A review of life span research with the Twenty Questions Task: a study of problem-solving ability.

Research with the Twenty Questions Task which was aimed at investigating problem solving across the life span was reviewed. This research indicates that the use of an efficient problem-solving strategy increases during childhood and then decreases again during the later adult years. Investigations of the determinants of performance on the Twenty Questions Task indicate that both age and education are significantly related to performance. Training research further indicates that both young children and elderly adults are able to learn to use a more efficient strategy; modeling appears to be a very effective training technique. Attempts to facilitate the performance of elderly adults by means other than direct training have met with less success. No improvement in performance was obtained either in a study in which an attempt was made to increase elderly adults' motivation, in a study in which elderly adults were given additional practice with the Twenty Questions Task, or in a study in which an attempt was made to facilitate elderly adults' confidence in their ability to perform cognitive tasks. However, performance was facilitated when the demands of the task were made either so easy that the possibility of the use of an efficient strategy was obvious or so difficult that the necessity of using an efficient strategy in order to solve the problem was obvious. The results of all of the studies were discussed as fitting a model of life span cognitive development recently proposed by Denney.