By Justin Lehmiller

Popular media articles often talk about pornography as if it has effects similar to those of drugs. Among other things, they claim that consumers build up a tolerance to porn over time, meaning that they eventually need to seek out increasingly extreme content in order to become aroused and/or to reach orgasm.

Researchers have dubbed this idea the content progression thesis and is has been discussed in the scientific literature for more than thirty years. During that time, a few small studies have emerged that have provided support for it. However, all of those studies have suffered from the same limitation: people were only surveyed once and they were asked to report on how their pornography use had changed over time. Studies like this are subject to memory and recall biases, and they don’t allow us to make any inferences about cause and effect.

A new study published in the journal Social Science Research aimed to address these limitations by using a longitudinal research design. With this kind of design, researchers were able to document potential changes in patterns of porn use as they unfolded.

Scientists from the University of Zagreb in Croatia surveyed 248 male high school students about their frequency of pornography use and porn preferences at five different periods in time, each separated by about six months.

Participants were age 16 on average when the study began and they completed each phase of the survey online. The main questions of interest focused on how often they used porn in the past six months, as well as the extent to which they had a preference for porn with violent or sexually coercive content. Violent and coercive content were the focus here because that’s really where the main concern has been with the content progression thesis—that porn consumption increasingly produces demand for violent content and makes sexual violence more mainstream.

So what did they find? First, pornography use in general remained pretty stable over the course of the study, with only a very slight trend toward more usage over time.

Second, and inconsistent with the content progression thesis, reported preferences for extreme content actually decreased with time. Specifically, whereas 8.1% of participants reported a preference for violent/coercive porn at the beginning of the study (the highest point), this had dropped to 4.6% by the fourth data collection period (the lowest point).

The researchers also found that those who consumed porn more frequently at the beginning of the study showed a less marked decline in their preference for extreme content. This finding is neither consistent nor inconsistent with the content progression thesis, and the study authors believe that it simply reflects the fact that people who use porn more often tend to have more diverse interests and seek out a wider range of pornographic content.

Although this study is important because it is the first to test the content progression thesis with a longitudinal research design, it does have its limitations. For example, limitations include the fact that only young men were surveyed, the study lasted just two years, and researchers only inquired about violent/coercive porn. It would therefore be useful for future studies to examine potential effects in women, as well as to look for changes over a longer period of time and consider preferences for a wider range of “extreme” content.

With all of that said, these results challenge the popular view that porn consumers necessarily build up a tolerance over time that encourages them to seek out increasingly violent content. These findings also represent a challenge to the popular porn-as-a-drug analogy because “tolerance” doesn’t seem to be one of the hallmarks of the way that porn affects consumers.   

Reference: Landripet, I., Buško, V., & Štulhofer, A. (2019). Testing the content progression thesis: A longitudinal assessment of pornography use and preference for coercive and violent content among male adolescents. Social Science Research.

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Dr. Justin Lehmiller is an award winning educator and a prolific researcher and scholar. In addition to publishing articles in some of the leading journals on sex and relationships, he has written two textbooks and produces the popular blog Sex & Psychology. Dr. Lehmiller’s research addresses topics including casual sex, sexual fantasy, sexual health, and friends with benefits. His latest book is Tell Me What You Want: The Science of Sexual Desire and How It Can Help You Improve Your Sex Life. Follow him on Twitter @JustinLehmiller or facebook.com/psychologyofsex.