In the true prisoner's dilemma article, it doesn't appear to give any information about the cognitive algorithms the opponent is running. For this reason I answered noncommittally, and I'm not sure how useful the question is for distinguishing people with CDTish versus TDTish intuitions.

So did I. Also, in that particular scenario, I'd rather call for a referendum than decide for humanity by myself. I've thought about replacing saving 0/1/2/3 billion lives with receiving 3/2/1/0 kicks in the groin, but that would trigger near-mode thinking in me. Being given 0/500/1000/1500 dollars? Then I would definitely cooperate if I was convinced my opponent's cognitive algorithms aren't too different from mine.