Through the years, scientific studies have been used by individuals, institutions and governments to support positions on both sides of sex war debates on pornography. Studies have produced seemingly opposite conclusions at times giving each camp ammunition for their own side, and leaving the curious individual to wonder if they can really be used to draw any conclusive evidence about pornography at all.
How to Use a Study:
The first reason for the problem we have in conflicting studies, is because of the tendency to take a study out of its context and draw more conclusions from the results of a study than we are really able to. Epidemiological studies often study the effect of something on a population, but stress that assigning the root cause is a very complicated matter. Over-simplifying the results of a study by making simple one cause-one effect conclusions is an error of logic. But, sadly this is the way that many sides approach studies in an effort to support their arguments. Often, many more follow up studies are needed to determine the actual cause of the result in a study, or to rule out and consider other factors present. For example: "The Effects of Pornography: An International Perspective" was a large study that found that the rate of sex crimes dropped with the legalization of pornography. This influenced the legislation of some governments who then believed that pornography was not having a negative effect on their populations, but this has been critiqued as an error of logic and misuse of the study because other factors were also present at the same time that significantly contributed to a reduction in sexual crime, such as increased targeting by law enforcement. These other factors were not accounted for in the study, and no follow up was done to determine the specific cause and effect relationship.
Not All Studies Are Equal:
The second problem with the use of studies is the assumption that you can compare their results equally. Each study approaches its experiment or question in a particular way. With the question of pornography and violence, scientists have a number of factors to contend with when framing a study.
One: A situation in a lab is very different from a real life experience, so how do scientists get data that will most accurately translate to real life? Experiments vary in their ability to accurately assess real life data.
Two: Because of the nature of the study, (exposing men to varying degrees of sexual content and violence, and then measuring their aggression towards women, and measuring their change in arousal patterns) there are ethical concerns in what the men are exposed to, how to test their aggression to women, and the inability to test on adolescent youth who might be most responsive. These ethical issues inform the studies and limit the studies at the same time from getting the most accurate information. It takes careful thought and creativity to address these issues.
Three: The number of variables accounted for in a study is an indicator of the quality of the study. As shown earlier, the more cause and effect factors you are able to account for the more accuracy you are likely to have. Many of the differences between results in studies on pornography are simply a difference in number of variables. For example: A study linking pornography use to violence will result in high numbers if the sample population is taken from a group of prison inmates. Where as, a group of middleclass white college students might result in a low link between pornography and violence. The study in each case would be flawed and highly unreliable in its ability to give us a true picture of the effect of pornography because of the low number of variables.
Meta-Analysis is a useful method that combines multiple studies and compares data using statistical analysis to give us a more accurate picture of study results than any one study could give us by itself. Once again, not all studies are equal, so which studies you use are important, but if you put in balanced studies with multiple variables, then you will get the most accurate data from the combined results of all the studies put together.
I read the results of a meta-analysis by N.M. Malamuth, T. Addison, and M. Koss looking at the results of 16 experiments on pornography and sexual aggression. They were especially concerned with this issue of inaccuracy in interpreting and conducting studies, and they wanted to know if there really is any hard proof one way or the other on pornography. Their article is called "Pornography and Sexual Aggression: Are There Reliable Effects and Can We Understand Them?"
(Warning: this link is to download the pdf, and this is a long dense article, but it is wonderful material).
There was too much material to include in this blog entry, but I will summarize some of the results of their meta-analysis. First of all, they found over 50 variables that were likely to contribute towards sexual aggression, coercion and violence against women. Pornography (whether it was soft, hard, rape/violent) by itself was the largest single variable contributing towards aggression against women (12%), but this could increase depending on the factor it was combined with: delinquency, sexual promiscuity, child abuse, social isolation, group dynamics etc. Each man has many factors influencing him and some of those combine to result in aggression towards women, while other men who use pornography while having a 12% increase in their likelihood of aggression towards women, never actually display this behavior because they do not have enough other contributing factors. Interestingly, nudity was found to be distinct from pornography, and had the effect of lowering aggression.