The Dallas Morning News republished this article by Nicholas Wade of the NYT in this Sunday's "Points" section of the paper. I was pleasantly surprised to see it there.
Is ‘Do Unto Others’ Written Into Our Genes?
Many people will say it is morally acceptable to pull a switch that diverts a train, killing just one person instead of the five on the other track. But if asked to save the same five lives by throwing a person in the train’s path, people will say the action is wrong. This may be evidence for an ancient subconscious morality that deters causing direct physical harm to someone else. An equally strong moral sanction has not yet evolved for harming someone indirectly.
Full article from the NYT
A link to the author's site
I plan to buy/read this book and discuss further, just wanted to give a snippet so I didn't forget! :)