Six- to 12-month-old infants use emotional response, agent identity, and motion cues in associated learning of social events

Abstract

Studies have demonstrated that infants as young as 3 months old can distinguish between events containing prosocial and anti-social implications in theater play (Hamlin et al., 2007, 2010). However, the way infants are able to do so is still not fully understood. Here we study the roles of emotional responses, agent identity, and motion in animated social interactions among 6-to-12-month-old infants. Our Experiment 1 tested whether emotional response enhances infants' differentiation between characters in standardized prosocial and antisocial events. At the habituation stage, twenty-seven 6-to-12-month-old infants watched events depicting a climber being helped or hindered to climb up a hill by another character. These events evoked the climber's associated emotional expressions (laughing after being helped or crying after being hindered). In the test stage, the infants viewed two test events with new contexts – the laughing (or crying) climber approached the character who had previously either helped him climb up (consistent with the habituation), or hindered him (inconsistent with habituation). Infants looked significantly longer at the consistent condition, demonstrating that they associated differential emotional responses to the social events, and could apply this knowledge to new contexts. Experiment 2 was conducted to determine what association was learned. Infants might have used the character (who) or the action (what) or the combination of both (who did what) to distinguish events in Experiment 1. We habituated twenty-eight 10-to-12-month-old infants with the same helping/hindering events. Afterwards, novel events defined by: (1) a new character, or (2) a new motion direction, or (3) a new character with a new motion are presented in the test stage. The looking time significantly recovered from the last habituation trial in all three conditions. Our results suggest that emotional responses enhance infants' associated learning in social context, and both agent identity and motion direction are acquired during learning.