With inequality rife throughout the world, scientists have been hard at work trying to reverse the trend. The latest breakthrough? Biased may be eradicated while you sleep.

Researchers at Northwestern University, Chicago tested men and women between the ages of 18 and 30. The tests are publically available and evaluate a person’s prejudices. These were used to establish a baseline of views.

“These biases are well-learned,” said Dr. Xiaoqing Hu, a postdoctoral researcher at the University of Texas at Austin and lead author of the study. “They can operate efficiently even when we have the good intention to avoid such biases. Moreover, we are often not aware of their influences on our behavior.”

The participants then completed a series of “counter-stereotype trainings”- they were told to press ‘correct’ whenever a female face appeared next to science or math words and whenever a black face was next to words such as ‘honor’ or ‘cheer’. Specific sounds were played each time they correctly labeled the pictures.

The participants were then asked to take a 90 minute nap. Upon reaching deep sleep, the scientist replayed the specific sounds associated with woman-science and black-positive pairings from earlier.

Incredibly, when the subjects woke and retook the prejudice tests, they were found to be 50 percent less biased. A week later, they were still 20 percent less biased.

“It is somewhat surprising that the sleep-based intervention could have an impact that was still apparent one week later,” said Hu. “The usual expectation is that a brief, one-time intervention is not strong enough to have a lasting influence.”

The team hopes that this study could be expanded and used for real world application to reduce biases based on race, gender, religious affiliation, weight, and more. However, the researchers admit that more tests need to be run before the method can be used on a large scale.

“We didn’t have people interact with or make decisions about other people, so that sort of experiment is needed to know the full effects of the methods we used,” said Dr. Ken Paller, director of the cognitive neuroscience program and one of the researchers from Northwestern University. “But we suggest that modifying unconscious social bias is likely to influence the extent to which decisions are influenced by racist or sexist attitudes.”

Still, some scientists worry about the ethical concerns involved with manipulating people while the sleep. Two German scholars who reviewed the study, Dr. Gordon Feld and Dr. Jan Born, of the University of Tubingen in Germany offered commentary warning of the dangers of influencing people who are in “a state… without willful consciousness and therefore vulnerable to suggestion.”