Psychologists have known for years that a person’s race and gender can subtly influence other people’s reactions to them. Lab tests have shown, for example, that when white people view pictures of other whites, they often associate those pictures with such words as “honest,” “loyal” and “trustworthy” slightly more quickly than when they’re shown pictures of black people.

But whether that bias translates into decision-making outside the lab has been debatable. New research published online in April in the Proceedings of the National Academy of Sciences now suggests that such bias could translate into action.

Elizabeth Phelps, PhD, a neuropsychologist at New York University, working with California Institute of Technology postdoctoral fellow Damian Stanley, PhD, and Harvard University cognitive psychologist Mahzarin Banaji, PhD, asked 50 racially diverse participants to look at 300 racially diverse photos and rate how trustworthy they found the people in the pictures. The researcher also gave the participants a standard implicit bias test.

They found that regardless of the participants’ race, those with a stronger implicit pro-white bias rated white people as more trustworthy than black people, and that people with stronger pro-black bias were more likely to rate other black people as trustworthy.

In a related experiment, the researchers asked the participants how much money they’d be willing to co-invest with the pictured person. People with an implicit pro-white bias said they’d invest more money with other white people than with black people, and vice versa. In effect, the researchers found that your business partner’s race could subtly influence your trust in him or her.

In real life, people make economic decisions based on more information than just their business partner’s race, Phelps says, so implicit bias might have more recognizable effects in snap decisions, such as whether to lend someone money on the street or choosing to interact with one bank teller over another.

—M. Price