Sapiens were not stronger than Neanderthals or other animals. However, they possessed the skill of large-scale cooperation. Like today, humans cooperated with strangers. For example, most modern humans do not harvest their own bananas. Someone far away produces them; others ship them to our supermarkets, and employees sell them to us. We may not know any of these people, but they collectively help us get food. Most of humanity’s “big achievements,” like the moon landing, “were the result of cooperation between hundreds of thousands of people” (39). Other animals, like chimpanzees, do not cooperate in large numbers or with strangers. Ancient Homo sapiens were the only humans at the time who were capable of cooperating in large groups and with strangers: “So even though a single Sapiens wasn’t smarter than a single Neanderthal, Sapiens became much better at inventing tools and hunting animals. And if things ever came to a fight, 500 Sapiens could easily defeat 50 Neanderthals” (43).

Social insects, like ants, are the only other animal that cooperates in big numbers. Yet they never change the way they cooperate. Ants are always divided into the same five groups that play the same roles, like foragers or warriors, in their colonies.