[header] How to communicate with a mentally challenged person [title] Don't assume that someone has an intellectual disability based on the ease of their speech. [step] Some people who have difficulty speaking, such as people with cerebral palsy and some autistic people, are on average just as smart as anyone else. A disability accent, slow speech, or halting speech doesn't always mean an intellectual disability. 
[substeps] People who can't speak can be of any intelligence level. Body language does not relate to intelligence either.