Sapiens: A Brief History of Humankind, by Yuval Noah Harari

Yuval Harari's Sapiens: A Brief History of Humankind is my favorite book of 2016. Harari argues convincingly that the root of human exceptionalism is our ability to collectively believe in shared fictions -- not just ideologies, but also legal entities and nation states. These fictions are central to facilitating human cooperation on a scale unmatched in the animal kingdom.