A moment spent working on something else or taking a break altogether allows the brain's unconscious thought process to take over, American psychologists believe. When the brain kicks back into gear, the conscious thought process will pick up on the solution, they found.
The discovery was made by a team of scientists who asked 130 volunteers to conduct a word association experiment.
Half the group were told to break off from their test to concentrate on something entirely different for five minutes.
The results showed that those who spent time focusing on a different task were much quicker at solving the first task when they returned to it than the group that had stuck with it.
The research, which is led by a team at Northwestern University in Illinois and published in the September issue of the journal Psychological Science, appears to contradict previous evidence that the distraction of emails and text messages can lower the IQ more than twice as much as smoking marijuana.
Professor Adam Galinsky, who led the study, said: "Conscious thought is better at making linear, analytic decisions, but unconscious thought is especially effective at solving complex problems. Unconscious activation may provide inspirational sparks underlying the 'Aha!' moment that eventually leads to important discoveries."