Differential diagnosis:

• Difficulty in forming friendships
• A preference for playing alone and not with peers
• No empathy with friends or family
• Ability to talk well, either too much or too little, but difficulty with communication
• Inability to understand that communication involves listening as well as talking
• Inability to understand the rules of social behaviour
• Having trouble accepting conventional social rules
• Dislike any change in setting or routine
  
• Anger and aggression when things do not happen as they want
• Prone to depression
  
• Sensitivity to criticism
• A narrow field of interests
• Fascinated by particular inanimate objects
  
• Eccentricity
• Normal or higher than average intelligence
• Single-mindedness
• Extensive vocabulary
• Expertise in their chosen topic of interest
• Excellent factual memory for their chosen topic of interest
• Dedication and commitment to their job if they work in a supportive environment and their job is suited to their interests
• The drive to perform well at school or work, if given a supportive and inclusive environment