Proceedings of the Annual Meeting of the Cognitive Science Society

Research beginning with Piaget reveals a change in infants’understanding of multistep, means-end action sequences:Whereas 12-month-old infants reason that (e.g.) one opens abox to access its contents, younger infants are more likely toreason that one’s goal is simply to open the box. Here weexplore the implications of this developmental change ininfants’ action understanding for infants’ social evaluations.Using a puppet show paradigm, we examined infants’evaluations of two agents who helped another agent to achieveeither the end or the means of a means-end sequence, bothbefore and after 12 months of age. In a subsequent preferencetest, 15-month-old infants reached for an End-Helper over aMeans-Helper, whereas 8-month-old infants did the reverse.These findings link infants’ evaluation of helpers to theirrepresentations of action plans, consistent with recentcomputational models of naïve psychology.