Popular knowledge and scientific research have perpetuated the belief that the face a person makes when they orgasm is the same one they make when they’re in pain. To social psychologist Jose-Miguel Fernández-Dols, Ph.D., and his colleagues, this seemed like a paradox of the human mind. If one stimulus is painful and the other pleasurable, how could it manifest the same way on the human face? In a new study on o-faces and pain faces in Proceedings of the National Academy of Sciences, they outline their answer to this conundrum.

When they started their research, the Universidad Autónoma de Madrid’s Fernández-Dols and his colleagues didn’t intend on disrupting popular conceptions about the orgasm face. The orgasm itself, he tells Inverse, wasn’t really the point. They wanted to know whether pain and orgasm really did look the same across human faces, and more importantly, they wanted to know why they did or didn’t.

There are studies supporting the idea that the facial expressions produced during pain and orgasm are indistinguishable, but the team’s study refutes that. Going beyond just differences in facial expression, they show that the way people mentally represent — how they think a facial expression should look — an orgasm or painful moment can differ widely. Furthermore, they show that the orgasm face actually varies across cultures.

“The study shows that people have a distinct mental representation of the expression of pain, which seems to have cross-cultural consistency — at least between the two groups being sampled — and a distinct representation of sexual pleasure,” Fernández-Dols says.

Modeling dynamic mental representations of facial expressions of pain and orgasm. Chen et. al.

First, the team created a computerized “face movement generator,” which synthesized a face by randomly selecting a combination of fine face movements, like raising brows, wrinkling the nose, or stretching the lip. Then, a total of 40 observers — half which identified with Western culture and the other half with East Asian — watch 3,600 trials of these faces.

With each wrinkle of the nose and stretch of the lip, the viewers were asked to identify the face as one showing pain, an orgasm, or some “other” experience. Their follow-up task was to describe how closely the face matched their mental representation of the experience: Is it sort of like an orgasm, or is it definitely an orgasm?

While a few participants strained to identify what a face in pain looks like, the group reached a consensus. But when it came to the face of a person experiencing an orgasm, they weren’t as unified: People from Western cultures tended to choose wide-eyed faces with gaping mouths, and people from East Asian cultures chose smiling faces with tightened lips.

Fernández-Dols says only further studies can explain the differences in the mental representations of the o-face, especially because any similarities or differences across cultures could be due to both biological and cultural factors. But for now, he and his team have some hypotheses.

“The expression of pain could have more adaptive relevance than the expression of sexual pleasure,” he says. “On the other hand, the expression of pain could be more visible than the expression of sexual pleasure.”

The meaningful takeaway, Fernández-Dols argues, is that “humans develop solid, consensual mental representations that have a life of their own, with important consequences for human behavior.” The study flies in the face of studies arguing that facial behaviors convey universal emotional messages that all people can understand.

As the differences in o-face mental representation between east Asian and Western cultures show, facial expressions do not have a universal meaning across cultures. It’s possible that some of them could, but for now it seems that an orgasm face might differ, depending on who’s having it — or who’s looking.

Study Abstract:

The distinction between positive and negative emotions is fundamental in emotion models. Intriguingly, neurobiological work suggests shared mechanisms across positive and negative emotions. We tested whether similar overlap occurs in real-life facial expressions. During peak intensities of emotion, positive and negative situations were successfully discriminated from isolated bodies but not faces. Nevertheless, viewers perceived illusory positivity or negativity in the nondiagnostic faces when seen with bodies. To reveal the underlying mechanisms, we created compounds of intense negative faces combined with positive bodies, and vice versa. Perceived affect and mimicry of the faces shifted systematically as a function of their contextual body emotion. These findings challenge standard models of emotion expression and highlight the role of the body in expressing and perceiving emotions.