Facing up to racial fears all in the mind

Story by The Guardian
Written by Tim Radford 
May 9, 2005

Photographs of black faces trigger the brain's "alarm button" in almost two-thirds of both white and black people, according to the results of a study by American neuroscientists published today.

The findings could help explain the pervasive impact of racial stereotypes and the "are you thinking what I'm thinking?" effect.

They could also throw light on how people deal with their unconscious responses to ethnic minorities, outsiders or strangers, because when volunteers in the study were told to label the photographs with descriptions such as "African-American" the response changed.

The amygdala is a tiny bit of the brain which serves as an alarm bell: it sets off a cascade of biological changes that prepare the body to respond to danger long before the brain is consciously aware of any potential hazard.

Matthew Lieberman, of the University of California, Los Angeles, and colleagues report in the online edition of Nature Neuroscience that they asked eight African-American volunteers and 11 Caucasians to look at photographs of expressionless faces, black and white.

The scientists scanned their unconscious brain activity with functional magnetic resonance imaging. Five of the eight black volunteers showed a bigger amygdala response when they saw pictures of other black individuals than when they saw white faces. Seven of the 11 white volunteers produced the same result. There was nothing in the brain responses that revealed whether the viewers were white or black.

"Even people who believe to their core that they do not have prejudices may still have negative associations that are not conscious," said Dr Lieberman. "One theory is that people are likely to pick up the stereotypes prevalent in a society, regardless of whether their family or community agrees with those stereotypes."

When the team applied the words "African-American" to black faces, the amygdala response disappeared.