You don’t have to go abroad to see these ideas. You can find them in the Republican Party. Social conservatives see welfare and feminism as threats to responsibility and family stability. The Tea Party hates redistribution because it interferes with letting people reap what they earn. Faith, patriotism, valor, chastity, law and order — these Republican themes touch all six moral foundations, whereas Democrats, in Haidt’s analysis, focus almost entirely on care and fighting oppression. This is Haidt’s startling message to the left: When it comes to morality, conservatives are more broad-minded than liberals. They serve a more varied diet.

This is where Haidt diverges from other psychologists who have analyzed the left’s electoral failures. The usual argument of these psycho-*pundits is that conservative politicians manipulate voters’ neural roots — playing on our craving for authority, for example — to trick people into voting against their interests. But Haidt treats electoral success as a kind of evolutionary fitness test. He figures that if voters like Republican messages, there’s something in Republican messages worth liking. He chides psychologists who try to “explain away” conservatism, treating it as a pathology. Conservatism thrives because it fits how people think, and that’s what validates it. Workers who vote Republican aren’t fools. In Haidt’s words, they’re “voting for their moral interests.”

One of these interests is moral capital — norms, prac*tices and institutions, like religion and family values, that facilitate cooperation by constraining individualism. Toward this end, Haidt applauds the left for regulating corporate greed. But he worries that in other ways, liberals dissolve moral capital too recklessly. Welfare programs that substitute public aid for spousal and parental support undermine the ecology of the family. Education policies that let students sue teachers erode classroom authority. Multicultural education weakens the cultural glue of assimilation. Haidt agrees that old ways must sometimes be re-examined and changed. He just wants liberals to proceed with caution and protect the social pillars sustained by tradition.