I've long suspected that I may have some weak form of autism. Autism might have been made famous by the movie Rainman, in which a character has difficulty with social interactions (seeming to some as if he suffered from mental retardation), and yet is highly developped in other mental abilities (able to count the number of toothpicks in a jar after glancing at it for a second). Autism is a spectrum disorder (as opposed to a binary on/off disorder), and the Rainman is the extreme case. There is a theory that "everyone is autist", and it's just a matter where in the spectrum each person lies (though apparently this isn't a popular view in the field). After reading a bit more about it these last few months, I came across something called Asperger's syndrome which is basically weaker version of autism (the people who study the two aren't sure if they are two versions of the same disorder, or two completely different disorders with similar symptoms). Most recently, I've read this book which mentions the Diagnostic and Statistical Manual of Mental Disorders (DSM) as a standard benchmark which psychologists are intended to use to diagnose Pervasive Development Disorders (PDD), a superclass of Autism and Asperger's syndrom which also includes Rett's disorder and childhood disintegrative disorder. According to the DSM-IV, the fourth edition of the manual, I have full blown autism.

The DSM-IV lists twelve symptoms, and states that I need to have at least six of these symptoms to be diagnosed as autistic. Furthermore, I have to experience at least two of the symptoms in the"reciprocal social interaction" domain, at least one in the "communication" domain, and at least one symptom in the "restricted, repetitive behaviors" domain. Furthermore, at least one of the symptoms had to have been present before age three. The symptoms I suffer from are as follows:

• Deficits in reciprocal social interaction
• Difficulty using nonverbal behaviours to regulate social interaction
• Trouble looking others in the eye
• Little use of gestures while speaking
• Failure to develop age-appropriate peer relationships
• Few or no friends
• Relationship only with those much older or younger or with family members
• Relationships based primarily on special interests
• Little sharing of pleasure, achievements, or interests with others
• Enjoys favorite activities alone, without trying to involve other people
• Little interest in or reaction to praise
• Lack of social or emotional reciprocity
• Does not respond to others; "appears deaf"
• Does not notice when others are hurt or upset; does not offer comfort
• Deficits in communication
• Delay in or total lack of development of language
• After speech develops, immature grammar or repeated errors
• Difficulty holding conversations
• Fails to respond to the comments of others; responds only to direct questions
• Difficulty talking about topics not of special interest
• Unusual or repetitive language
• Repeating what others say to them (echolalia)
• Repeating from videos, books, or commercials at inappropriate times or out of context
• Using words or phrases that the patient has made up or that have special meaning only to him/her
• Overly formal, pedantic style of speaking (sounds like a professor or textbook)
• Restricted, repetitive behaviours, interests or activities
• Interests that are narrow in focus, overly intense, and/or unusual
• Very strong focus on particular topics to the exclusion of other topics
• Difficulty "letting go" of special topics or activities
• Interference with other activities (for example, delays eating or toileting due to focus on activity)
• Unreasonable insistence on sameness and following familiar routines
• Easily upset by minor changes in routine
• Need for advanced warning of any changes
• Becomes highly anxious and upset if routines or rituals not followed
• Repetitive motor mannerisms
• Walking and/or running on tiptoe
• Preoccupation with parts of objects
• Uses objects in unusual ways (for example, flicks doll's eyes) rather than as intended.
• Attachment to unusual objects

The list is hiearchal, with the top level being the three domains, the mid level being the actual symptoms I have out of the possible twelve, and the lowest level being examples that the book actually gives that I have experienced. For the "age-appropriate peer relationships", I tend to prefer to befriend people a lot younger than me (e.g. 14 year olds), something I had previously (worriedly) assumed was some sort of pedophilia or something. I'd say the vast majority of people who I'd give the label "friend" are special interests (Bemani).

As for having one of these symptoms before age three, I don't remember anything from that period, so I don't know if I'd really qualify for autistic disorder or not, but aside from the "before age three" thing, it looks like I'd be diagnosed as being austistic.