Illustrate about the imposition of behavior assumptions in analytical frameworks of modern economics?

Imposition of Behavior Assumptions:

The second one step for studying an economic issue is to create assumptions onto individuals’ behavior. Making suitable assumptions is of basic importance for obtaining an important economic theory or assessment. An important assumption modern economics makes regarding an individual’s behavior is which an individual is self-interested. It is a main dissimilarity between individuals and the other subjects-topics. The self-interested behavior assumptions are not merely reasonable and realistic, but also have a minimum risk. Still this assumption is not appropriate to an economic environment; this does not cause a big trouble to the economy even though it is applied to the economy. The rule of this game designed for self-interested individuals is probable also appropriate for altruists, but the reverse is probably not true.