Mental retardation, learning disabilities, and intellectual giftedness have long been separated as different fields. In the past decade research findings suggested a continuity within the general intelligence spectrum which place the gifted on one extreme and the retarded on the other, as well as a two dimensional taxonomy of intellectual exceptionalities. Based on psychological studies of human abilities and human information encoding processing, and the biographical evidence of eminent people and specific giftedness of savants, a bivariate model of intellectual exceptionality is proposed in this study. This model links all intellectual exceptionalities together with normal people, gives a clear picture about the location of each specific group at the human information encoding level, and suggests the use of a bivariate distribution to roughly estimate the population of each specific group. (Contains 71 references.) (Author)