capacity for evil. For both Bowles and I, certain aspects of our capacity to harm others emerges as an incidental byproduct of other capacities, and once this dynamic emerges, the combination of these capacities can evolve and change. What Bowles’ analysis misses, however, is the fact that parochial altruism could well be true, and so too could our shared capacity for killing with chimpanzees. As noted above, rates of killing among chimpanzees and several small scale societies are comparable, and so too are the costs and benefits to attackers and victims. This argues in favor of a shared history, and a shared adaptation. It does not mean that all aspects of killing in humans are similar, or that the human mind froze in a chimpanzee state with regard to its capacity to kill. It most definitely did not freeze. Unlike the lethal attacks by chimpanzees that are restricted to cases where groups attack lone victims, primarily from neighboring groups, we wreak havoc on a massive scale, with one on one, many against many, and one against many, including victims within and outside our core group. Unlike chimpanzees, even our young children have an appetite for violence that can be nurtured, as evidenced by the brutality of child soldiers around the globe. Unlike chimpanzees, individuals will sacrifice themselves for an entire group as evidenced most recently by suicide bombers in the Middle East. Unlike chimpanzees, we derive great pleasure from watching others suffer, from watching violent movies, seeing other animals fight, and imagining the decimation of an enemy. Our minds also generate ideological reasons to motivate violence at extraordinary scales — again, think of suicide bombers taking their lives for a God, as well as the reward of an idyllic afterlife. And when our minds break down, or when we are afflicted with particular disorders early in life, we are capable of experiencing bizarre appetites for violence, including the joy of eating the flesh of murdered vict