Carl Zimmer has an article in the April issue of Discover Magazine about how neuroscience is providing more and more evidence that morality is hardwired into the human brain. For example, there are two variants of a famous moral dilemma about saving the lives of five people who are about to be hit by a train. In the first version, you can throw a switch and thus kill one person (he or she would be hit by the redirected train; in the second, you can push a fat guy off a footbridge, who would fall on the tracks and thus stop the train. Most people tend to say they would throw the switch, but they would not push the guy to his death. It just does not feel right. The two versions of the dilemma also light up different areas of the brain, as shown by MRI imaging: we tend to use logic to reach a conclusion in the first case, but emotions play an important role when it comes to killing somebody without the indirectness of some intervening machinery. The reason for this probably is that evolution has hardwired our brains for the latter case, but there are no hardcoded, visceral responses to throwing a switch, even if we know that it leads to the death of another human being.
Such findings should be serious food for thought for those who argue that morality can only originate in the brains or souls or hearts (whatever, pick your favorite) of true believers, and you must be an immoral animal if you do not believe in some supernatural power. But I guess somebody who rarely thinks does not like too much food for thought.