Panda Community

There are many anecdotal reports, but few systematic studies, of aggression and violence in individuals with ASD. The limited data suggest that, in children with intellectual disability, autism is associated with aggression, destruction of property, and tantrums.[33]

Communication

About a third to a half of individuals with autism do not develop enough natural speech to meet their daily communication needs.[34]

Differences in communication may be present from the first year of life, and may include delayed onset of babbling, unusual gestures, diminished responsiveness, and vocal patterns that are not synchronized with the caregiver. In the second and third years, children with autism have less frequent and less diverse babbling, consonants, words, and word combinations; their gestures are less often integrated with words.

Children with autism are less likely to make requests or share experiences, and are more likely to simply repeat others' words (echolalia)[35][36] or reverse pronouns.[37]

Joint attention seems to be necessary for functional speech, and deficits in joint attention seem to distinguish infants with ASD:[9] for example, they may look at a pointing hand instead of the pointed-at object,[27][36] and they consistently fail to point at objects in order to comment on or share an experience.[9]

Children with autism may have difficulty with imaginative play and with developing symbols into language.[35][36]

In a pair of studies, high-functioning children with autism aged 8–15 performed equally well as, and adults better than, individually matched controls at basic language tasks involving vocabulary and spelling. Both autistic groups performed worse than controls at complex language tasks such as figurative language, comprehension and inference.

As people are often sized up initially from their basic language skills, these studies suggest that people speaking to autistic individuals are more likely to overestimate what their audience comprehends.[38]

Repetitive behavior

Autistic individuals display many forms of repetitive or restricted behavior, which the Repetitive Behavior Scale-Revised (RBS-R)[39] categorizes as follows.

Stereotyped behaviors: Repetitive movements, such as hand flapping, head rolling, or body rocking.

Compulsive behaviors: Time-consuming behaviors intended to reduce anxiety that an individual feels compelled to perform repeatedly or according to rigid rules, such as placing objects in a specific order, checking things, or hand washing.

Sameness is resistance to change; for example, insisting that the furniture not be moved or refusing to be interrupted.

Ritualistic behavior involves an unvarying pattern of daily activities, such as an unchanging menu or a dressing ritual. This is closely associated with sameness and an independent validation has suggested combining the two factors.[39]

Restricted behavior is limited in focus, interest, or activity, such as preoccupation with a single television program, toy or game.

Self-injury includes movements that injure or can injure the person, such as eye-poking, skin-picking, hand-biting and head-banging.[9]

No single repetitive or self-injurious behavior seems to be specific to autism, but autism appears to have an elevated pattern of occurrence and severity of these behaviors.[40]

Other symptoms

Autistic individuals may have symptoms that are independent of the diagnosis, but that can affect the individual or the family.[24] An estimated 0.5% to 10% of individuals with ASD show unusual abilities, ranging from splinter skills such as the memorization of trivia to the extraordinarily rare talents of prodigious autistic savants.[41]