Charles Darwin was later to become something of an authority on worms, but he opened a huge can of them back in 1859 when he predicted in the final chapter of 'On the Origin of Species' that "psychology will be based on a new foundation", thanks to his theory of evolution by means of Natural Selection. Although I don't think the following is quite what he had in mind.
Most sociobiolgists might have dropped the name sociobiologists these days, but, as modern-day evolutionary psychologists—yes, I know they're not quite the same thing, but they are really—they continue to come up with any number of new suggestions—you'll note I don't call them theories—to explain the evolutionary advantages of all manner of human traits, from masturbation to Methodism. I'm sure some of these suggestions must have some merit—even the ones that aren't bleeding obvious—but it's pretty hard to sort the wheat from the chaff: unfalsifiable chaff, as it almost invariably is.
As Adam Sedgwick claimed he did on first reading On the Origin of Species, I laughed out loud last week when I came across the latest suggestion by evolutionary psychologists in New Scientist (I really must cancel my butler's subscription). Get this: it seems that the reason we read literature might be that it "could continually condition society so that we fight against base impulses and work in a cooperative way" because the characters in novels fall into groups that "[mirror] the egalitarian dynamics of hunter-gatherer society". Honestly, you couldn't make this stuff up. Well, I couldn't at least—although clearly someone is.
Note that they're not merely suggesting that novels often reflect the moral norms of society (which clearly is bleeding obvious); they're saying that the reason we read literature might (there's that word again) be to help re-enforce such social norms, thereby increasing our chances of getting on with each other and having more offspring. That's because reading literature and telling stories is a human trait, you see; and all human traits have to give us an adaptive advantage—otherwise we wouldn't do them. Obviously.
As you'll have gathered, I don't have much time for evolutionary psychology. Granted, most of the time, as in this case, it's nothing more than a little harmless fun which the newspapers love. But what happens when unwelcome human traits such as sexism, racism and supporting Manchester United are explained away by evolutionary psychologists? Sexists, racists and any Manchester United fans capable of parsing a sentence might then argue, "It is an evolutionary adaptation; it's perfectly natural; it's a good thing". The harmless fun suddenly begins to feel rather sinister.
The human brain is the most complex structure in the known universe. Its curious, difficult-to-define software by-product, the human mind, is, if anything, even more complex. Both brain and mind are perfectly valid subjects for scientific enquiry, but coming up with specious evolutionary explanations for whatever human trait happens to grab your fancy adds nothing to our understanding of what it is to be a member of one of the most interesting species on the planet.