Abstract

According to many scholars, prosociality, in particular altruism and empathic concern, is considered an important motivational factor both in adulthood and in the development of morality. So far, a large number of studies have addressed the development of children’s first-party prosociality and their third-party understanding of moral norms separately. In particular, there is much evidence that during the second year of life, young children develop empathic concern and sympathy for others in need in prosocial situations. Moreover, recent findings suggest that 18-month-old infants already show some rudimentary forms of norm understanding in at least dyadic conventional situations. This rudimentary norm understanding is interpreted as second-personal normative expectations. Finally, 3-year-old children not only have descriptive expectations about morality, but also normative ones as suggested by their enforcement of moral norms as unaffected bystanders. However, the interrelation between prosociality and morality, in particular the prosocial motivational source of the early sense of morality remains unclear. This thesis aimed to investigate the developmental origins of morality in young children. In particular, it examines the relation between the two main aspects of uniquely human cooperation – prosociality and morality – from a developmental perspective. These two aspects are of particular importance, not only because they each play a key role in maintaining the unique human capacity for large-scale cooperation but also because of their close relation to each other. The present thesis therefore focused on three guiding questions that are essential for the ontogeny of morality and its relation to young children’s prosocial motivation to understand, adhere to, and enforce moral norms: What are the developmental origins of morality? What is the underlying prosocial motivation for children's normative appreciation of morality? What is the scope of morality? Study 1 investigated the developmental origins of morality in 18-month-old infants. A novel eye-tracking paradigm was used to examine whether infants differentiate between prototypical moral and conventional violations. In a between-subjects-design, children watched the same video clip whose audio stream differed according to condition. In the first two conditions, an instructor told an observer to destroy a picture with a particular tool chosen from two available tools. In the moral violation condition, the instructor forbade the observer to destroy the picture at all. In all three conditions, the observer then grasped tool B and destroyed the picture, which led to three different situations. Infants differentiated between two types of conventional norm situations in their anticipatory looking. Moreover, they showed a larger relative increase in pupil dilation in response to a moral violation than to a conventional violation. These findings suggest that 18-month-old infants have third-party descriptive expectations about the distinction between conventional and moral violation situations. Moreover, they provide the first evidence that empathic concern may be a decisive capacity for the distinction between these two violation situations. Study set 2 looked at the underlying prosocial motivation for the appreciation of morality as a normative notion in 3-year-old children. In three experiments, children were given a third-party fairness task and two different prosocial tasks. To investigate whether the children have a proper norm understanding of fairness by looking not only at norm adherence, but also at norm enforcement, a spontaneous protest paradigm was used. In Experiment 1, children protested and corrected unequal allocations, suggesting a normative understanding of third-party fairness. Experiment 2 assessed whether children’s normative expectations about fairness have a moral dimension. To do so, children observed a distributor who followed or violated an authority’s command to allocate resources unequally. Again, despite the authority’s dictate to act unequally, children protested more against unequal versus equal allocations. In Experiment 3, results show that children enforced fairness norms by altruistic punishment in the sense of restorative justice. While in Experiment 1 and 2 I found a positive relation of protest behavior and emotional sharing, in Experiment 3 children’s altruistic punishment was associated with their own costly sharing behavior. Finally, in Study 3, I explored the scope of morality in 5-to 6-year-old children in a typical intergroup context. Here, I investigated whether decategorization – a candidate mechanism to overcome in-group bias by emphasizing the individual person – would lead preschoolers to treat in-group and out-group members equally when sharing resources in a dictator game. I found that preschoolers shared more resources with an in-group than with an out-group recipient when social category membership was emphasized. When individuating information was emphasized, however, children shared the same with in-group and out-group individuals. Taken together, the empirical studies of this dissertation provide a novel overview of the prosocial roots of children's developing morality. In particular, the present findings suggest that the ability to feel sympathy may be critical for the development of the moral-conventional distinction and that 18-month-old infants, at minimum, have third-party descriptive expectations about that distinction. The ontogeny of fairness norms can be characterized as moral in that it is associated with 3-year-old children’s developing concern for the welfare of others in different contexts. The presentation of out-group members as individuals may be a powerful tool to reduce in-group bias and to foster equal treatment of in-group and out-group members in 5- to 6-year-old preschool children.