Do as I Say, Not as I Do by Sharon Begley FROM NewsWeek

Scientists have long bickered over whether hypocrisy is driven by emotion or by reason—that is, by our gut instinct to cast a halo over ourselves, or by efforts to rationalize and justify our own transgressions. In other moral judgments, brain imaging shows, regions involved in feeling, not thinking, rule. In "the train dilemma," for instance, people are asked whether they would throw a switch to send an out-of-control train off a track where it would kill 10 people and onto one where it would kill one. Most of us say we would. But would we heave a large man onto the track to derail the train and save the 10? Most of us say no: although the save-10-lose-one calculus is identical, the emotional component—heaving someone to his death rather than throwing an impersonal switch—is repugnant, and the brain's emotion regions scream "Don't!"