Are youths that watch violent X-rated material 6 times more likely to force others sexually?

Question

Internet Safety 101 reports:

Youth who look at violent x-rated material are six times more likely to report forcing someone to do something sexual online or in-person versus youth not exposed to x-rated material.

Obviously correlation does not equate to causation, but I find this hard to believe. Can this claim be justified?

Many of the highly suspect claims on this site correlating pornography to poor behavior use ill-defined terms which make evaluating their accuracy difficult. For the sake of this question, let's give them the benefit of the doubt by interpreting any ambiguous claim generously. For instance, I would say that "violent x-rated material" should be interpreted as pornography with themes of violence, rape, S&M, or harm to another (on the presumption that would make the claim more likely to be accurate), and that "youths who look at" would mean youths who regularly view this material, rather than viewing it only once.

Answer 1

Following the references, it appears that the factoid derives from the following study:

• Michele L. Ybarra, Kimberly J. Mitchell, Merle Hamburger, Marie Diener-West, and Philip J. Leaf, X-Rated Material and Perpetration of Sexually Aggressive Behavior Among Children and Adolescents: Is There a Link?, AGGRESSIVE BEHAVIOR, Volume 37, pages 1–18 (2011)

In this study they followed over 1,000 representative US youths (initially 10-15 year olds, male and female) for 36 months, and asked them three times about whether and how they watched x-rated material and whether they had partaken in sexually aggressive behaviour.

Sexually aggressive behaviour spanned a wide range, including down to unwanted kissing, unwanted sex-related text messages or pictures, or trying to get others to talk about sex when they didn't want to.

After compensating for some confounding factors, such as substance abuse or being victims of sexual aggression, they found:

intentional exposure to violent x-rated material over time predicted an almost 6-fold increase in the odds of self-reported sexually aggressive behavior [...] whereas exposure to nonviolent x-rated material was not statistically significantly related

A single study is, by itself, insufficient evidence. There may be other confounding variables that the authors did not consider. The authors are careful in their conclusion to note the limited strength of the finding.

Our findings need to be replicated. Nonetheless, the data suggest that further examination of associations between sexually aggressive behavior and consumption of violent x-rated material among children and adolescents is warranted.

In short, the factoid is based on genuine science, but drawing a firm conclusion would require further evidence.

Two minor points: (1) The study found the Odds Ratio (OR) was 5.8, not 6, as reported in the snippet. (2) After reading the author list I really wanted to meet the researcher with the spectacular name Merle Hamburger. Alas, he passed away in 2011.