We investigated children's positive emotions as an indicator of their underlying prosocial motivation. In Study 1, 2-, and 5-year-old children (N = 64) could either help an individual or watch as another person provided help. Following the helping event and using depth sensor imaging, we measured children's positive emotions through changes in postural elevation. For 2-year-olds, helping the individual and watching another person help was equally rewarding; 5-year-olds showed greater postural elevation after actively helping. In Study 2, 5-year-olds' (N = 59) positive emotions following helping were greater when an audience was watching. Together, these results suggest that 2-year-old children have an intrinsic concern that individuals be helped whereas 5-year-old children have an additional, strategic motivation to improve their reputation by helping.

Self-conscious emotions, such as guilt and shame, motivate the adherence to social norms, including to norms for prosociality. The relevance of an observing audience to the expression of negative self-conscious emotions remains poorly understood. Here, in two studies, we investigated the influence of being observed on 4- to 5-year-old children's (N = 161) emotional response after failing to help someone in need and after failing to complete their own goal. As an index of children's emotional response, we recorded the change in children's upper body posture using a motion depth sensor imaging camera. Failing to help others lowered children's upper body posture regardless of whether children were observed by an audience or not. Children's emotional response was similar when they failed to help and when they failed to complete their own goal. In Study 2, 5-year-olds showed a greater decrease in upper body posture than 4-year-olds. Our findings suggest that being observed is not a necessary condition for young children to express a negative self-conscious emotion after failing to help or after failing to complete their own goal. We conclude that 5-year-olds, more so that 4-year-olds, show negative emotions when they fail to adhere to social norms for prosociality.