Warm hands, warm heart: heat helps cooperation

The Iterated Prisoner's Dilemma (IPD) task, designed to measure levels of cooperation, was completed by 60 students. Before performing the IPD task, participants were asked to hold either hot or cold objects. Analysis showed that individuals who held hot objects cooperated significantly more frequently when they had held the hot, as opposed to cold, objects.

Professor Workman said: "There is evidence that, during our evolution, the part of the brain responsible for processing interpersonal warmth came to 'piggyback' on top of the part of the brain responsible for physical warmth. So when we say we have 'warmed to someone' this is, in a sense, literally true."

We used prisoner's dilemma because it is a well-established tool for measuring cooperation, but we suspect that simply by giving someone a sensation of warmth they are more likely to cooperate under other circumstances. Perhaps next time you need to ask someone for a favour it might be worth making them a cup of tea first!"