"Elves are... lower-variance. You can grab a hundred random Elves and they'll probably all be peaceful and responsible, at least when it matters. If you grab a hundred random humans thirty of them will make terrible neighbors and ninety of them will go pretty much wherever their incentives and the path of least resistance lead them and a couple of them will be sociopaths and a couple of them will have solemnly devoted their lives to something stupid that they think is for the greater good and maybe, if you got the right hundred humans, you'll get one who's good all over, but even if it wasn't the right hundred humans they'll mostly have some virtues and those are as solid as Elf virtues."