Women’s pain often underestimated

Sex bias appears to affect others’ pain, with a general tendency to underestimate the pain experienced by women, a recent study has found.

The present study consisted of two experiments. The first enrolled 50 lay perceivers who were shown facial video clips of men and women suffering from chronic shoulder pain, and were then asked to score what they thought the pain intensity was according to a 100-point visual analogue scale (VAS). The second experiment sought to validate the findings of the first in a larger sample (n=200).

Prior to controlling facial expressiveness and self-reported pain, no between-sex differences were found in terms of pain as estimated by the lay viewers. However, after adjusting for these factors, women were perceived to be in less pain than men (p<0.001), despite them showing the same level of expressiveness as men.

Such bias was unrelated to the sex of the lay perceiver (p=0.85). On average, there was a 2.23-point VAS score difference between sexes, with an overestimation of pain that men felt.

These findings were confirmed in experiment 2, where women were perceived by the viewers to be in significantly less pain than men even before controlling for confounders (p=0.001). This effect remained significant even after adjusting for self-reported pain and expressiveness (p<0.001), and was unrelated to the viewer’s sex (p=0.76).

Moreover, experiment 2 additionally found that gender bias also affects treatment recommendations: perceivers tended to think that women would benefit more from psychotherapy, while men would benefit more from pain medications.

“These findings suggest that gender biases in pain estimation may be an obstacle to effective pain care, and that experimental approaches to characterizing biases, such as the one we tested here, could inform the development of interventions to reduce such biases,” the researchers said.