Autistic children are often said to lack a "theory of mind" (an implicit capacity which involves the person postulating the existence of mental states and then using these to explain and predict another person's behavior). Devoid of such a metarepresentational capacity, autistic individuals cannot symbolize the world around them and hence have impairments in pretend play, empathy, and social cognition. This Theory of Mind hypothesis implies that social deficits in autism are secondary in nature, i.e., resulting from other symptomatic features of the syndrome, and implies that some social behaviors may not be impaired in autism, specifically those social behaviors not demanding a metarepresentational capacity. Evidence is presented to indicate that, in contrast to predictions derived from the Theory of Mind hypothesis, social deficits in autism include very basic and early-emerging socially adaptive behaviors which are typically present in normally developing infants prior to the time at which even the most basic metarepresentational skills are thought to emerge. In addition, scores on the Socialization and Motor Skills domains of the Vineland Adaptive Behavior Scales (Revised) were lower for autistic children than for a nonautistic control group even when viewed relative to mental age. Thus, autistic social deficits are seen as being primary rather than secondary and pervasive or generalized rather than discrete. (Contains 25 references.) (JDD)