We believe that people who can handle pain are more formidable

In the popular imagination, the ability to withstand physical pain is often linked to particular attributes. Getting tattooed or pushing yourself at the gym, for example, is often seen as an indicator that someone is strong minded and determined.

Now a study in Evolution and Human Behavior has found that we also believe that people who are insensitive to pain are physically more formidable – and vice versa.

In the first study, participants read one of two short passages which portrayed a man who was either sensitive to pain, or not. After reading the vignette, participants indicated how big and muscular they felt the person would be by selecting from various silhouettes and estimating their height. They also indicated the extent to which they felt the man was financially successful, influential, aggressive and risk-taking.

Participants felt that those who were insensitive to pain were more likely to be muscular, large, and tall. They also believed them to be higher in social status, more aggressive, and more likely to engage in risky behaviours. Interestingly, the link between insensitivity to pain and physical formidability still held even after taking into account these latter effects. A second study replicated these findings.

So we see people who are insensitive to pain as more formidable. But what about the reverse: do we also think that potentially dangerous people are less sensitive to pain? To explore this, in the final study participants either saw various men holding non-threatening implements (a spatula and a watering can), or tools that could be used violently (garden shears and a kitchen knife). They then estimated how much pain each man would experience in a variety of contexts such as getting their fingers caught in a car door, and indicated how much the man was feeling angry, grossed out, and scared when the photo was taken.

Participants believed that the men holding potential weapons were less sensitive to pain than those holding non-weapon objects. They were also seen as angrier, though there was no impact on disgust or fear.

Overall, the results suggest that we link formidability with lack of sensitivity to pain. And this may have serious repercussions. Racist stereotypes that Black people are more aggressive than White people is already known to be a factor in law enforcement's discriminatory approach to policing people of colour. There are also widespread false beliefs about racial differences in the experience of pain: for example, studies have shown that many medical staff wrongly believe that Black women are less sensitive to pain than White women. So if people believe that those who are less sensitive to pain are also more aggressive and formidable, it's easy to see how these two stereotypes could reinforce each other, with potentially deadly results.