According to Salon's Laura Miller, author Brian Boyd gives a two-pronged explanation of the influence of fiction on human evolution:
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.
The second part is more convincing than the first (Madame Bovary showed us what happens to people who learn how to behave from books), and Miller expands on it in a sensitive and thought-provoking way:
The affection we feel toward fictional characters like Dorothy Gale or Tom Sawyer is akin to the warm belonging we seek among friends and family, drawing us into the kind of group affiliation that can spell the difference between life and death. The late novelist David Foster Wallace once told me that reading fiction made him "feel unalone — intellectually, emotionally, spiritually. I feel human and unalone and that I'm in a deep, significant conversation with another consciousness." That profound sense of comfort he described is, as he correctly perceived, quintessentially human, an incentive to keep connecting with each other despite our inevitable conflicts and tensions.
The idea that fiction reinforces human community seems like an interesting one, but it has its limits. When Boyd tries to expand his theories into "evocriticism," a way of looking at works of literature through an evolutionary lens, he goes astray. In his analysis of the Odyssey, he writes that Homer uses narrative techniques like "focusing on a larger-than-life yet sympathetic protagonist with a distinct goal" because he "understands that he must seize and hold his audience's attention." "But come on," writes Miller, "who doesn't know that?"
Looking at fiction as a vehicle for communal values may encourage this kind of simplistic criticism. Homer (if there even was one single Homer who composed the Odyssey, which is far from certain) likely knew that he had to be entertaining in order to get people to pay attention to his story, but the story itself is far more than a particularly effective social-togetherness machine. And literary criticism, at its best, is far more than an explanation of why art is useful. Really good writing about writing is an art in itself, a practice that adds to our enjoyment of words and the world in a way that has nothing to do with our ability to hunt or share food. It's interesting to think about how art might influence our evolution and vice versa, but this thinking is no substitute for the complex and joyful examination of literature that great criticism can provide. Boyd's ideas are interesting as anthropology, but anyone who's really interested in literature would do better to pick up a copy of Mimesis or Helene Cixous's Coming to Writing and Other Essays — they're a lot more fun, and, in the end, they might be truer.