Symptoms of Autism

Updated: February 10, 2009

About.com Health’s Disease and Condition content is reviewed by the Medical Review Board

Autism Spectrum Disorders: Definitions

Autism is a pervasive developmental disorder which affects social and communication skills and, to a greater or lesser degree, motor and language skills. It is such a broad diagnosis that it can include people with high IQ’s and mental retardation - and people with autism can be chatty or silent, affectionate or cold, methodical or disorganized. So, what exactly is an autism spectrum disorder? These articles are a good place to get the basics:

All Autistic People Do Not Look Alike

There is a saying in the autism field: "if you’ve met one person with autism, you’ve met one person with autism." In other words: every person on the autism spectrum is unique, and one person's set of symptoms is just that … one person's set of symptoms! This is, in part, because autism is a spectrum disorder: you can be a little autistic or very autistic.

But there's more to it. An array of problems are relatively common among autistic people such as seizure disorders, gastrointestinal issues, mental retardation and mental illness. At this point, no one knows why these conditions are so common among people with autism spectrum disorders. It is possible that these additional conditions are indicators of different kinds of autism, each caused by a slightly different set of circumstances.

While the conditions listed above are more common among autistic people than among the general population, they are by no means universal among people on the autism spectrum. In fact, many autistic people have no apparent mental or physical illness at all.

Social and Communication Symptoms

Most of the time, autism is suspected in a child or adult because of deficits or stereotyped differences in social and communication skills. Some examples of these differences include:

Delayed or unusual speech patterns (many autistic children, for example, memorize video scripts and repeat them word for word with the precise intonation as the TV characters)
High pitched or flat intonation

Lack of slang or "kidspeak"

Difficulty understanding tone of voice and body language as a way of expressing sarcasm, humor, irony, etc.

Lack of eye contact

Inability to take another's perspective (to imagine oneself in someone else's shoes)

While many autistic people have terrific language skills, there are many who have no language at all. In between, are people whose verbal skills are idiosyncratic: They may be perfectly able to talk, but have a difficult time with conversation, small talk, and slang.

Sensory and Motor Symptoms

A majority of autistic people are either hyper or hypo sensitive to light, sound, crowds and other external stimulation. Some have both hyper and hypo sensitivities. This often results in autistic people covering their ears, avoiding or reacting negatively to brightly lit areas, or — on the other hand — crashing hard into sofas and craving strong bear hugs.

While it's unusual to find an autistic person who is obviously physically disabled as a result of the disorder, most autistic people do have some level of fine and gross motor difficulty. This often manifests itself in poor handwriting, difficulty with athletic coordination, etc. As a result, when autistic people get involved with sports, it's usually in individual, endurance sports such as running and swimming.

Personality Differences

While autistic people do differ from one another radically, it is fairly typical for people on the spectrum to:

Engage in repetitive behaviors and ritualized activities, ranging from lining up items to following a rigid routine,

Have one or a few passionate interests,

Have difficulty in making and keeping multiple friends,

Prefer activities that require relatively little verbal interaction.

It also seems to be the case — for as-yet-undetermined reasons — that certain interests are of particular interest to many people on the autism spectrum. For example, an enormous number of young children with ASD's are fascinated by trains (and the Thomas the Tank Engine toy), while a great many older children and adults on the spectrum are interested in computers, science, technology, and animals.

What Do Autistic People Have in Common?

While people with autism may be very different from each other, they do have certain challenges and traits in common. Of course, it's always possible that you'll meet an autistic person who doesn't fit the mold - but overall, autism implies an impaired ability to read and manage social cues. Autistic people are unlikely to be the life of the party, though they may well be quite talented in such areas as engineering, technology and music. It's important to know that stereotypes of autistic people as "idiot savants" (such as the character presented by Dustin Hoffman in the movie "Rainman") may represent a few unusual individuals, but these are by no means typical of all people on the autism spectrum.

Early Signs of Autism

What are the early signs of autism? As many as six in 1,000 children may be autistic. Is your child one of them? Many parents are worried, in part because autism is so much in the headlines these days. It's a good idea to keep a weather eye on your young child, because even very young children can be diagnosed. And research shows that the earlier the diagnosis and treatment, the better the prognosis for good outcomes.

So what should you be looking for? According to the National Institute of Mental Health, these are some of the red flags for autism:

Possible Indicators of Autism Spectrum Disorders

Does not babble, point, or make meaningful gestures by 1 year of age
Does not speak one word by 16 months
Does not combine two words by 2 years
Does not respond to name
Loses language or social skills
Poor eye contact
Doesn't seem to know how to play with toys
Excessively lines up toys or other objects
Is attached to one particular toy or object
Doesn't smile
At times seems to be hearing impaired

It's important to remember that there are many possible explanations for most of the symptoms listed above. A child's attachment to a particular toy or difficulty with language skills is not, in itself, a sign of autism.

It's also important to remember that a child who does have excellent language skills may still be diagnosable on the autism spectrum. In fact, some children who are diagnosed with Asperger Syndrome have extraordinary language and reading skills.