It shouldn't have been newsworthy. Just a few years ago, it wouldn't have provoked much of a reaction. But a smiling teenager and a drumming Native American have caused a firestorm of commentary, invective, heated emotions, and calls for violence. What is it that causes otherwise intelligent people to seemingly turn into halfwits when confronted by such non-events? What provides the template for the stereotyped and 'proper' response to the encounter we've all seen repeatedly and which has...