There is behavioral ecology, which looks closely at the difference different ecologies make to behavior and other features of animals and humans. There's evolutionary individual psychology, there's evolutionary social psychology. In Darwin's terms, evolution couldn't exist without variation, and variation is important in behavioral genetics. And so on, and so on. There are so many instances in which evolution actually sharpens the precision, I think, with which one can find out the importance of differences. We're interested in differences as well as commonalities.

I would be very surprised if on another planet we discovered a species as intelligent as humans that didn't have narrative, or didn't have art in general.

Popper and Nabokov are very different people in some ways - and I'm ready to devote large chunks of my life to both of them. Popper didn't think much of words but thought ideas mattered, and Nabokov didn't think much of ideas, but words mattered, and so on. But both of them had a sense that this is a world of infinite discovery, unending discovery. That quest to discover more in any direction is what I think drives me, and what drives humans, when they're doing the most interesting things.

In fiction the story lives the more everyone comes to life, the more each character seems to exist in his or her own right.

Everything is humanities. The sciences are a form of the humanities. They involve traditions of inquiry; they involve social engagement with ideas. They do not happen with a naked brain going out and encountering a nonhuman world. And the better we understand ourselves, the better we can do science, as well. So I don't see them - the sciences and the humanities - as being at all different.

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.

Scientists, to give them credit, do not think of the humanities in a negative way. It's the bureaucrats who want to cut costs who think, Well, here's something that's not booming at the moment, let's slash it.