When Julius Caesar was repeatedly stabbed in a Senate meeting in 44 B.C., it wasn’t just Brutus, Cassius, or the other 60 “liberators” who were killing him — it was, in their minds, “the people.” ...

Once while I was jogging along Lake Michigan, I came upon a large crowd surrounding a middle-aged man lying supine on the ground. I stopped to assess the scene and saw the man wasn't moving—at all.

Does this sound familiar? You witness a car accident on the freeway. You decide not to stop or call the police because you assume that someone else has likely seen the accident and made the call ...

Certain messages can drive Internet users to take action in the face of cyberbullying, although the diffusion of responsibility on the Internet works similarly to that in direct contacts, say ...