The interesting aspect of his essay for me is contrasting the lense that academia looks at morality through with the way that religious people view morality. It is alway refreshing when liberal academics are able to recognize the bias that they bring to a subject and examine it.
A key point he makes is that you really can't trust the reasons that people give for why they think something is moral or immoral. As Haidt says, "People couldn't stop themselves from making up post-hoc explanations for whatever it was they had just done for unconscious reasons." In other words, we subconsciously make a moral judgment and then our conscious brain tries to fit a rational explanation to why we feel the way we do. We may come up with quite convincing reasons and really believe them without realizing that we reached that judgment for quite non-rational reasons. In other words, our morality initially comes from our gut feelings.
Academia has focused on fairness/justice and harm/care as the basis of morality. However these two foundations fail to explain the real world.
Most traditional societies care about a lot more than harm/care and fairness/justice. Why do so many societies care deeply and morally about menstruation, food taboos, sexuality, and respect for elders and the Gods?"He proposed three additional foundations of morality:
He calls these binding foundations because they bind groups of people together into hierarchical, interdependent social groups that regulate the daily activities of their members. By contrast he calls the first two foundations the individualizing foundations because they protect individuals from each other. People who self-identify as liberals base their morality primarily on the first two individualizing foundations whereas conservatives have morals based on all five foundations. Conservatives care about much more than just individual rights, they also care deeply about loyalty to their group, respect for authority, and purity.
I guess this would only be surprising to a liberal academic, but it does explain why academics and liberals are so tone deaf to the importance of certain beliefs to conservatives. One easy example is sexuality. Liberals want people to stay out of the bedroom. After all, what goes on between consenting adults is no one else's business because it doesn't hurt anyone (harm/care) and they wouldn't like other people intruding into their own personal lives (fairness/justice). The religious right, however, care deeply about other people's sexual practices because those practices are filthy or unnatural (sanctity/purity), violate God's law (authority/respect), and violate societal norms or decency (ingroup/loyalty).
A classic example comes from the movie "Milk" where Anita Bryant goes on a religious crusade to overturn laws that were passed to protect the civil rights of homosexuals. A more recent example of the same thing was the recent proposition 8 in California which pitted social conservatives against liberal over gay marriage. I find this example example particularly because it pits the individualizing moral foundations against the binding ones. The fact that time and time again the binding foundations seem to win over the individualizing ones is, I think, a clear statement of the relative importance to the human species of group cohesion over individuality. Nothing seems to bring us together more strongly than threats to our group identity.
So the crux of all of this is that morality seems to derive more from evolved gut feelings than from any kind of philosophical musing or rational process. Rationality mainly gets involved to justify those feelings and in some rare cases to override our baser instincts.