Autism as a disorder in its own right was first proposed by Dr. Kanner in 1943, and it is interesting to note that the main features of autism he described then are still used for diagnosis today. The three abnormalities described by Kanner are necessary for the diagnosis of autism, regardless of domestic or foreign diagnostic criteria: 1) social developmental abnormalities; 2) communication abnormalities; and 3) behavioral and interest limitations. Of these, social developmental abnormalities are specific to autism. Symptoms of autism vary from person to person and for the same individual will vary with age. Abnormal development is usually evident by age 3, and some studies even suggest that early signs of autism can be detected in infancy. Examples include a lack of babbling and directional movements, a lack of imitation of sounds and hypersensitivity, and a dislike of change by 12 months of age. 1. Abnormal social development: Children are unable to make warm emotional connections with people. Children with autism do not respond to emotional parental behaviors such as smiles and hugs. They do not seem to enjoy being hugged or kissed. They are as unresponsive to parents as they are to strangers and show no interest in other children. There was little difference in their reactions to people and to inanimate objects. The characteristic expression is avoidance of gaze, i.e., lack of eye contact. 2. Communication abnormalities: language development is very late or completely lacking. In a few cases, language development can be normal, but by age 2, these abilities are partially or completely lost. Lack of speech is a sign of severe cognitive deficits. When children with autism grow up, about half can speak some useful speech, although there are still residual severe language impairments, such as misuse of prepositions or inappropriate repetition of other people’s words. Some children with autism are very verbal, but their language is a repetitive monologue rather than a communication with other people. Deficits in the ability to recognize the world can also affect nonverbal communication and play. Children with autism do not participate in imitative play at age 1, and later they are unable to play with toys in an appropriate way and have little imagination and creativity in play. 3. Interest and behavioral limitations: Compulsive demands for consistency are a stereotypical behavior for children with autism, and they become frustrated if their environment changes slightly. For example, children with autism insist on eating the same food, wearing the same clothes, playing the same games over and over again, and some are almost obsessed with spinning toys. Strange behaviors and quirks are common. Some children with autism like to make strange movements, such as spinning, repeatedly playing with fingers, clapping, and shaking their bodies; other children with autism may also have behaviors that are not significantly different from those of normal children. 4. Other characteristics: Children with autism may suddenly become angry or fearful without obvious triggers. They may show excessive hyperactivity and inattention, sleep disturbances or uncontrollable bowel movements, and some may show self-injurious behavior. About 1/4 of children with autism have a combination of seizures in adolescence. 5. Intelligence level: Dr. Kanner initially believed that children with autism had a normal IQ, but later studies found that 3/4 of children with autism were mentally retarded. Some children with autism show exceptional abilities in some areas, although they have impairments in other intellectual functions. Some children show strong abilities in some areas of memory or arithmetic skills, which cannot be considered “idiot genius”.