Social Influences on Early Fairness Expectations in Toddlers: Siblings, Peers, and Caregivers

This study examined how social factors such as parental mental state language, sibling presence, and preschool attendance influence their expectations of fairness in 18‐month‐old toddlers. Fifty‐four toddlers participated in a nonverbal fairness task and a picture‐description task with their caregivers. We also collected questionnaire data concerning the presence of siblings and preschool attendance. The fairness task involved an animated scenario with a mouse distributing bananas to monkeys, measuring the infants' attention to equal and unequal outcomes. The picture‐description task evaluated how caregivers used mental state language when discussing morally relevant illustrations with their toddlers. We found no significant link between parents' use of mental state language and toddlers' fairness expectations. Similarly, having siblings did not appear to influence these expectations. In contrast, toddlers who attended preschool demonstrated increased sensitivity to unfair outcomes. These results highlight the importance of early social interactions involving peers in preschool environments in the development of fairness expectations in toddlers.