The role of prescriptive norms and knowledge in children's and adults' causal selection.

A widely discussed discovery has been the influence of norms on causal selection. Confronted with scenarios in which 2 agents contribute equally to an effect, adult participants tend to choose the agent who is violating a norm over an agent who is conforming to a norm as the cause of the outcome. To date, this effect has been established only in adult populations, so its developmental course is unknown. In 2 experiments, we investigated the influence of norm violations on causal selection in both 5-year-old children and adults. In particular, we focused on the role of mental state ascription and blame evaluation as potential mediating factors in this process. To this end, the knowledge status of the agent in question was varied such that she either was or was not aware of her norm transgression. Results revealed that children and adults assigned blame differently: Only adults were sensitive to the knowledge of the agent about norms as a mitigating factor. Crucially, however, despite its different sensitivity to knowledge ascription in children and adults, blame assignment in both age groups affected causal selection in the same ways. The relevance of these findings for alternative theories of causal selection is discussed.