I just attended a few hours ago the Senior Common Room dinner at Dudley House and saw the excellent talk of Nicholas Christakis. He is MD, PhD occupying no less than three chairs at Harvard on top of being master of Pforzheimer House. The talk was a popularizing summary of his research on social network theory and was extremely well delivered. I thought I'd share here the TED talk of Prof. Christakis which is very similar to the talk I heard.