Evaluate theories of Prosocial Behavior.

Pro-social behaviour fosters positive traits that are beneficial for children and society. It may be motivated both by altruism and by self-interest, for reasons of immediate benefit or future reciprocity. Evolutionary psychologists use theories such as kin-selection theory and inclusive fitness as an explanation for why prosocial behavioural tendencies are passed down gene-rationally, according to the evolutionary fitness displayed by those who engaged in prosocial acts. Encouraging prosocial behaviour may also require decreasing or eliminating undesirable social behaviors.

The purest forms of prosocial behaviour are motivated by altruism, an unselfish interest in helping another person. According to Santrock, the circumstances most likely to evoke altruism are empathy for an individual in need, or a close relationship between the benefactor and the recipient. However, many prosocial behaviors that appear altruistic are in fact motivated by the norm of reciprocity, which is the obligation to return a favor with a favor.

People feel guilty when they do not reciprocate and they may feel angry when someone else does not reciprocate. Thus some professionals argue that altruism may not exist, and is completely motivated by reciprocity. Either reciprocity or altruism may motivate many important prosocial behaviors, including sharing.

Researchers have also found that social exclusion decreases the likelihood of prosocial behaviour occurring. In a series of seven experiments conducted by Twenge et al., researchers manipulated social inclusion or exclusion by telling research participants that other participants had purposefully excluded them, or that they would probably end up alone later in life.