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Cambridge University Science Magazine
Researchers from Northwestern University, Illinois, recruited 40 White participants. Without specific selection, they all showed an implicit racial and sexual bias. Chances are that you would have similar results (if you do not believe it, you can test yourself here: These biases can lead to discrimination, as many studies have shown. For example, job applicants have higher chances of being interviewed when their CV shows a typical White vs. Black name – despite equal qualifications.

The research team was able to reduce the biases with training. Participants had to pair Black faces with positive words and female faces with science words such as chemistry and maths. Each type of bias was associated with one sound. The exciting part of the experiment followed after the training: the subjects took a nap in the lab and when they entered the deep-sleep phase, the researchers played one of the sounds to them repeatedly. The sound presumably reactivates the memory of the counter-bias training and strengthens the effect.

Directly after the nap, the bias was even further reduced if participants heard the corresponding sound. The other bias remained unchanged. When the subjects returned after one week, the sleep-reactivated bias was still reduced, the other one had returned to the level before training.

The authors acknowledge that it is not clear how long these effects persist in the long term. We also do not know if these changes in bias have effects on everyday behaviour. But if they do, we may have found a cheap and easy way of reducing a bias and discrimination: sleeping it off!

DOI: 10.1126/science.aaa3841

Written by Julia Gottwald – PhD student at the Department of Psychiatry, twitter: @julia_gottwald