For thousands of years, we’ve seen ourselves as inherently selfish creatures, driven by our genes to maximize pleasure. This is our original sin: We care about ourselves first and foremost, which is why we despise taxes, turn a blind eye to the suffering of others, and, in general, struggle to live a just life. But these pessimistic assumptions are mostly wrong, or at least woefully incomplete. In recent years, psychologists and neuroscientists have begun dismantling this view of human behavior. We may not be altruistic angels, but neither are we depraved hominids. For instance, it turns out that people have a natural aversion to inequality.