People overestimate groups they find threatening – when 'sizing up' others, bias sneaks in

You might make a quick and exaggerated judgment about what kind of neighborhood you’re in based on the people or flags you see. David Levingstone/DigitalVision via Getty Images

Places are not just physical, but also social.

For instance, around the North Carolina campus where we met, we knew certain bars based on the students who frequented them — the “Duke bars” versus the “UNC bars.” Or, when traveling, we may try to guess whether most of the patrons at a restaurant are tourists – and if so, go elsewhere.