E.O. Wilson writes: Evolutionary biologists have searched for the grandmaster of advanced social evolution, the combination of forces and environmental circumstances that bestowed greater longevity and more successful reproduction on the possession of high social intelligence. At present there are two competing theories of the principal force. The first is kin selection: individuals favor collateral kin (relatives other than offspring) making it easier for altruism to evolve among members of the same group. Altruism in turn engenders complex social organization, and, in the one case that involves big mammals, human-level intelligence.

The second, more recently argued theory (full disclosure: I am one of the modern version’s authors), the grandmaster is multilevel selection. This formulation recognizes two levels at which natural selection operates: individual selection based on competition and cooperation among members of the same group, and group selection, which arises from competition and cooperation between groups. Multilevel selection is gaining in favor among evolutionary biologists because of a recent mathematical proof that kin selection can arise only under special conditions that demonstrably do not exist, and the better fit of multilevel selection to all of the two dozen known animal cases of eusocial evolution.

The roles of both individual and group selection are indelibly stamped (to borrow a phrase from Charles Darwin) upon our social behavior. As expected, we are intensely interested in the minutiae of behavior of those around us. Gossip is a prevailing subject of conversation, everywhere from hunter-gatherer campsites to royal courts. The mind is a kaleidoscopically shifting map of others, each of whom is drawn emotionally in shades of trust, love, hatred, suspicion, admiration, envy and sociability. We are compulsively driven to create and belong to groups, variously nested, overlapping or separate, and large or small. Almost all groups compete with those of similar kind in some manner or other. We tend to think of our own as superior, and we find our identity within them.

The existence of competition and conflict, the latter often violent, has been a hallmark of societies as far back as archaeological evidence is able to offer. These and other traits we call human nature are so deeply resident in our emotions and habits of thought as to seem just part of some greater nature, like the air we all breathe, and the molecular machinery that drives all of life. But they are not. Instead, they are among the idiosyncratic hereditary traits that define our species.

The major features of the biological origins of our species are coming into focus, and with this clarification the potential of a more fruitful contact between science and the humanities. The convergence between these two great branches of learning will matter hugely when enough people have thought it through. On the science side, genetics, the brain sciences, evolutionary biology, and paleontology will be seen in a different light. Students will be taught prehistory as well as conventional history, the whole presented as the living world’s greatest epic.

We will also, I believe, take a more serious look at our place in nature. Exalted we are indeed, risen to be the mind of the biosphere without a doubt, our spirits capable of awe and ever more breathtaking leaps of imagination. But we are still part of earth’s fauna and flora. We are bound to it by emotion, physiology, and not least, deep history. It is dangerous to think of this planet as a way station to a better world, or continue to convert it into a literal, human-engineered spaceship. Contrary to general opinion, demons and gods do not vie for our allegiance. We are self-made, independent, alone and fragile. Self-understanding is what counts for long-term survival, both for individuals and for the species.