Defining autism is a difficult task. The condition is a neurological disorder that has significant ramifications on the individual's ability to interact socially and communicate with other people. Autism is the most recognizable of the five pervasive developmental disorders. In order for an individual to be diagnosed with autism, he has to meet certain criteria defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). The individual must display a combination of symptoms from three categories outlined in the DSM IV; social interaction, communication and behavior. Classic traits of autistic disorder include impaired social interaction, lack of eye contact and lack of empathy. Many individuals who have autism never develop language and when they do, it is often restricted. Stereotyped, repetitive movements and preoccupation with certain activities or objects are also indicative to the autism spectrum of disorders.