Individuals with ASD show a lack of appreciation of the functions and pleasures of social communication. Even those who have a lot speech generally talk ‘at’ others rather than talking with others.

- Lack of understanding of language as a tool for conveying social and emotional information to others. They may be able to ask for their own needs but find it difficult to talk about feelings or thoughts and to understand the emotions, ideas and beliefs of others.

- Poor comprehension of the information conveyed in body language, eg gestures, facial expression, posture, tone of voice, etc. Hence, they generally do not gesture, mime or use tone of voice, etc. to convey information. Some more able individuals do use gestures but these tend to be odd and inappropriate.

- Those with good vocabularies generally show only a literal understanding of the language, and are unable to pick up the subtle meanings in language. The subjects that they talk about are often limited to a few pet interests. They are verbal autistic people who are fascinated with words but generally do not employ them for social interaction or conversation.