Does this book represent a change in your politics? After all, a commitment to human nature has traditionally been associated with a conservative fatalism about violence and skepticism about progressive change. But Better Angels says many nice things about progressive movements such as nonviolence, feminism, and gay rights.
No, the whole point of The Blank Slate was that the equation between a belief in human nature and fatalism about the human condition was spurious. Human nature is a complex system with many components. It comprises mental faculties that lead us to violence, but it also faculties that pull us away from violence, such as empathy, self-control, and a sense of fairness. It also comes equipped with open-ended combinatorial faculties for language and reasoning, which allow us to reflect on our condition and figure out better ways to live our lives. This vision of psychology, together with a commitment to secular humanism, has been a constant in my books, though it has become clearer to me in recent years.
How and why has it become clearer?
Though I have always had a vague sense that a scientific understanding of human nature was compatible with a robust secular morality, it was only through the intellectual influence of my wife, the philosopher and novelist Rebecca Newberger Goldstein, that I understood the logic connecting them. She explained to me how morality can be grounded in rationality, and how secular humanism is just a modern term for the world view that grew out of the Age of Reason and the Enlightenment (in particular, she argues, from the ideas of Spinoza). To the extent that the decline of violence has been driven by ideas, it’s this set of ideas, which I call Enlightenment humanism (pp. 180–183), which has driven it, and it offers the closest thing we have to a unified theory of the decline of violence (pp. 694–696).
For future reference, I'm also linking to an interesting story at the New York Times on African-American atheists.