College of Liberal Arts

Unlearning Social Biases While We Sleep

Fri, May 29, 2015
Image by: planetchopstick (creative commons)
Image by: planetchopstick (creative commons)

Can we learn to rid ourselves of our implicit biases regarding race and gender? A new study lead by a postdoctoral fellow at The University of Texas at Austin indicates that sleep may hold an important key to success in such efforts.

Researchers have documented many unsavory consequences of common social biases. When playing a videogame with instructions to shoot only people carrying weapons, players were more likely to shoot unarmed targets when they were Black versus White. Bias also can be demonstrated in hiring decisions. For instance, scientists were more likely to hire male than equally qualified female candidates for research positions.

Even well-meaning people can be influenced by these biases without realizing it.

UT Austin postdoctoral fellow Xiaoqing Hu lead the study, conducted at Northwestern University, to find out whether learning to alter habitual reactions to other people could be enhanced during sleep, using a method called Targeted Memory Reactivation that pairs memory with sounds.  

Participants completed two training regimens, one designed to reduce racial bias and the other gender bias.

In the computerized training tasks, faces were paired with words that ran contrary to a stereotype. For example, female faces appeared with words associated with math or science, and Black faces appeared with pleasant words. There were two distinctive sounds during this training, one that came to be strongly associated with the women and science pairs and the other with the Black and pleasant pairs.

Following the training, participants took a nap. While they were in deep sleep and without their knowledge, one of the sounds was played repeatedly, but with the volume set low enough to avoid disturbing sleep.

The sleep procedure produced the selective benefits that the investigators expected. Bias reduction was stronger for the specific type of training reactivated during sleep. This relative advantage remained one week later.

“It is somewhat surprising that the sleep-based intervention could have an impact that was still apparent one week later,” said Hu, who was a Ph.D. student at Northwestern when he began the study. “The usual expectation is that a brief, one-time intervention is not strong enough to have a lasting influence. It might be better to use repeated sessions and more extensive training. But our results show how learning, even this type of learning, depends on sleep.”

Further experiments will need to examine whether these procedures can reduce the impact of implicit biases in important decision-making situations, but this research can broaden the discussion of what sorts of efforts can be made to combat social bias in society, researchers said.

“Unlearning Implicit Social Biases During Sleep” was be published May 29 in the journal Science. In addition to Hu, the paper is co-authored by Galen Bodenhausen, Ken Paller, Iliana M. Vargas and Jessica D. Creery of Northwestern, and by James W. Antony of Northwestern (now at Princeton University).

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