You've heard it time and time again: Women do not like to look at porn.
The explanations are varied. Women are not as interested in sex as men are, so sexual images simply are not necessary. Men are more visual when it comes to sexual stimuli and appreciate that extra stimulation in ways that women can't. Mainstream pornography is created by men for men -- and doesn't involve enough emotional content to keep the attention of women. I could go on and on. But you get the picture. There's a pervasive notion that women simply do not like porn. But does neuroscience back that up?
When I looked into this very question as I researched This Is Your Brain on Sex: The Science Behind the Search for Love, the answer, surprisingly, turned out to be "not exactly." Porn has more sway over women's brains than one might think.
Let me back up a bit. Sexual images are special -- especially when we're talking about the brain. Thomas James, a neuroscientist at Indiana University who works with researchers at the Kinsey Institute for Research in Sex, Gender, and Reproduction, told me, "When we put people in [the functional magnetic resonance imaging (fMRI) scanner] and show them sexual stimuli, the response in the brain is two to three times stronger than any other kind of image or stimulus I've ever used." Sexual photos are incredibly arousing. And even if they aren't titillating enough to result in an erection or increased vaginal lubrication, you can see porn's effect in the way the brain lights up in response to it. Our brains, it would seem, are fine-tuned for porn -- and this tell-tale brain activation response happens in both men and women.
That's not to say that there aren't differences. Kim Wallen, a researcher at Emory University, found that men showed greater activation in the left amygdala, the area of the brain responsible for attaching salience and context to the outside environment, when viewing porn. There was also heightened arousal in the hypothalamus, the seat of base sexuality, and in the brain's emotional centers. Wallen argues that these differences in activation may make an argument for the idea that men find sexual images more compelling than women do. Yet, when Wallen and his colleagues asked study participants about how arousing the images were, the women, overall, rated them as more sexually arousing than the guys did. Interesting, no?
More brain activation in men, higher arousal ratings in women -- it presents a bit of a conundrum. It's possible that the general neural circuitry underlying sexual arousal is fairly similar in men and women but those circuits may be differentially activated on the type of stimulus presented. Visuals may kick it up a notch in one area, while touch or sound hold more sway in another. But Wallen and colleagues wondered if something else might be in play here: perhaps men and women were looking at different elements of the pornographic images. If so, that could account for the differences in brain activation patterns.
In a follow-up study, Wallen and co. had study participants view hundreds of sexual photos from free porn websites as their brains were being scanned -- and as their eye movements were being tracked. As they checked out each image, participants were asked to rate how arousing the image was on a scale of 0 to 4. The researchers then took a closer look at what images the participants found arousing, which bits of the image they were actually looking at and where blood was flowing in the brain.
Interestingly enough, there was no difference in the way that men and women rated the different stimuli -- or even how long they checked them out before making a decision on how hot they were. That's right: not only did women find the stimuli just as arousing as the dudes, they also looked at them for the same amount of time. So much for the idea that women aren't built to appreciate sexual images. They managed to keep up just fine.
But, as it so happens, men and women did look at different aspects of the images -- and they rated different types of images as more or less arousing. Women seemed to appreciate photos in which female actors were looking away from the camera. (Note: men did not seem to care which way the female actors were looking.) Neither men nor women seemed to spend much time looking at genital close-up shots -- but men rated them as much less attractive than women did. So, overall men and women showed lots of brain activation. They looked at the images and found them arousing. They just focused on some different attributes while they did so.
What's the take-home here? As in most other lines of scientific enquiry, context matters. A lot. It would seem that women aren't any less affected by porn than men are -- they may just appreciate different aspects of it. But perhaps, more importantly, the take-home message is, when it comes to matters of sex and love, advances in neuroscience are affording us new opportunities to explore (and challenge) some of our most stable sexual stereotypes -- something that can only help us better understand the true nature of human sexuality.