When the chef's special at the local diner makes us ill, we don't order it in the future. But we'll step up to the plate time and time again after being beaned with a baseball. Clearly, people hang onto some bad associations and disregard others. Now, new research shows that's true for social groups too: whites and blacks are much more likely to hold onto negative associations of each other than to those within their own race.
In the animal world, such distinctions may result from evolution. Like us, rats learn by association, and studies indicate these associations may aid survival. When the rodents drink poisoned sugar water that makes them nauseous, for example, they're likely to avoid such "treats" for a while. But when the poison is substituted with foot shocks, the rats continue to go back for the sweet stuff. From an evolutionary perspective, this selectivity makes sense: Poisonous food is a much bigger problem than shocks in the wild. Mahzarin Banaji, a psychologist at Harvard University in Cambridge, Massachusetts, and colleagues examined whether the same selectivity applied to human race relations.
To test this, the researchers had black and white undergraduates view pictures of black and white adult males with neutral expressions. To associate these images with a negative experience, half the images of both races were paired with a mild shock. Past studies that used similar images without shocks suggested whites were more fearful when shown pictures of blacks than whites. The opposite was true of blacks.
The new question was how long this pattern would persist. So the undergrads were shown the images again, this time without the shocks. Fear responses were measured using electrodes that tracked the activity of sweat glands. Whites were no longer scared when they saw pictures of whites, and blacks weren't scared of fellow blacks. But surprisingly, whites continued to show a fear response when shown pictures of blacks, and vice versa, they report 29 July in Science.
"We carry with us a baggage of the past," says Banaji, who believes that this natural inclination towards fearing "outsiders" may have developed for safety reasons that are no longer necessary. The team also found that individuals who had been involved in interracial romantic relationships show diminished magnitude of this fear bias. This suggests that experience can change negative associations of another race.
"It's a very clever study," says Michael Gazzaniga, a psychologist at Dartmouth College in Hanover, New Hampshire. "It's the kind of research that will really sort out the underlying mechanisms for why these prejudices are so hard to get rid of."