You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is The following are characteristic of autism, EXCEPT: and explain in detail?
The onset of autistic disorder always occurs before age 3, at two peak periods. Autistic disorders are characterized by the triad of impaired social interaction, communication and imagination. These are associated with rigid repetitive pattern of behaviour. Ref: Essential Pediatrics By O P Ghai, 6th Edition, Page 65; Autism: A Very Sho Introduction By Uta Frith, 2008, Preview.