The Body · Level 1

Your Brain on Porn

Gary Wilson · 2014

Thesis

Internet pornography, with its endless novelty and intensity, is a supernormal stimulus that can overwhelm the brain's reward system and produce changes similar to those seen in addiction, including escalating use and sexual problems, and many heavy users recover by stopping altogether.

Strength of evidence: contested. Some brain-imaging studies find differences in heavy users, but they are small and correlational; major diagnostic manuals do not recognize pornography addiction as such, and researchers remain divided.

The main ideas

• Internet pornography differs from earlier forms because it offers unlimited novelty at the click of a mouse.
• It acts as a supernormal stimulus, an exaggerated version of a natural reward that can outcompete the real thing.
• The brain's dopamine-driven reward system, evolved to pursue novelty, can be pushed into patterns resembling addiction.
• Heavy users, Wilson argues, may need more extreme material to feel the same arousal.
• He links heavy use to sexual problems in young men, including erectile difficulties with real partners.
• Many men report recovering by stopping completely for a period.
• The science is unsettled, and critics argue the addiction model is not supported.

The great porn experiment

Gary Wilson was an American writer who ran a website, yourbrainonporn.com, collecting accounts from men who believed pornography was harming them. In 2012 he gave a talk at TEDxGlasgow called "The Great Porn Experiment," which drew millions of views. The book grew out of it. First published in 2014 and revised in 2017, it was translated widely. Wilson died in 2021.

His central claim is that the internet created an unprecedented experiment. For the first time, a generation of young men had unlimited access to an endless stream of novel sexual material from adolescence onward, and nobody knew what the effects would be.

His evidence draws on neuroscience research on addiction and on the self-reports of men who described problems they attributed to pornography and their improvement after giving it up.

Implication: when a technology changes the supply of a natural reward dramatically, ask whether the brain's responses, evolved for scarcity, still serve the person.

Supernormal stimuli

Wilson builds on the work of the ethologist Niko Tinbergen, who found that animals could be fooled by artificial objects that exaggerated natural cues. Birds would prefer to sit on oversized fake eggs over their own; male butterflies would pursue painted models over real females.

He argues that internet pornography is a supernormal stimulus of this kind. It offers more novelty, more variety and more intensity than any real sexual partner, available at any hour, and so it can capture a reward system evolved to respond to much weaker cues.

The mechanism is that a reward system tuned for natural levels of stimulation responds even more strongly to exaggerated versions, which can make the natural version seem dull.

Implication: be wary of products engineered to exceed the natural rewards our instincts evolved for, since they may displace the real thing.

The reward circuit

The core of Wilson's argument concerns dopamine, a chemical messenger central to motivation and the pursuit of reward. Novelty releases dopamine, and internet pornography offers almost unlimited novelty: a new image or video is always one click away.

Wilson argues that repeated overstimulation can change the brain in ways that resemble substance addiction. Users become less sensitive to ordinary pleasures, more strongly driven by cues associated with pornography, and less able to control their use. In his account, some users escalate to more extreme material to achieve the same effect.

The mechanism, in his view, is that the brain adapts to overstimulation by reducing its responsiveness, so the user needs more to feel the same.

Implication: if a habit requires steadily more intense stimulation to satisfy, treat that as a warning sign, whatever the habit is.

Sexual problems

Wilson's most discussed claim is that heavy pornography use can cause sexual problems in young men, including difficulty becoming aroused or maintaining an erection with a real partner, while remaining able to respond to pornography.

He drew this claim largely from the accounts of men on his website and in online forums, who described such problems and reported that they resolved after they stopped using pornography.

The evidence is disputed. A 2015 study by Landripet and Štulhofer of several large samples of men in Europe found little association between pornography use and erectile or other sexual difficulties, though critics have argued over how its results should be read.

The mechanism Wilson proposes is that the brain conditions sexual arousal to the specific cues of pornography, such as novelty and the screen, which a real partner cannot match.

Implication: if you experience sexual problems and use pornography heavily, a trial period without it is a low-cost test, though it does not replace medical advice.

Rebooting

Wilson's remedy is to stop using pornography completely for a period, which he and many online communities call rebooting. The aim is to let the brain's reward system return to normal sensitivity.

Accounts collected by Wilson describe improvements in mood, motivation, concentration and sexual function, though some men report a difficult period in which libido seems to disappear before it returns.

These accounts come from self-selected men who chose to quit and chose to report their experience, and have not been tested in controlled trials.

The mechanism, in his account, is that removing the supernormal stimulus allows the brain to readjust to ordinary levels of reward.

Implication: when a habit seems to be harming you, a complete break for a set period can show you more about its effects than moderation can.

The scientific dispute

Some research supports parts of Wilson's argument. A 2014 study by Simone Kühn and Jürgen Gallinat found that men who watched more pornography had less gray matter in part of the brain's reward system. Another 2014 study, led by Valerie Voon at Cambridge, found that men with compulsive sexual behavior showed heightened responses to sexual cues in reward-related brain regions that also respond to drug cues in addiction. Both sets of authors cautioned that their studies could not show cause.

Critics reject the addiction model. A 2014 review by David Ley, Nicole Prause and Peter Finn, "The Emperor Has No Clothes," found that most writing on the subject contained no data and argued that heavy use is better explained by high sexual desire and other factors. Research by Joshua Grubbs and colleagues found that people's belief that they are addicted is predicted more strongly by moral or religious disapproval of pornography than by how much they use it.

Neither the American DSM-5 nor the World Health Organization's ICD-11 recognizes pornography addiction as a diagnosis, though ICD-11 includes a broader compulsive sexual behavior disorder.

Implication: treat the addiction framework as one contested hypothesis, and distinguish distress caused by use from distress caused by guilt about it.

Limits

• Its key evidence is weak. The brain studies are small and correlational, and their authors warn against reading them as proof that pornography causes brain changes.
• Its case rests heavily on self-reports. Accounts from men who chose to quit and post about it online are a self-selected sample and cannot show how common the problems are.
• It does not separate harm from guilt. Research on moral incongruence suggests that some people who believe they are addicted are distressed mainly by the conflict between their use and their values.

Related

• The Good Gut — another case that modern environments mismatch systems evolved for scarcity.
• The Art of Seduction — the psychology of desire and the pull of the unattainable.