There are, at present, five distinct Types Of Autism within the autism spectrum. These five types are:
- classic Autism
- Asperger Syndrome
- Pervasive Developmental Disorder (PPD-NOS)
- Rett Syndrome
- Childhood Disintegrative Disorder
If you feel that you or someone you love may exhibit traits of a disorder on the autism spectrum, the Autism Spectrum Quotient (AQ) test is a well-respected, easily-accessible starting point. 
It’s essential to note that, as Dr. Jill Stansbury writes at LiveStrong.com, in her article “Different Types Of Autism”: “IQ [of a person with an autism spectrum disorder] may be low, normal or above average. The terms “high” and “low” functioning…refer to how capable an individual is able to speak and care for themselves. Some autistics with a high IQ may display a profound inability to carry out the simplest tasks of daily living.”
The five Types Of Autism share certain characteristics in common, yet there are distinct differences between them as well. Read on for a brief listing of attributes for each of the five Types Of Autism:
- Classic Autism: symptoms exhibited at age two or three; presents as language delay, disinterest in socialization, with repetitive behaviors; regressive (learned skills seem to disappear)
- Asperger Syndrome: socialization and interactive difficulties, usually becoming apparent at age four or five (including difficulty reciprocating in conversation, facilitating peer relationships, making appropriate facial expressions, eye contact, gestures); lack of language delay; high IQ
- Pervasive Developmental Disorder (PDD-NOS): diagnosed when other categories within the autism spectrum aren’t a good fit, but challenges are apparent. It is closest to classic Autism in terms of behavior and presentation. Common signs include: communication delays; withdrawal or difficulty with socialization; repetitive behaviors; extreme dislike of changes in routine.
- Rett Syndrome: is more common in females than males (unlike other disorders on the autism spectrum); regressive; growth of head slows down (circumference is normal as an infant and toddler, then stops growing); repetitive moments; lack of coordination.
- Childhood Disintegrative Disorder: appears prior to age 10; regressive, like classic autism; shows delays and difficulties in bladder control/use of bathroom, friendly and appropriate socialization and play, motor skills.
Though each of the five Types Of Autism presents its own challenges for individuals and their families, receiving a diagnosis of an autism spectrum disorder does not suggest that one lacks gifts, or that one has no contribution to make. On the contrary, persons with autistic traits have made (and continue to make) major contributions to humanity. As Temple Grandin, Ph.D (see Famous People With Autism), writes in her classic Thinking In Pictures, “In an ideal world the scientist should find a method to prevent the most severe forms of autism but allow the milder forms to survive. After all, the really social people did not invent the first stone spear. It was probably invented by an Aspie [person with Asperger Syndrome] who chipped away at rocks while the other people socialized around the campfire. Without autism traits, we might still be living in caves.”