How a Cow Catches a Sheep: Is action anticipation in infants based on rationality or frequency?

Abstract

The aim of social robotics is to make robots that are integrated in our daily life and cooperate with humans. For efficient cooperation, the understanding of actions of other agents is important. In Artificial Intelligence the general assumption is that humans will perform the actions that are the most rational way to achieve a goal. Infant studies about action anticipation performed by Gergely, Nádasdy, Csibra and Bíró, (1995) and Csibra, Gergely, Bíró, Koós and Brockbank (1999) are often cited as support for the viability of that assumption. The present study, however, investigates the possibility that action anticipation is based on the frequency of an action instead of rationality. To test this hypothesis we performed an experiment using a habituation paradigm in which we measured the looking time as well as the anticipation of 9- month-old infants when they observed an agent performing one out of two possible actions. We manipulated the actions insofar as one of the actions was the more frequent but also more inefficient one, whereas the other was the more efficient but also more infrequent one. The anticipation measurements showed evidence for the frequency hypothesis, whereas the looking times provided no evidence for either the frequency hypothesis or the rationality theory. Therefore, it could be interesting to see how action models in Artificial Intelligence based on frequency will perform in comparison with or in cooperation with existing models based on rationality.