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

Evidence for a developmental shift in the motivation underlying helping in early childhood. Robert Hepach, Jan M. Engelmann, Esther Herrmann, Stella Gerdemann, Michael Tomasello. Developmental Science, February 21 2022. https://doi.org/10.1111/desc.13253

Abstract: 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.