Last month, two German scientists published a brain imaging paper in a medical journal that posited a correlation between men who watched a lot of porn and a shrunken area of the brain. Not surprisingly, this study was a big hit with anyone wanting to write a “porn shrinks your brain!” piece, as well as publications like the Christian Post and anti-porn groups like Morality in Media, who took the opportunity to put out a press release, hailing the results “as further proof that porn is harmful to its consumers.”
In a shocking turn of events, it turns out porn proooobably doesn’t shrink your brain, and that all the study really did was suggest a correlation. From Wired:
Here’s what’s caused all the fuss. The researchers found that hours spent watching porn was negatively correlated with the amount of grey matter in a subcortical region near the front of the brain – the right striatum – that’s known to be involved in the processing of reward (as well as lots of other things). In other words, men who said they spent more time watching porn tended to have a smaller amount of grey matter in this part of their brain. Also, the more avid porn viewers showed less activation in their left striatum when they looked at racy images, and they appeared to have reduced connectivity between their right striatum and their left dorsolateral prefrontal cortex.
There’s a lot of poindexter words in that, but basically, they found that men with smaller reward centers watched more porn (or said they watched more porn, anyway). From that, you could extrapolate that either watching more porn shrinks your reward center, OR, men with a smaller reward center need more porn to be rewarded. I’ll leave it up to you to decide which is the more logical conclusion, while I finish ironing “REWARD CENTER” onto the front of these hot pants.
A further problem with correlational studies is not just that the causal direction can run either way, but that an unknown or uncontrolled third factor (and others) could be causally involved. In the case of this study, the elephant in the room is personality. Unsurprisingly, personality is linked with media use (including porn consumption) and with brain characteristics. Asking men how much porn they watch is a crude indicator of their extraversion, (lower) conscientiousness and desire for sensation seeking. For instance, men who watch porn in work hours tend to be less conscientious and more impulsive. Last year, a study reported: “Neuroticism, agreeableness, conscientiousness, and obsessional checking all significantly correlated with a latent measure of compulsive behavior upon which use of Internet pornography use also loaded.”
“Elephant in the Room” is my favorite porn, because your mom was in it. Haha, I’m an adult.
By failing to measure or control for personality, the results of this study are virtually meaningless. The men’s self-reported time spent watching porn is little more than a rough proxy for their personality profile, including their willingness to diverge details about their private habits. And we already know that key personality traits such as extraversion and sensation seeking are linked with distinct patterns of brain structure and response. By failing to follow up participants over time, the research also provides no evidence that watching porn has any effects whatsoever. Moreover, by also neglecting to measure any other media consumption, then even if before/after evidence were available, we wouldn’t know if it were due to porn consumption or to other media activities correlated with that porn use, such as watching violent movies and online gambling (to be fair, the findings did still hold after the researchers controlled for overall levels of internet use). […] This study does not make a helpful contribution. Suggested new headline: “Watching moderate amounts of porn won’t hurt your brain”. [Wired]
Like it matters. If watching porn actually did shrink your brain, do you think people would stop doing it? Of course not. People didn’t stop masturbating when masturbation causing blindness was accepted scientific fact. They just figured “f*ck it, I’ll jack† off to braille.”
How do I know they didn’t stop masturbating? Well, because I have pictures. Of your mom.
†Or jill