Three new books reveal how we deal with suffering and trauma.

A child who is bullied by her playmates may kick her kitten in retaliation. Passing pain to others is not just a human trait—payback can also be seen in many animals. In Payback: Why We Retaliate, Redirect Aggression, and Take Revenge (Oxford University Press, 2011), husband-and-wife team evolutionary biologist David Barash and psychiatrist Judith Lipton explain how we evolved such vengeful behavior, why it occurs (it turns out our brains are hardwired to redirect hostility), and how we can prevent it.

At age five Boris Cyrulnik was orphaned after his parents were deported to a concentration camp. In Resilience (Tarcher/Penguin, 2011), Cyrulnik, now a renowned neuropsychiatrist, relays his personal trauma as well as the stories of people who survived war, genocide and other painful experiences. Through his research, Cyrulnik discovers how resilient humans are. He reveals, for instance, that an abused child's brain can return to normal size if the child is placed with a loving foster family.

Humans have a tendency to dehumanize other humans. In Less Than Human: Why We Demean, Enslave and Exterminate Others (St. Martin's Press, 2011), David Livingstone Smith posits that this behavior is rooted in human nature. Smith, a professor of philosophy at the University of New England, explores the history, psychology, biology and philosophy of how humans perpetuated atrocities such as the Holocaust and the genocide in Rwanda. —Victoria Stern