Preference matters: Knowledge of beneficiary's preference influences children's evaluations of the act of leaving a choice for others

People value indirect prosocial actions that benefit others as byproducts of self-oriented actions. One example of such an action is the act of leaving a choice for others when selecting an item for oneself. In this study, we investigated how knowledge of the beneficiary's preference may influence children's evaluations of such actions. Children (n = 91, 4- to 10-year-olds) and adults (n = 43) were asked to evaluate characters taking a snack for themselves from a set of three items—two identical items and one unique item—in a way that either leaves a choice (two different items) or leaves no choice (two identical items) for the next person (the beneficiary). The beneficiary's preference was systematically manipulated as unknown, preferring the unique item, or preferring the item of which there are two. We found notable developmental changes: Children as young as 4 years of age understand that it is nicer not to take away the only thing others prefer; with age, children increasingly appreciate the value of leaving a diverse choice when the beneficiary's preference is unknown; however, when the beneficiary clearly prefers the item of which there are two, children increasingly think that it is nicer to leave two identical but preferred items than to leave a diverse choice. These findings reveal increasing flexibility and subtlety in children's social evaluation of indirect prosocial actions; their evaluation develops from a mere understanding of the value of preference to a flexible appreciation of both preference and choice.