They don’t think it’s a joke, they’re quite serious.
In “SuperCooperators,” Nowak argues that two of his mechanisms, indirect reciprocity and group selection, played an important role in human evolution. Think of a proto-simian trying to figure out whether to trust another in an exchange: Should I provide sex now for food and protection later? The proto-simian may have observed the behavior of its prospective partner, or it may not have; chances are good that others have, though. Reputation becomes important. The proto-simian evolves into a hominid, with a bigger brain allowing for more precise communication about reputation. Moral instincts evolve to produce shame, guilt, trust, empathy; social intelligence and conscience are born. Before you know it, Yogi Berra is summing it all up: “Always go to other people’s funerals, otherwise they won’t come to yours.” Language, cognition and morality, Nowak argues, are evolutionary spinoffs of the fundamental need of social creatures to cooperate.
Believe it or not, they are serious about parrallel universes too!