This from Jonathan Haidt at Edge.org:
I study morality from every angle I can find. Morality is one of those basic aspects of humanity, like sexuality and eating, that can’t fit into one or two academic fields. I think morality is unique, however, in having a kind of spell that disguises it. We all care about morality so passionately that it’s hard to look straight at it. We all look at the world through some kind of moral lens, and because most of the academic community uses the same lens, we validate each other’s visions and distortions. I think this problem is particularly acute in some of the new scientific writing about religion.
When I started graduate school at Penn in 1987, it seemed that developmental psychology owned the rights to morality within psychology. Everyone was either using or critiquing Lawrence Kohlberg’s ideas, as well as his general method of interviewing kids about dilemmas (such as: should Heinz steal a drug to save his wife’s life?). Everyone was studying how children’s understanding of moral concepts changed with experience. But in the 1990s two books were published that I believe triggered an explosion of cross-disciplinary scientific interest in morality, out of which has come a new synthesis—very much along the lines that E. O. Wilson predicted in 1975.
Update: Another riff on the research that rounds out the issues can be found here.