The idea that self-interest underlies all human interactions is called the cost-benefit analysis by accountants, utilitarianism by philosophers, and by social psychologists. attribution theory social exchange theory cognitive dissonance theory the two-factor theory of emotion

social exchange theory

Explanation:

The social exchange theory suggests that we all interpret and rate all human interaction on the basis of the reward (benefits) and disadvantages or problems (cost) that we can get from them. This is both conscious and subconscious. On the basis of this benefits and cost analysis, we decide to whether continue the interaction or repeat it in future or to stop interacting with that person. Cost-benefit analysis also focuses on similar concept but in financial regards.