This guide describes, from the perspecitve of J. Piaget's theories, the nature of intellectual handicaps and their significance for cognitive development, personality development, and interaction with the environment. A description of intellectual capacity and intellectual development is followed by an analysis of the role of intellectual capacity in personality dynamics and in a person's interaction with the environment. Among topics considered are intellectual function related to abstraction level and the role of emotional experiences in personality. The second section describes intellectual handicaps, reviews different levels and etiology, and examines the personality dynamics involved. The paper concludes with an analysis of intellectual handicaps and interaction with the environment. (CL)