NPR's Michel Martin led two challenging conversations about race this week, focusing on fearful perceptions of African-American men and how these fears play out in people's everyday lives. Guests including author and Georgetown University Law professor Paul Butler examined the research and the complicated emotions behind this fear.

"When you're in an elevator or walking behind somebody and you feel like you have to perform to make them feel safe, it's like apologizing for your existence," Butler says.

Others have already joined the conversation through social media. We heard from a white woman haunted by memories of being mugged by black men years ago, from a black pastor who has had the doors of some churches closed to him because of his race, and from another black man who described dealing with this fear as "heartbreaking."

Copyright 2016 NPR. To see more, visit http://www.npr.org/.