The role of frequency information and teleological reasoning in infants' and adults' action prediction.

This study investigates the contribution of frequency learning and teleological reasoning to action prediction in 9-month-old infants and adults. Participants observed how an agent repeatedly walked to a goal while taking the longer of 2 possible paths, as the shorter and more efficient path was impassable. In the subsequent test phase, both paths were passable. In the 1st test trial, infants and adults anticipated the agent to take the longer path. Unlike adults, infants kept anticipating movements to the longer path even after observing that the agent now took the more efficient path, indicating that the frequency of previous observations dominates action prediction. These results provide evidence, contrary to existing claims in the developmental literature, that frequency learning underlies action prediction in infancy, whereas teleological reasoning might gain importance later on in life.