I read Jonathan Haidt's book The Righteous Mind, and may have a full review eventually. It's getting some quite nasty commentary from the left, due to its both-sides-do-it-can't-we-all-get-along conclusions. Haidt presents himself as a standard-issue liberal who has, through the course of study, come to appreciate conservatism for something other than mere selfish stupidity, and thinks that we all have to do the same. This bland bipartisanship infuriates a certain kind of leftist.
I'll reserve my own judgement about all that. But I wanted to note that some of the virulent reaction to this from the left actually works to disprove Haidt's thesis. Among the six dimensions of morality Haidt identifies, "Loyalty" is one of the three he says that liberals are generally deficient in, or do not appreciate, or do not factor into their own judgements. Yet here Haidt is getting dumped on essentially for the sin of apostasy, the quintessential sin against loyalty. Those angry leftists sure do seem to have a highly tuned sense of loyalty after all.
Yes this is only based on a random smattering of blog comments, but I thought the reflexive irony or whatever it is was so sweet as to be worth noting.
Here's a more serious critique of Haidt's sloppiness, and here's a humorous leftist jibe at former leftists.