Development of means-end behavior in young infants: pulling a support to retrieve a distant object.

Three longitudinal studies are reported in which 6-8-month-old infants were tested on means-end problems involving pulling a cloth to retrieve a toy. Production of intentional means-end behavior increased between 6 and 7 months, but although 6-month-olds' behavior was unaffected by the presence or absence of a toy on the cloth, 7-month-olds more often produced means-end sequences when a toy could be retrieved. Infants' performance remained the same when the cloth was either attached to the toy or separate, suggesting that goal-subgoal conflict does not interfere with performance of means-end sequences. By 8 months, infants could appropriately adjust their means-end behavior to the distance of the toy. These results confirm J. Piaget's (1953) original description of a shift from transitional to intentional means-end behavior and suggest that development of means-end behavior involves acquisition of knowledge of appropriate means-end relations.