Racial bias is often discussed in psychological terms—as a defense mechanism, a product of emotional immaturity, a way to project one’s fears and insecurities onto others.

But what if the causes of racism, and potential solutions, are more a matter of one’s environment? Could a region’s long history of racism create social and economic disparities that trigger prejudiced thoughts?

That intriguing question is raised in a new study, which finds a strong link between a region’s racial legacy and the implicit, or unconscious, bias of its current-day inhabitants.

Among white residents, “counties and states more dependent on slavery before the Civil War display higher levels of pro-white implicit bias today,” a research team led by University of North Carolina psychologist B. Keith Payne writes in the Proceedings of the National Academy of Sciences….

Pacific Standard Magazine