Take a look at this video, it is very interesting:
I haven't read his book on the topic (yet) but I've done quite a lot of internet research and found out that one of Haidt's conclusions seems to be the following:
Morality binds and blinds. This is not just something that happens to people on the other side. We all get sucked into tribal moral communities. We circle around sacred values and then share post hoc arguments about why we are so right and they are so wrong. We think the other side is blind to truth, reason, science, and common sense, but in fact everyone goes blind when talking about their sacred objects. Morality binds us into ideological teams that fight each other as though the fate of the world depended on our side winning each battle. It blinds us to the fact that each team is composed of good people who have something important to say.
It is also quite interesting the research concerning the morality libertarians tend to have:
http://www.yourmorals.org/blog/2012/08/new-research-on-the-moral-psychology-of-libertarians/
I find Haidts' research to be quite interesting, but also have some reservations about it. I mean, if it is all based on a primitive morality, why do so many people change their ideologies? If it all traces back to primitive moral instincts, why were different ideologies created through history? Take, for instance, the rise of the Tea Party and the Occupy movement, are their both just the result of our primitive minds? Can they really be traced back to our ancestors?
I'm not also very sure about its ying-yang moderate take on politics. A hundred years ago, the average moderate was a racist, and two hundred years ago the average moderate supported slavery. Also, the fact that two (or more) sides disagree doesn't necessarily mean that neither of them got it right.
Although, the guy gates it very right when he says that there are good people on all ideologies, that we shouldn't discriminate people because of their ideologies, and that there are plenty of intelligent people who support ideologies we dislike or we find disgusting. But also, what I find depressing about Haidts' reseach is that the average libertarian mind is so different that maybe we'll never have any big impact on others peoples minds. :(
Haidt's research is certainly interesting and can be used to better understand the people we are trying to convince. This said, I find his research biased when it comes to Libertarians, I've tried the questionaire he talks about in the video, and one of the problems is that most of the questions presuppose that the problem must be solved by government. It's the way these questions are set up that makes it look like Libertarians don't care about any of those things, when we do, we simply want to satisfy those values by different means.