A bold, provocative history of our species finds the roots of civilization's success and failure in our evolutionary biology. We are living through the most prosperous age in all of human history, yet people are more listless, divided and miserable than ever. Wealth and comfort are unparalleled, and yet our political landscape grows ever more toxic, and rates of suicide, loneliness, and chronic illness continue to skyrocket. How do we explain the gap between these two truths? What's more, what can we do to close it?