My last year at the University of Virginia, I took a masters-level Applied Sociology class. There I learned that small changes in our public spaces—placement of the exit on the bus, arrangement of an apartment complex courtyard—can lead to huge changes in group behavior. Ever since, I’ve been fascinated by forces that influence us in ways...

The two young men had been high school friends. One was Black, one was white. The Black man went missing. He had last been seen with the young white man, his friend. The white man schemed with his half-brother to shoot the young Black man and rob him. The brothers buried the Black man in a shallow grave, and the white man’s wife allegedly later...