Why do human beings spend so much time telling each other invented stories, untruths that everybody involved knows to be untrue? People in all societies do this, and do it a lot, from grandmothers spinning fairy tales at the hearthside to TV show runners marshaling roomfuls of overpaid Harvard grads to concoct the weekly adventures of crime fighters and castaways. The obvious answer to this question — because it's fun — is enough for many of us. But given the persuasive power of a good story, its ability to seduce us away from the facts of a situation or to make us care more about a fictional world like Middle-earth than we do about a real place like, oh, say, Turkmenistan, means that some ambitious thinkers will always be trying to figure out how and why stories work.
The latest and most intriguing effort to understand fiction is often called Darwinian literary criticism, although Brian Boyd, an English professor at the University of Auckland in New Zealand and the author of “On the Origin of Stories,” a new book offering an overview and defense of the field, prefers the term “evocriticism.” As Boyd points out, the process of natural selection is supposed to gradually weed out any traits in a species that don't contribute to its survival and its ability to pass on its genes to offspring who will do the same. The ability to use stories to communicate accurate information about the real world has some obvious usefulness in this department, but what possible need could be served by made-up yarns about impossible things like talking animals and flying carpets?
Boyd's explanation, heavily ballasted with citations from studies and treatises on neuroscience, cognitive theory and evolutionary biology, boils down to two general points. First, fiction — like all art — is a form of play, the enjoyable means by which we practice and hone certain abilities likely to come in handy in more serious situations. When kittens pounce on and wrestle with their litter mates, they're developing skills that will help them hunt, even though as far as they're concerned they're just larking around. Second, when we create and share stories with each other, we build and reinforce the cooperative bonds within groups of people (families, tribes, towns, nations), making those groups more cohesive and in time allowing human beings to lord it over the rest of creation.