Early developmental backgrounds of autistic and mentally retarded children. Future research directions.

A brief account of the main diagnostic distinctions between autism and mental retardation is provided, which serves as the basis for reviewing available evidence on possible commonalities and differences in the developmental backgrounds of these two groups of children. Systematic comparisons in the histories of the two groups have rarely been undertaken, yet they are crucial for understanding the agents and processes uniquely associated with the genesis of each condition. Specific suggestions are made on some fruitful avenues for such comparative research undertakings.