Dr. Fisher and I have somewhat different views on what the overall literature indicates, and I'd like to just comment briefly on the two aspects he talked about.
In his study where it's said said they control for sex drive and the effects of pornography then disappeared, there is a serious confound wherein one of the key elements of how they define sex drive is how often you masturbate. A very large percentage of those masturbatory activities occur during the use of pornography. Consequently, of course, once you tease out that particular contribution, the effects of pornography or the role of pornography is going to disappear once we have separated those two in a semi- [Inaudible—Editor] writing up of the results, and indeed, pornography continues to have an impact.
Plus, I should point out that the conclusions I have stated are not based on any single study, and there are now a large number of meta-analyses that look across the different methodologies that have existed and summarize all the relevant studies and interview methodologies and dozens and dozens of studies that point to the same conclusion. Not only that, but it turns out that Dr. Fisher in his own writing—and I'd be glad to give you a citation—some years ago has argued for the conclusions that I presented that certain individuals are more anti-social; tendencies may indeed be affected, while the majority of people who are not may not be affected.
Second, Dr. Fisher refers to what we call aggregate studies, and as he noted, there's caution where you can say, well, at the societal level, there may have been an increase in pornography use, but there doesn't seem to be a corresponding increase in sex crimes and so forth.
Aggregate studies have a lot of problems, and this is well known, because there are many other changes occurring in the society at the same time. For example, it is probably the case that in the last 10 years, the number of guns in the United States has increased exponentially—I have data to show that—yet the rates of crime have actually decreased quite a bit, as everyone knows and nobody seems to have a good explanation for it. Does that mean that more guns are actually associated with less violence and in fact we can say that there might be some causes or that having more guns has not contributed to more violence? I think that would be a very precarious type of conclusion.
And no one is arguing, as I said, that pornography is a primary cause and that you can expect, with the gradual change in the availability of pornography, there to be some dramatic increase in levels of sexual assault. Indeed, sexual assault that's known to the police or that is adjudicated is generally committed more by what we call generalists: anti-social individuals who will commit a wide variety of acts that are illegal/anti-social and who are not necessarily specifically, sexually criminals.
In the case of the populations we've studied, men in the general population, they tend to be more specialists. And for them, as I emphasize, the data showed that, for the majority of men, pornography exposure does not really have any impact on their aggressive attitudes or their sexually aggressive tendencies or behaviour. But for an important subgroup, those who already have relatively high risk, this is a group for whom—as I said, consistent with Dr. Fisher's earlier writings and our own confluence model—the data, I think, are very clear that indeed exposure to certain kinds of pornography can increase their risk further.
To answer your question, coming back to the issue of of incidental exposure, as I said, I'm not aware of the publication of any actual studies on this. There were certainly many people who report this, and I could give you some of the anecdotal things that have been related to me by some colleagues and other people I have come in contact with.