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Approximately 15 to 20 out of 10,000 children have autistic-like behaviors.

Autism occurs in approximately 4.5 out of 10,000 live births. Approximately 15 to 20 out of 10,000 children have autistic-like behaviors.
As with many other developmental disabilities, autism is more prevalent in males than females.
Autism can manifest itself very differently in different individuals. Some individuals may be antisocial, some asocial, and others social. Likewise, some may be aggressive toward themselves and/or aggressive toward others.
Some individuals may have little or no language skills, some repeat or echo words or phrases, others may have normal language skills.
Many individuals with autism have an impairment of one or more of their senses. This impairment may cause their senses to be hypersensitive, hyposensitive, or may result in the person experiencing interference, such as a continual ringing or buzzing in the ears. This affects the ability to process incoming sensory information properly.

Symptoms According to the Diagnostic and Statistical Manual for Mental Disorders-IV, at least six of the symptoms listed below must be present with onset prior to age three in order to be diagnosed with autism. In addition, there needs to be a delay in social interaction, social communication, or symbolic or imaginative play.

Social Interaction:

  • Marked impairment in the use of multiple nonverbal behaviors 
  • Lack of spontaneous seeking to share interests and achievements with others 
  • Failure to develop age-appropriate peer relationships 
  • Lack of emotional reciprocity


  • Delay in or lack of spoken language development 
  • Lack of spontaneous age-appropriate make-believe or social imaginative play 
  • Marked impairment in conversational skill 
  • Stereotyped and repetitive use of language

Stereotyped patterns of behavior:

  • Preoccupation with at least one stereo-typed and restricted pattern of interest to an abnormal degree 
  • Stereotyped and repetitive motor mannerisms 
  • Inflexible adherence to nonfunctional routines or rituals 
  • Preoccupation with parts of objects 

Causes Some evidence suggests a genetic influence in autism. Twin studies have shown a greater prevalence among siblings who are identical twins than those who are fraternal twins.
Researchers have found abnormalities in the neural structure of the brain. For example, studies have shown that areas of the limbic system and cerebellum are significantly underdeveloped and smaller in autistic individuals. Studies have also shown abnormalities in brain chemistry. It appears that autistic individuals have elevated levels of serotonin in their blood and cerebral spinal fluid compared to those without Autism.

Some individuals are given medications to improve their general well-being. However, a medication that specifically and consistently targets the symptoms of autism has not been found.
Behavior modification, such as positive reinforcement and time-out, has been shown to be effective with some children in increasing appropriate behaviors and decreasing inappropriate behaviors. Communication skills and social behavior are primarily targeted to be increased, while self-injurious behaviors are targeted to be decreased.
Other areas of treatment that have received attention include sensory integration training, auditory integration training, visual training, and changing the individual's diet in order to eliminate particular foods.

Suggested Reading

  • Nobody Nowhere, by Williams, Donna 
  • Thinking in Pictures, by Grandin, Temple 

This information was provided by:
National Alliance on Mental Illness-Iowa
5911 Meredith Drive, Ste. E
Des Moines, Iowa 50322-1903
Phone: (515) 254-0417
(800) 417-0417