Yes, of course they do. What they laugh at or what they think is funny may surprise you because it’s never the same as what the average child may laugh at or think is funny. A high functioning child with autism can laugh at simple jokes but won’t understand jokes that are a play on words or require a point of reference in order for the joke to be funny. The problems they have understanding certain aspects of descriptive language and its lack of being more concrete means that a lot of jokes just won’t make sense to them.
Lower functioning children with autism have an inner dialogue about things that parents and the other people in their lives aren’t privy to. These inner dialogues of theirs cause them to laugh about a toy, and event where laughter is inappropriate, or laugh at the antics of the family dog who’s just rolling around on the floor. There’s not much rhyme or reason to what this group laughs about, but there’s also no harm in laughing with them because you can only imagine what it is they think is so funny.
Children formerly diagnosed with Asperger’s who will be recategorized as high functioning autistics in 2013, rarely laugh or laugh at things that are completely inappropriate to laugh at. In this subset of autism, children can be a little frightening to parent s and peers because they laugh at really cruel and unpleasant things. Behavioral therapy sessions can correct this type of inappropriate sense of humor.
Good or bad, all children with autism laugh unless they are so low functioning they are catatonic, in which case it would be really difficult to tell if they are autistic or not. No matter where your child is at on the spectrum, as long as they aren’t laughing about carnage, feel free to laugh with them. It’s one of the most pleasant and surprising moments when the children pause in their laughter to notice you are laughing too.