Eleven-Month-Old Infants Preferentially Look at Helpers But Do Not Reliably Evaluate Inconsistent Actors

Developmental psychology has provided some evidence that infants evaluate agents who engage in prosocial and antisocial acts: Infants selectively reach for and look at those who have treated third parties prosocially versus antisocially. This previous work has tended to present infants with actors whose behaviors are entirely prosocial or entirely antisocial. Studies introducing even minor variation into an actor's behaviors have yielded null results with infants in the first year of life, suggesting that infants find it difficult to evaluate others who behave even mildly inconsistently. That said, it may be that past studies were poorly designed to test infants' evaluations of inconsistent actors. The present, preregistered experiments further explored 11-month-old infants' (N = 141) ability to evaluate inconsistent actors, using an online testing format and pre-recorded puppet shows depicting helping and hindering interactions. In Experiment 1, infants selectively looked to consistent helpers over consistent hinderers, conceptually replicating past findings via an online preferential looking procedure. We then adapted the same methods to examine infants' evaluations of actors who behave mildly inconsistently. In Experiment 2, infants showed mixed evidence of evaluating inconsistent actors who performed a single inconsistent act after 4 consistent ones, preferring to look at more versus less prosocial actors in one preregistered analysis, but not in other analyses. Furthermore, infants did not find the inconsistency unexpected, suggesting successful evaluation may have stemmed from failing to notice the inconsistency and evaluating the inconsistent actor based on its earlier behavior. In Experiment 3, we put the single inconsistent action first, before the 4 consistent ones, to further test whether infants can evaluate inconsistent actors. Here, infants showed no evidence of successfully evaluating inconsistent actors. These findings suggest that while infants prefer agents whose actions are consistently prosocial versus antisocial, they struggle to evaluate those whose actions are even mildly inconsistent.