Resumen
Different social sciences study human beings. Economics is one of them and it is focused on a specific field of human action and social cooperation. The entire human collaboration is based on significant moral and ethical standards. If we want to understand how people are involved in economic (and other social) relationships, we need to understand the human nature. There are many scientists that consider human beings to be closed to animals, often being dominated by impulses and feelings difficult to be controlled. An inter-disciplinary science has been developed ? behavioral economics that provide an interpretation to human action from this perspective. The idea to consider human beings closer to animals (social or not) is an argument to introduce a third party (the state) that should regulate and control the human actions do not become aggressive or disruptive. The state is viewed as panacea to these imperfections associated to the human way of acting and cooperating. Crisis is considered to be determined or enforced by such imperfections. This paper discusses the idea of rationality in human action and argues against this common approach about its nature.