The main problem: The purpose of this article is to introduce the research and study discipline of economic psychology in relation to its theoretical development on economic choices and decisions and individual economic behaviour. Objective: Describe the birth and fundamental characteristics of the discipline of Economic Psychology related to economic choices and decisions. In addition, we want to provide arguments on the difficult and complex relationship between economics and psychology because Psychology and economics have very different approaches to the study of the choices and decisions of firms and individuals. Methods: The main method used for the development of this research is both deductive and inductive, i.e. a use of both classical research tools. The line followed is that of analysis made through historical context in which the discipline of economic psychology has developed. The research is based both on the analyses and study of the numerous books and article. Results and their significance: The research is an introduction to the fundamentals of the Economic Psychology.