Paulina Kernberg (who, with O. F. Kernberg, continues to enlarge an impressive body of theory and clinical data on the borderline states) here presents a tightly organized description of the ways in which the borderline adolescent differs from the normal. The stages in development of the borderline are compared with times of achievement of the same developmental tasks in normal preschool, latency, and adolescent children. Areas of difficulty which are explored are: reality testing, affects, ego functioning, superego functioning, experience of self, sexual identity, object relations (in some detail), oedipal situation, fantasies, cognitive functioning, and vulnerability to psychotic episodes.