“With blind people,” she added, “the process is much slower as they piece together information about a person over time. Their thinking is deliberative rather than automatic, and even after they’ve categorized someone by race, they’re often not certain that they’re correct.”

Friedman, an assistant professor of sociology at the University of Delaware, interviewed 25 blind people to determine how they evaluate others. The study considered people who were born without sight as well as those who became blind later in life.

Friedman also considered prior research on what’s known as the “automatic visual processing” of sighted people.

The research found that, generally, the blind assign race only after they have extensive interaction with a person. These are not just fleeting moments, or quick casual encounters. They instead tend to rely on lengthier conversations and use of other senses, such as hearing and touch.