On self-boundary: a study of the development of the concept of secrecy

The child's developing concept of a 'boundary' between an inner world of 'self' and an outer world 'non-self' is central to a number of systems of psychodynamic theory. The notion of boundary is also essential to Piaget. Despite the evident importance of the subject, there have been few attempts to discover the age at which this concept emerges. This study of 40 urban Australian children uses the development of the concept of secrecy as a marker. Most children attained this concept during the fifth year of life.