Problem Variables that Promote Incubation Effects

Three studies sought to determine whether incubation effects could be reliably generated in a problem-solving task. Experimental variables manipulated were the duration of the interval between two problem-solving opportunities and the activity performed by the problem solvers during the interval. A multi-solution anagram task was used which required problem solvers to generate five-letter words from the letters in a ten-letter “starter” word until they could produce no more words. After a break (the incubation period) the problem solvers returned to the anagram task anew. Some participants also engaged in an activity related to the anagram task during the break which was expected to prime potential solutions that would emerge during the second problem-solving attempt. In all conditions problem solvers were able to generate new responses after the break, thus demonstrating a reliable incubation effect. The optimal incubation period was between 15 and 30 min long. The priming task increased the number of solutions to the anagram task on the second attempt, suggesting that exposure to solution ideas during the incubation period may facilitate an incubation effect during problem solving.