This chapter considers the fact that intelligence and achievement can be predicted from infancy and has theoretical implications. A classic issue in the study of intelligence is whether there is a single, general intelligence or whether there are multiple intelligences. The debate as to whether the nature of intelligence is continuous or discontinuous over age has a long history in the field of developmental psychology. One approach to understanding the biochemical bases of disordered intellectual functioning early in life is to study the effects of the common bodily biochemicals on cognitive functioning in populations with known neurological dysfunction. The study of the origins of intelligence in infancy by measures of early cognitive functioning may aid in clarifying theoretical issues, contribute to a methodologically integrated study of intelligence across a number of scientific disciplines, and, eventually, aid in reducing the incidence of intellectual disability.