White people who haven't been exposed to diversity have trouble processing mixed-race faces—and that could cause them to have greater racial biases, researchers say.  

A new study in the journal Psychological Science had people categorize photos of black, white, and mixed-race faces on a computer screen. Subjects from areas with less racial diversity had a harder time classifying the mixed-race peoples' faces, indicating that their environments limited their ability to understand race.

To find out if this lack of understanding could have bigger implications, researchers asked another group with a similar background to complete the same task, and then look at more faces. They then had to determine how trustworthy they thought these people were. Those who had trouble detecting mixed-race people's races were also more likely to consider them untrustworthy. 

Diana Sanchez, an associate professor of psychology at Rutgers University and one of the study's authors, told NTRSCTN in a statement that these results indicate that "for white individuals, limited exposure to racial diversity can influence your level of bias towards mixed-race individuals through a visual process."

We don't like the feeling of not being able to 'place' someone, and this feeling is amplified for people with little exposure to diversity.

For some, this bias is also rooted in the frustration of not being able to "place" someone right away.

"We don't like the feeling of not being able to 'place' someone, and this feeling is amplified for people with little exposure to diversity," University of Hawaii professor Kristin Pauker, another author of the study, told NTRSCTN in a statement. 

"​People typically respond to mixed-race individuals with confusion because they don't easily fit into racial categories," Sanchez said. "This is why so many multiracial people encounter the question, 'What are you?'"

On top of that, mixed-race people often deal with exclusion from multiple communities due to not being fully one race or the other, she added. 

In order to combat the bias that comes from growing up in a homogenous place, Sanchez suggested that people go to places or engage in activities that involve racially diverse groups. 

"Being aware of these biases is the first step in preventing bias in the future," she said.