The Science of Stereotyping

“Our brains want our expectations to be supported,” says Cox. Eric Roman Beining Photography

A new UW study shows why letting stereotypes inform our judgments of unfamiliar people can be such a hard habit to break. It found that stereotypes self-perpetuate in our minds, growing stronger with use.

“Think back to when you were in grade school learning your multiplication tables, and you would repeat them in your mind,” says William Cox MS’08, PhD’15, a UW scientist who studies prejudice. “Going through the world making assumptions about other people with stereotypes we’ve learned is another form of mental practice. With more rehearsal, those assumptions get stronger over time, even when we have no real evidence to back them up.”

Cox, Xizhou Xie ’16, and UW–Madison psychology professor Patricia Devine put more than 1,000 people to work on a stereotyping task that involved reading social media profiles (some of them seeded with stereotypical information) and deciding whether the men in the profiles were gay or straight. Some received feedback about whether they were correct or incorrect, and others received no feedback. Then they read more profiles so researchers could see how the previous feedback affected their answers.

When the feedback mostly confirmed stereotypes, people stereotyped even more over time. Meanwhile, people who received feedback countering stereotypes didn’t seem to learn from it, continuing to stereotype at the same rate. Even more distressing, the people who received no feedback showed learning patterns like the people whose stereotypes were confirmed.

For Cox, the results support the theories behind the neuroscience of learning.

When an uncertain prediction is confirmed — like successfully guessing which number will come up on a roll of dice — that confirmation activates reward processes in our brains. The result is a pleasant little chemical release that reinforces the value of the prediction. In Cox’s new studies, this neural-reward process made stereotyping more appealing than accuracy. Participants continued relying on stereotypes even when the feedback said that they were inaccurate.

“Our brains want our expectations to be supported,” says Cox. “Because of that reward engagement, we can start becoming addicted, in a way, to stereotyping. Simply understanding that this happens is an important way to check those assumptions and not let them influence your judgment.”

Published in the Winter 2022 issue