Autism is a developmental disorder characterized by three levels of impairment: verbal/nonverbal communication, social interaction, and imagination. While symptoms can range in severity, individuals with autism may display tics and repetitive behaviors, obsessions with specific interests, difficulty with social interactions and communication, learning or speech disabilities, lack of awareness of social cues and other people’s emotions, sensitivity to sound, touch, or other senses, and more. Sacks is specifically interested in learning what the inner world of an autistic person truly looks like. Both Stephen Wiltshire (“Prodigies”) and Temple Grandin (“An Anthropologist on Mars”) have been diagnosed with autism. Autism may also be referred to as “autism spectrum disorder.”

Asperger’s syndrome is an autism spectrum disorder. Asperger’s differs from other forms of autism in the patients’ ability to utilize language effectively and in their lack of learning disabilities. Patients typically struggle with social cues and nonverbal communication. Grandin may have Asperger’s syndrome as opposed to the classical autism that Stephen displays, although as a child her symptoms had more in common with the latter.