague. The internet wasn’t even particularly useful for pornography before the advent of the World Wide Web in the early ’90s, so the 1980 to 2000 time frame intentionally included a lot of irrelevant time, and measuring the states with the least internet access was likely to simply get you the poorest and most rural states.
Further, I just found the whole proposed causal mechanism doubtful. It sounded like the sort of thing where someone fished for a some correlations that worked just a little bit, but they were probably really just seeing some wider trend. My going hypothesis was the the rate of rape would mirror the rate of other violent crimes such as murder. If the rate of rape deviated from the rate of other violent crimes a lot, it would suggest that rape had different causal mechanisms that other forms of violent crime. If it rose and fell in a similar pattern (and I knew that violent crime as a whole had been falling since peaking in the early ’90s) that would suggest that rape was just another, particularly nasty, form of social violence.
Searching around, I found two major sources of crime statistics that track the incidence of rape in the population as a whole. The first of these is the Uniform Crime Reporting Statistics database maintained by the FBI. This database is compiled from local law enforcement agencies by the FBI and statistically adjusted to make up for missing, over-reported or under-reported data. From there I was able to pull data on the rate per 100,000 of population of the set of violent crimes the database tracks: murder, aggravated assault, forcible rape, and robbery. The some total of these is the Violent Crime Rate. The following chart shows those four constituent rates since 1960.
As you can see, the pattern match is very strong. The lowest correlation is between murder and rape, a 54% correlation. Robbery has a 84% correlation and aggravated assault has a 96% correlation. The overall violent crime rate has a 97% correlation with the rate of forcible rape. With correlations that high, if you ask me to tell you what the rate of rape is in the US in any given year, I’m not going to ask you, “Gee, how available was porn that year?” No, I’ll ask you, “What was the overall rate of violent crime?” That is a far, far more predictive indicator than anything vague association with porn availability. And predictability is what science is all about. All the rest of what we’re hearing is hand waving and self justification.
I then ran averages for each decade. In the 1960s the rape rate was 12.3 per 100,000 of population.
In the 1970s, 26.0.
In the 1980s, 36.5.
In the 1990s, 38.3.
In the 2000s, 32.2.
So Prof. Ferguson’s statement is actually false, the rape rate is not at its lowest since the 1960s (it was lower in the ’70s than it was in 2010 at 27.5) and the current rape rate is more than 2x the rate for the 1960s, when pornography was unquestionably much less available than now. The only way that this pseudo correlation comes to be is that the web has only existed since the early ’90s and by coincidence all forms of violent crime have been on a steady decline since the early ’90s. Unless one wants to claim that burglary and aggravated assault rates are being driven down by the availability of internet porn, we don’t have much of a causal case to make here.
There’s a second major source of government data on violent crime called the National Crime Victimization Survey. Whereas the UCR data is based on crimes reported to law enforcement, the NCVS is compiled by the justice department by contacting 40,000 randomly selected households annually and asking all the members of those households who are over twelve years old about any crimes which they have personally been victims of during the last year. The idea behind using this methodology is that some people may not report crimes they suffer to the police. Since rape victims in particular are often afraid to come forward to authorities (whether because they fear retaliation from the rapist or out of shame) many sociologists believe that the NCVS provides a truer view of the incidence of rape in society.
I obtained the NCVS data (which unfortunately only goes back to 1973) and analyzed that as well. This source shows a much higher incidence of rape (and of other violent crimes) than the UCR data, and the shape of the trend is different: it shows a steady decline in all crime categories since the early seventies. However, the correlation between rape and other violent crimes is similar to in the UCR data.
Running the correlation between the sets of annual data for rape and total violent crime, I get a correlation of 89%. There’s also a correlation of 91% between robbery and rape and of 91% between aggravated assault and rape. Simple assault shows a correlation of 82% with rape.
This means both that the rate of decline in the rape rate, as shown in the NCVS’s survey methodology is not unprecedented, and that one can predict the number of rapes likely to have occurred in a year with a fair degree of accuracy by knowing the amount of overall violent crime. The availability of pornography does not have this predictive value — or at least, none of these “studies” which attempt to show a connection between the availability of porn and the number of rapes even attempts to put together some sort of annual number which can be used to measure porn consumption or availability, and so any attempt at prediction is impossible.
Really the only thing that the porn-reduces-rape thesis has going for it, according to the NCVS’s data is that the incidence of rape took a sharp down turn in 1991 which was three years before the overall violent crime rate took a sharp downturn in 1994. However, since that time the rape and violent crime as a whole have decreased at almost exactly the same rate. I think it would be virtually impossible to attribute this 1991-1994 divergence in the trends to internet pornography, given how comparatively small the internet was at the time. If internet porn were truly a “safety valve” which prevented men with deviant sexual urges form assaulting real women, we would expect the effect to become more pronounced (for the incidence of rape to decrease much faster than violent crime as a whole) as internet pornography became more prevalent in the last decade.
What we see, I think, in this attempt to associate pornography with a decrease in rape is self-justifying behavior. In a society in which far too many men satisfy their sexual urges alone by watching the exploitation and objectification of women in pornography, those who make this claim are attempting to deflect attention from the one fault (using pornography) by associating this vice with a decrease in an even worse exploitation and objectification of women: rape.
Strictly looking at the data, rape is simply a form of violence: a particularly exploitative and personal form of violence, and one primarily directed against women, but a form a violence which increases and decreases in society as the overall rate of violence increases and decreases. As such, it is not surprising that crime statistics show the incidence of rape to be highly correlated with those of other violent crimes. However, at the moral level, rape is simply a more extreme form of the desire to use and objectify others which is also at the root of the pornography industry.