Originally posted by: Modelworks
My sister is mentally retarded. She is 40 now and on the level mentally of about a 12 year old.
You treat him just like you would anyone else. Their mental level may be lower but that doesn't mean you have to be scared or cautious or act like they are someone you have to be careful what you say around. They may have a lower IQ but you may find they have much more to offer in other areas. My sister for instance cannot see bad in anyone, she always sees the good. Someone can yell at her and while she may cry from the experience, if you ask her an hour later about the person, she will say something like "Thats ok, she just cares a lot" . And when she says that she isn't saying it to just blow off the experience, she really means it.
The big thing to remember is they do not want to be treated any differently than anyone else, that to them is the worst insult.