1.

A difference between traditional economics and behavioral economics is that traditional economists assume that all human beings are rational. However, behavioral economists do not hold this notion, although they do not imply that humans are irrational; they state that humans make mistakes by making choices that fail to maximize their satisfaction and acknowledge that it is not that it is irrational or crazy. Another difference is that traditional economists believe that individuals update their beliefs and opinions based on the new information received; on the other hand, behavioral economists believe that the context in the decision-making process has a significant effect on a decision reached by an individual.

2.

The new branch of economics is justified as it enhances the realism of economic assumptions with the application of psychological concepts as economic behavior is a scope of both the form of people's actions and the study of economics. An individual's economic behavior gets influenced by several factors, i.e., external factors like demography and internal factors like an individual's psyche.