We thank Drs. Kingston and Malamuth for their interest in our article and comments on the methodology used in our study. There are considerations with which we agree and others with which we take issue.
As we interpret their comments they don’t argue with our aggregate findings. They do, however, caution that it is often wrong to extrapolate from aggregate population data to individual behavior. And they offer several examples from the literature where that has been demonstrated. We agree that there is a risk in connecting disparate measures of behavior and a problem with making assumptions of individual behavior based only on aggregate data. However, Kingston and Malamuth have not shown that we have made such an erroneous connection within our findings so they are talking in generalities.
Actually, we did analyze our data to avoid possible bias caused by aggregation. To increase clarity in our original article, however, that analysis was not mentioned. Along with the data reported we also obtained data on convicted offenders from the official Yearbooks of the Ministry of Justice in the Czech Republic, for the years 1979-2007. We analyzed the number of child sex abuse offenders and rape offenders for the period when sexually explicit materials (SEM) were unavailable (the time before the 1989 revolution) and compared these figures with the number of offenders recorded for the interval when it was available. There were significantly fewer child abuse and rape offenders during the period of porn availability (P <0.001) (Diamond, Jozifkova, Weiss, in preparation).
Our basic findings were that the significant increase in the availability of pornography in the Czech Republic had resulted in a significant reduction in all manner of sex crime as well as number of sex offenders while, in contrast, the same society experienced a dramatic increase in other social crimes such as robbery and murder with a commensurate increase in the number of criminals convicted for such crimes.
Kingston and Malamuth stressed the existence of the link between pornography and both sexual and nonsexual aggression as mentioned by Allen, D’Alessio and Brezgel (Allen et al., 1995). Since all of the data we presented, about both sex and non-sex crimes, were collected the same way we don’t think there was any bias in our data acquisition. If SEM did increase criminal aggressiveness that should have been reflected by an increased number of sexually aggressive assaults and sex related murders. Neither was seen.
With our data, combined with the knowledge that, in every other country where it had been scientifically studied, from Japan, Hong Kong and China to Denmark, Germany and Sweden, to Croatia, the Czech Republic, the U.S., Canada, and the U.K. (Diamond & Uchiyama, 1999, Diamond, 2009, Diamond, 2010, Kutchinsky, 1991, Landripet et al., 2006, Ng, 1994, McKay & Dolff, 1985, Home Office, 1979), an increase in the societies’ availability of pornography was correlated with a decrease in sex crimes, we did hypothesize that sexually explicit materials provided a displacement. And the displacement activity that we hypothesized was masturbation. The law of parsimony led us to propose this as the simplest explanation for what we consider to be a unique similarity in so many different societies. We believe we can safely assume that in all of the societies studied, regarding pornography, masturbation decreases sexual arousal and thus can reduce motivation to engage in sex activity.
And since our study was based on a total population sample over many years, it can be assumed that even those who might have offended at one time were no longer doing so, or the number of offenses would not have decreased. What we do know is that over time the authorities recorded fewer sex related crimes and fewer offenders.
A major disagreement we have with the Kingston and Malamuth critique, and others like it is a starting assumption that aggressive attitudes are inextricably linked to pornography and their implication we should have somehow measured that or at least mentioned it in our paper. We believe that such criticism compares apples with oranges. Potter (Potter, 1996) as well as many others, have found that the main use of sexually explicit materials if for entertainment, relaxation, tension release, education and to sexually enhance a relationship. Neither Kingston and Malamuth or others have demonstrated that changes in aggressive attitudes have resulted in commensurate changes in real-world sexual aggression. In the studies showing increased aggression following attitude testing, there are no follow-up studies showing actual sexual assaults by the subjects that expressed the aggressiveness. Negative or aggressive attitudes are not always followed by antisocial or aggressive behaviors.
Such a link has been often studied with laboratory or school investigations of aggressive attitudes. The accusations of a link abound. But actual demonstration of real-life behavioral aggression caused by pornography has not been found. To support their argument that a link does indeed exist the work of Allen, D'Alessio, and Brezgel (Allen et al., 1995) is cited. These authors, however, themselves say the studies they and others review for their meta-analysis are suspect since the data come from experimental laboratory situations and “this constitutes a systematic [flawed] factor existing across all the investigations (p.275).”
Another major problem with any critique assuming pornography should be linked with aggression and sex crime ignores the reality that sex laws are statutory social distinctions that criminalize even consensual sex and sexual behaviors that are obviously without aggressive features. Indecent exposure, for instance is a sex crime in the Czech Republic as it is in the U.S. and consensual sex between an 19 year old and a 14 year old would be sex crimes in both countries. Neither activity involves aggression. Sexting also may be recorded as a sex crime if a minor is involved.
We certainly agree with Kingston and Malamuth that it would be of value to better understand the role of individual responsiveness to pornography consumption. We can also accept the potential that some individuals might be somehow increasingly motivated to be aggressive following exposure to porn and it would be of value to know how to predict who such persons might be and what might be the triggers to their antisocial behaviors. And the debate is still open as to whether deviant or aggressive pornography would, or would not, in the real world, have a cathartic effect. We will leave these determinations to others.
There are two last comments in regard to the Kingston and Malamuth critique. We think several of the examples they used in discussing sexual crimes are erroneous. Robinson (Robinson, 1950) discusses links between illiteracy and immigrant status. Subramanium, Jones, Kaddour, and Krieger (Subramanian et al., 2009) discuss illiteracy and Jim-Crow segregation laws. These articles discuss nothing regarding pornography and we see them shedding no light on our discussion.
Last, Kingston and Malamuth state that antisocial behaviors are “over-determined.” By this they mean, “There are two or more sufficient and distinct causes for the same effect.” And they fault us for not looking for a multitude of factors that might be involved in this over-determination. We are happy to leave investigation of any such possible relations to others. What we were seeking to investigate is the often-expressed belief that an increase in the availability of pornography would lead to an increase in sex crime. We, as every one else who has studied the matter, have found that to be a myth. We are content to leave finding the reason for this to others.