I gave a couple of talks and Q&As last week at the U.S. Holocaust Memorial Museum. One of the questions that came up was whether we need to increase the store of human compassion in order to better deal with the problem of apathy in the face of genocide. Why has the world sat on its hands so often as mass murder has unfolded?

The final chapter of The Hidden Brain examines this issue, and suggests that unconscious biases in the way empathy works could be responsible for human apathy in the face of mass suffering. The most paradoxical conclusion of the research I write about is that as human suffering increases, it appears that our capacity to empathize with such suffering decreases. We are most able to behave compassionately, in other words, when the number of victims in need of help is one.