Morality binds people into groups. It gives us tribalism, it gives us genocide, war, and politics. But it also gives us heroism, altruism, and sainthood.

In accounts of men in battle, there is an incredible adrenaline rush from group-versus-group conflict. The fervor and passion of partisans is clearly rewarding; and if it's rewarding, it involves dopamine; and if it involves dopamine, then it is potentially addictive.

Human rationality depends critically on sophisticated emotionality. It is only because our emotional brain works so well that our reasoning can work at all.

I'll suggest that the happiness hypothesis offered by Buddha and the Stoics should be amended: Happiness comes from within, and happiness comes from without. We need the guidance of both ancient wisdom and modern science to get the balance right.

I think the greatest work in social psychology from the 1950s and '60s is enormously important. I wish every high school kid could take a course in social psychology. I think we're making enormous strides in understanding the brain. These aren't yet giving us great insights, but I feel like we're on the verge of it. In five or ten years this basically searching the brain is really going to change things.

I think Republicans need to take income inequality more seriously. Not because I favor equality of outcomes. I do not. I think the Right is correct to stress merit and earned rewards, not handouts and forced equality. But I think what Republicans are blind to is that power corrupts.

Even if you have a brain predisposed to liberalism, you might end up with some conservative friends or find inspiring conservative role models who could be very influential on you, and that could send you down a different track in life.