"Art and literature need extreme sociality to a degree that even dolphins don't have. We are the only large mammalian species that has such intense sociality. There are some small mammals that have become eusocial - the mole rats - but that's a different thing. Humans are able to understand one another at very high levels, to cooperate in very large groups. Humans depend on one another in ways that are an absolute precondition to sharing the kinds of information that makes narrative possible."