Negativity bias in infants' expectations about agents' dispositions

This study investigated 6- and 10-month-old infants' abilities to infer others' preferences based on social interactions using looking time and choice measures. Infants were randomly assigned to either a helping/neutral or hindering/neutral condition. Those in the helping/neutral condition were first familiarized with a helping event, in which an agent helped a circle climb a hill, and a neutral event, in which another agent followed the same path as the helping agent but had no interaction with the circle. During the test phase, the circle approached either the helper or the neutral agent. In the hindering/neutral condition, the infants were familiarized with a hindering event, in which an agent hindered the circle from reaching the top of the hill, and a neutral event, in which another agent followed the same path as the hindering agent but had no interaction with the circle. During the test phase, the circle approached either the hinderer or the neutral agent. For the looking-time measure, infants in the hindering/neutral condition looked reliably longer at the approach-hinderer than at the approach-neutral agent event, whereas those in the helping/neutral condition looked for equal amounts of time at both test events. These results suggest that the infants expected the circle to avoid the hinderer but did not expect it to approach the helper. In the choice task, infants chose the helper more often than the neutral agent and the neutral agent more often than the hinderer, suggesting an ability to generate their own preferences for a particular agent based on the valence of helping and hindering actions. This research demonstrates infants' sensitivity to the moral valence of agents' social interactions, which may serve as a foundation for advanced socio-moral reasoning. Statement of contribution What is already known on this subject? Research on infants' ability in social evaluation has established that even preverbal infants can distinguish between positive and negative social interactions. Infants as young as 6 months of age can distinguish between helping and hindering actions and can generate their own preference towards helpful agents. What does this study add? The present study sheds light on infants' ability to infer a third-party's preference, which is a more challenging task for the infants than generating their own preference. Specifically, 6- and 10-month-old infants could infer others' preference for the neutral agent over the hinderer. Such results demonstrate infants' sensitivity to the moral valence of agents' social interactions and provide an evidence of negativity bias in social evaluation.