<p>This study aimed to examine children’s altruism by introducing two new tasks, a social discounting task and a social dilemma task, with a sample of 1,621 children aged 7–12 years. In the social discounting task, the children chose between a hypothetical smaller reward for themselves or a larger reward which was shared with a variable number of other children. Participants’ social discounting rates were estimated by their pattern of responses across the eight choice trials. In the social dilemma task, modeled on typical parameters of a prisoner’s dilemma, the children chose between two options (i.e., cooperation and defection) where the hypothetical money outcome was partially determined by the friend’s choice. Developmental changes were hypothesized in both tasks, where social discounting rate and defection in social dilemma would decrease as a function of age. This hypothesis was supported, and moreover, an association between measures from these tasks was observed. The present study provides initial evidence of valid and age-appropriate assessments of social discounting and social dilemma in children as young as 7 years old.</p>