Piaget and Personality: A Cognitive-Developmental Hierarchy of Ego Defense

In this article, I will make the case that Piaget’s theory of egocentrism provides evidence for the relevance of his theory to the study of personality. It does so by providing the answers to the still open questions as to the conceptual status of Freud’s concept of ego defense. These are: (1) How does a positive adaptive species characteristic become a negative maladaptive individual personality trait? (2) What is the cognitive-developmental hierarchy of ego defenses? and (3) What is the species characteristic that all Freud’s ego defenses have in common? In order to make the case, it is required to refute the false claim that Piaget’s theory of intelligence is not related to the study of personality. It is also demanded in order to facilitate the work of clinicians, theorists and researchers working in the field of personality and child development.