Bloodlust: On the Roots of Violence from Cain and Abel to the Present

THROUGHOUT HISTORY AND ACROSS CULTURES, the most common form of violence is that between family members and neighbors or kindred communities-in civil wars writ large and small. From assault to genocide, from assassination to massacre, violence usually emerges from inside the fold. You have more to fear from a spouse, an ex-spouse, or a coworker than you do from someone you don't know.

In this brilliant polemic, Russell Jacoby argues that violence erupts most often, and most savagely, betwee...