A pervasive developmental disorder characterized by severe deficits in social interaction and communication, by an extremely limited range of activities and interests, and often by the presence of repetitive, stereotyped behaviors.
*American Heritage Dictionary
A serious disorder appearing in childhood and characterized by the child’s refusal to relate to other people and severely limited use of language. The cause of autism in children is unknown, but researchers generally feel that it lies in a malfunction of the central nervous system, not in the way parents have treated them or in other aspects of their environment. The term is sometimes applied, more loosely, to adults who are extremely self-absorbed and who see things in terms of their hopes and fantasies rather than realistically.
*American Heritage New Dictionary of Cultural Literacy, Third Edition
A developmental disorder that appears by age three and that is variable in expression but is recognized and diagnosed by impairment of the ability to form normal social relationships, by impairment of the ability to communicate with others, and by stereotyped behavior patterns especially as exhibited by a preoccupation with repetitive activities of restricted focus rather than with flexible and imaginative ones.
*Merriam-Webster’s Medical Dictionary
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