Incubation Effects in Problem Solving

Abstract : Does putting a problem aside 'to incubate' for a while really facilitate problem solving, and if so, why? We answer this question by reviewing the empirical literature, by reviewing existing theories of incubation, and by proposing a new more unified approach. We begin by defining incubation. Next, 17 studies of incubation are reviewed and their results compared. Factors that affect whether an incubation effect is obtained are discussed. These factors pertain to the type of problem studied, the length of the time period for problem solving before the incubation period, the length of the incubation period, and the type of activity during the incubation period. We also examine the role of individual differences in obtaining incubation effects. Finally, we propose a theory of incubation, whereby incubation effects depend upon an interaction between the cause of blockage in problem solving and cognitive mechanisms that act during the incubation period. Potential causes of blockage in problem solving are (a) the inability to generate new paths to solution and (b) stereotype. Critical cognitive mechanisms include (a) priming and (b) forgetting. Priming during a period of incubation helps on problems where the difficulty lies in generating new solution paths, whereas forgetting during an incubation period helps on problems where stereotype is blocking problem solution. Implications for further problem solving research on incubation, insight, and transfer are discussed. (kt)