In his famous 1959 Rede Lecture, "The Two Cultures," C. P. Snow argued that there existed a worrying divergence and growing incompatibility between two sorts of intellectual: scientists and literary intellectuals. Alas, almost 50 years later, many of the problems Snow identified remain and have probably even grown: witness the dominance of post-modernism, post-structuralism and other woo in the humanities. (This despite pointed and seemingly decisive criticisms).
So it's certainly a good thing that there is a group of researchers, Literary Darwinists, who are helping, in a modest way, to bridge the chasm from both ends. Jennifer Schuessler, writing on the NYT blog Paper Cuts, reviews a recent addition to this literature: Comeuppance: Costly Signaling, Altrusitic Punishment, and other Biological Components of Fiction by William Flesch. (Full disclosure: I haven't actually read the book, only about it). Flesch, professor of English Literature at Brandeis, seems to have solid humanities credentials, which means it's harder to portray Literary Darwinists as consisting solely of cold-hearted and naive scientists trying to colonize the humanities. Imagine that, scientists and English professors working on a single research program...
While I haven't read Flesch's book, I have ventured into other parts of the Literary Darwinist literature, mainly Joseph Carroll's work, and, speaking generally, I think it's exactly the sort of thing that should be happening. I don't know the field nearly well enough to have strong opinions, or to take sides in particular debates, but it's clear evolutionary psychology needs some account of literature and art generally. If we are aiming to provide a naturalistic (and pomo/nonsense-free) understanding of human behavior, it's clear we can't shy away from tackling distinctively human activities such as the creation and enjoyment of literature. Moreover, I would be extremely surprised if knowledge of our evolved mental architecture did not contribute to literary studies - so it's hardly only a matter of literature constituting a 'problem' for scientists to solve, a Darwinian perspective on literature might end up enriching the humanities.
(See also: D. T. Max's "The Literary Darwinists" in the NYT Magazine and Harold Fromm's fantastic "The New Darwinism in the Humanities": Part 1 [pdf] and Part 2 [pdf]).