Autism is a developmental disorder that occurs in about 1 in 150 children born in the United States according to the Centers for Disease Control and Prevention. The signs of autism show up before age 3 and continue to some degree throughout life. Those signs are most evident in speech, communication, social skills and behavior problems. Autistic individuals are often described as being on the "autism spectrum," which may range anywhere from mild, "odd" behaviors to low functioning individuals who need protection to keep from harming themselves. The disorder was popularized in the book and TV movie "Son Rise" by Barry Kaufmann in the late 1970s and later by the movie "Rainman" in 1988. Although each autistic person is different, certain key signs tend to be evident in anyone diagnosed as autistic.
Repetitive Movements
One key sign of autistic behavior is odd, repetitive movements. The movements may show up as hand flapping, rocking or twirling, according to the Yale Child Study Center. A musically inclined autistic person may play the same tune over and over. If the autistic person speaks, he may say the same words and phases repeatedly. In some cases the movements may be self-injurious such as hair-pulling, slapping or hitting himself.
Echolalia
Autistic people tend to have echolalic speech which repeats what a speaker said to the autistic person rather than building upon, answering and commenting on speech in conversation. Other behavioral signs which show inappropriate social responses include avoidance of eye contact, seeming indifference to speech or conversation and looking "through" nearby people as if unaware of them according to the Autism Research Institute.
Lack of Self-Preservation Skills
An autistic person will tend to seem unaware of real danger, like walking in traffic or getting too close to dangerous machinery. Early signs of autism include screening for deafness, because of the disregard the autistic person may have for sound of any kind. The Autism Research Institute includes signs like destroying his own toys, hitting or slapping himself as potential signs of autistic behavior.
Poor Social Skills
A key sign of autism is a poor display of social skills. An autistic child may not be able to engage in play with other children and may seem to be in her own little world. The Autism Research Institute states an autistic child can't seem to engage in imaginative play with others. As an adult, that autistic person can't have a conversation, work as a team nor behave cooperatively in any activity unless it includes repetitive motions that the person seems to enjoy, such as cutting food into symmetrical shapes or setting a table so that plates and silverware are displayed in a pattern that is pleasing to the autistic person.
Splinter Skills
While having severely diminished communication skills, an autistic person may display advanced musical or math skills. According to the Autism Research Institute, the autistic person may be able to play a complicated piece of music perfectly after hearing it only once, or he may be able to glance at an object and draw an exact copy of the object without referring back to the original, even though it may be in view. In the movie "Rainman," the autistic character portrayed by actor Dustin Hoffman could do complicated math problems and keep track of numbers of cards.
