There are several theories and models that help to understand more clearly about prosocial behavior. Among them, negative state relief model and kin selection theory are easier to understand why we help people and who are the people we tend to help in different situations.
The negative state relief model was introduced by Schaller and Cialdini in 988. They claimed that pro-social conduct stems from egoism rather than altruism, and that people help others to reduce stress when confronted with a difficult circumstance. This approach also explains why individuals get dissatisfied and leave. Also, walking away will helps to relieve tension. Humans have a natural desire to improve their moods. They can be lowered by engaging in any mood-enhancing action, such as assisting, when it is accompanied with positive value such as smiles and appreciations. Therefore, this model seeks to explain how one situational factor sadness relates to wanting to aid others. T
his idea claims that, at least in certain circumstances, a momentary sensation of melancholy will lead to a greater motivation to help others. A person who is upset because a close friend has just canceled a scheduled visit is more likely to assist a stranger in pushing his or her automobile out of a snowdrift. Why would being in a bad mood make you more inclined to help others? This is for selfish reasons, according to this view. People have been socialized in such a way that they have been rewarded for assisting others. People absorb this over time and find it satisfying to serve others. When a person is depressed, he or she feels compelled to improve his or her mood, and believes that assisting another person would do so. Simply said, when individuals are unhappy, they may be more willing to help others in the hopes of making themselves feel better. No matter what is an individuals condition at the point of helping others, they help them selflessly.