Our reasoning capacity sets us apart from other animals. But reason is frequently prone to error. Why then did we evolve with a capacity for reason at all?  This is a question that has vexed Dan Sperber - with Hugo Mercier he has been researching the topic. Dan Sperber discusses their research and conclusions with Nigel Warburton for this episode of the Philosophy Bites podcast. Philosophy Bites is made in assocation with the Institute of Philosophy.