The role of pornography in the etiology of sexual aggression Michael C. Seto*, Alexandra Maric, Howard E. Barbaree Centre for Addiction and Mental Health, Toronto, Ontario, Canada Abstract Despite the public and scientific attention the topic has received, the evidence for a causal link between pornography use and sexual offending remains equivocal. This article critically examines the research literature on the association of pornography and sexual offending, focusing on relevant experimental work. The difficulty of this research is highlighted in a discussion of operational definitions of the term pornography , the choice of proxy measures for sexual offending in experimental research, and the emphasis given sexual assault of adult females over other kinds of criminal sexual behavior such as child molestation, exhibitionism, and voyeurism. We also review the major theoretical perspectivesÐ conditioning, excitation transfer, feminist, and social learningÐand some of the hypotheses that can be derived from them. From the existing evidence, we argue that individuals who are already predisposed to sexually offend are the most likely to show an effect of pornography exposure and are the most likely to show the strongest effects. Men who are not predisposed are unlikely to show an effect; if there actually is an effect, it is likely to be transient because these men would not normally seek violent pornography. Finally, we present a Darwinian perspective on the possible relationship between pornography use and sexual aggression. D 2000 Elsevier Science Ltd. All rights reserved. Keywords: Pornography; Etiology; Sexual aggression 1. Introduction 1.1. Extent of the problem Since the first large-scale public inquiry into pornography by the U.S. Commission on Obscenity and Pornography (1970), there has been vociferous debate about the potentially * Correspondence should be addressed to Michael Seto, Law and Mental Health Program, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, Canada M5T 1R8. E-mail address: michael seto@camh.net (M.C. Seto). _ 1359-1789/01/$ ± see front matter D 2000 Elsevier Science Ltd. All rights reserved. PII:S1359-1789(99)00007-5 Aggression and Violent Behavior 6 (2001) 35±53