People who do crosswords often find that when they go and do something else the answer to a clue they have been wrestling with pops into their head spontaneously. Dutch researcher Ap Dijksterhuis looked into the issue of subconscious decision-making in a study of 352 undergraduates. Half of them knew a lot about football while the other half weren't interested in it. The students were asked to predict the results of four matches; some straight away, others after a couple of minutes thought and others after being distracted for a couple of minutes by a mental-arithmetic task. The students who didn't know much about football had the same amount of success however long they took with their predictions but the 'expert' students were more accurate after being distracted than when they made an instant decision or had spent time thinking about it. Dr Dijksterhuis thought that this might be because while the students were being distracted their subconscious brain was working on the problem free from the biases of their conscious mind.
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