Is there anything that makes human beings special? You might think language does: it's pretty unlikely that dolphins could read this blog, let alone write it. But other species do have communication systems, some of which are quite sophisticated. Studies show that crows, for example, can hold grudges against specific people for many years—and can let their crow friends know which of us ought to be attacked. (Moral: be nice to crows!)

That leads us to a second theory, though: maybe it's our morality that makes us special. When crows attack people who were mean to their friends, that could easily be an evolutionarily acquired set of instincts, rather than the crow equivalent of the Ten Commandments; crow revenge is just a mechanism for ensuring crow survival. The problem here is that we see all kinds of genuinely altruistic behavior in non-human species: elephant moms collaborating to raise each other's children, monkeys rejecting food that's not distributed fairly, dolphins helping beached whales escape back into the ocean. (Meanwhile, humans are being cruel to each other in more ways than we can count.) The more you look at the non-human world, the harder it is to make a case for us being radically distinct.

Perhaps the best approach is to look at how our moral codes are transmitted. We articulate them, write them down, and teach them to our children—in ways that seem to differ from what happens elsewhere. Consider this fascinating fact: by the age of 7, a chimpanzee produces as much food as it consumes. Its childhood is essentially over. With humans, this doesn't happen until we're 15 at the earliest; and some of us (naming no names) are still supporting our offspring, well into their 20s or even 30s. Human beings have a considerably longer childhood, and that allows one generation to teach a bunch of things to the next. That really does seem to be something that makes us different from other animals.

It's true that instruction happens elsewhere: orca moms, for example, teach hunting techniques to their orca pups. But it doesn't happen on nearly the same scale or with nearly the same consequences. Here you are, reading words on an electronic screen, no doubt sitting inside a impressively-engineered building, with automobiles and other machines operating all around you. For better or worse, human beings have transformed their environment to an unprecedented degree—more than beavers with their dams, birds with their nests, and even ants with their underground cities—and they've used culture to do that. So, are we "special" after all? Our guest will help us decide—it's scuba-diving philosopher Peter Godfrey-Smith, whose latest book is Living on Earth: Forests, Corals, Consciousness, and the Making of the World.