Facial expressions of pain and orgasm are different, according to a study published this week (October 8) in PNAS. Forty Western and 40 East Asian participants viewed computerized images of a human face and categorized the expressions as indicative of pain, orgasm, or other. For pain and orgasm, participants also rated the intensities of the expressions they viewed.
In contrast to previous research that suggested expressions of pain and orgasm are “virtually indistinguishable,” according to the PNAS paper, the new study found that there were distinctions between the two—namely, expressions of pain involve pulling the face inward (lowering the eyebrows and wrinkling the nose, for example) and expressions of pleasure involve movements that expanded the face, such as raising the eye brows. Moreover, while Western and East Asian observers viewed expressions of pain similarly, there were culture-specific elements of orgasmic expressions. For example, Westerners’ o-face involved wide-open eyes and a dropped jaw, while East Asians’ expression involved smiling.
C. Chen et al., “Distinct facial expressions represent pain and pleasure across cultures,” PNAS, doi:10.1073/pnas.1807862115, 2018.