This research studied undergraduate students as they increased their daily prosocial behaviors and reported their sense of life satisfaction for each day. Life satisfaction was also determined by physical appearance and self-esteem. Overall, students with low/medium satisfaction with their physical appearance experienced higher life satisfaction after increasing prosocial behaviors. Acting prosocially may provide a self-esteem boost for individuals who are not satisfied with their physical appearance and allow them to experience positive recognition from others for their actions rather than for their appearance.
Source: Personality and Individual Differences https://www.sciencedirect.com/science/article/abs/pii/S0191886917306487?via%3Dihub