The societies in which most humans live have changed dramatically over the past 10,000 years. At the end of the last ice age, all humans lived in hunting and gathering bands where nearly everyone was related, generalized reciprocity was the norm, families produced almost everything they needed, and group decision-making was consensual. In contrast, today most of us live in industrial nationstates where we will never meet most of our compatriots, economic exchange is the norm, families produce only the tiniest fraction of the goods and services they need, and political decisions are made through bureaucratic governments