Summary The findings of the neuropsychologic studies provide evidence of the selective involvement of higher order cognitive and neurologic abilities, suggesting that autism is a disorder of complex information processing. The saccadic eye movement studies provide evidence of a comparable selective pattern of dysfunction in the higher order circuitry of the brain, suggesting that the cognitive and behavioral abnormalities in autism are the result of the failure of the more advanced levels of neural systems development to evolve in autism. A great deal more research is needed to better understand the cognitive components of higher order cognitive abilities and their relationship to behavior in real life, the neural systems and neural connectivity that subserve them, and the course of development of these cognitive abilities and circuitry in autism and in normal individuals. Further understanding of these issues and of the genetic regulation of these brain developmental events will contribute significantly to the development of neurobiologically based interventions for autism and to the broader understanding of these issues relevant to many disorders of the central nervous system.