Do Infants Make Moral Judgments? Investigating Other Probable Explanations

In a now well-publicized study, Hamlin and Wynn (2011) concluded infants are born with an innate, not learned, tendency to judge the prosocial (moral) behavior of others. They based this conclusion on their study in which after watching a puppet show, 72% of infants chose the puppet that helped rather than the puppet that hindered a third puppet from attaining its goal. In the current investigation, we replicated their methods and extend their work by including a within-subject measure of infant puppet choice across repeated trials to assess the stability of infants’ choice. Twenty infants viewed a puppet show nearly identical to that described by Hamlin and Wynn (2011) and chose between two puppets (i.e., helper or hinderer) immediately following the puppet show. Although results were a similar to those of Hamlin and Wynn (2011) on the first choice trial (65% of infants chose the helper puppet on the first trial), infants did not consistently choose the helper across trials; several infants demonstrated a side bias, with 10 infants choosing puppets presented on the right or left side on at least four of five trials. Results are discussed in the context of the current replication crisis in psychology