Just started reading Sex at Dawn which I feel an obligation to approach with an extra measure of skepticism because it draws arguments from a field particularly vulnerable to just-so stories (evolutionary psychology) in order to support a thesis I already agree with (monogamy is for the birds). Inevitably Darwin comes up, which reminded me of the two coherent ideas I’ve ever had about Darwinism.
Coherent idea #1: Evolution selects for traits of species, not individuals. Most of the time this distinction is obscured by the fact that what is good for the individual is also good for the species, but there are some striking mismatches. Consider chickens. You’d be hard pressed to find a species less likely to go extinct anytime soon. And why? Because they’re fat, lay yummy eggs, and are absurdly easy to kill. Which is hard luck for each individual chicken, but great for chickens as a whole.
Coherent idea #2: Here is the first sentence of Sex at Dawn:
Forget what you’ve heard about human beings having descended from the apes. We didn’t descend from apes. We are apes.
Leaving aside the relevance this particular rhetorical flourish has for the authors’ argument, opening with it is clearly a good way to win over the kind of educated, cosmopolitan, scientifically-minded person likely to be reading this book. (It’s difficult to come up with a term for this type that doesn’t lapse into political cliché, though lately I’ve grown fond of the phrase “liberal elite” because it makes us sound like a bunch of Marines.) Some people draw deep emotional sustenance from the notion of being a tiny speck in a great cosmic swirl, while the same thought fills others with horror. The relative centrality of human beings in the big scheme of things is rightly an empirical question, but partisans on both sides are motivated by aesthetic considerations. Monkey trials are just a proxy war over which image the universe you find more beautiful. Which, like, fine. That happens all the time. But why should a particular visceral response to The Origin of Species correlate so consistently with a whole raft of seemingly unrelated beliefs? (Like, say, that monogamy is for the birds.) There’s no reason a priori to expect these things to hang together, but they do.