I got to think of one book that treats this topic: Ernest Gellner's Reason and Culture: The Historic Role of Rationality. Gellner says that Descartes, whom the takes to personify early European rationalism (a notion which he, like Less Wrong, uses in the broad sense which includes empiricism) saw reason and culture ("custom and example") as enemies. Now culture is very similar to "identity", but on a social level. The rationalist criticism's of culture and identity are also very similar: they criticize parts of culture/identity that you, or your society, has acquired for accidental reasons, which there is no rationale for, and which are damaging in some way.

Gellner's argument in the rest of the book is complex and I don't remember it in any detail, unfortunately. The reviews I find on the internet are less than informative. Some parts of the book are quite idiosyncratic, as Gellner often was, but he is always very stimulating to read (though reading him does require a decent level of knowledge of history and of the great sociologists and philosophers). I think I recall some line of argument that says that reason hasn't defeated culture, as Descartes wanted, but rather that our culture been transformed in a rationalist direction - it has come to put a high value on reason and rationalism (that's essentially what I say below, though I'd forgotten where I'd got it from). I don't have the book, though, so I can't veryify that I remember correctly.