I think my son's misinterpretations tend to be along the lines of assuming other people have some negative or hostile intent toward him. So he'll think someone is angry with him or doesn't like him.

It also seems like he gets angry easily because of misinterpretations of others' actions. Sometimes I wonder, though, which comes first - the anger or the misinterpretation.

It's interesting you mention autism. I've been reading a book called The Interpretation of Schizophrenia from the 1970's by a psychiatrist named Silvano Arieti. He had many years of experience working with patients in psychosis - much of it before psychotropic meds were available. He gives detailed descriptions of people with schizophrenia that he worked with over the years. He uses the word "autistic" to describe some advanced cases. He's not using it in the sense of the childhood disorder but to describe a person who is turned inward toward a fantasy world and failing to communicate with other people or engage with the outside world.

Also I remember talking to a psychologist when I was in the process of adopting. In my home study I said that I didn't want to adopt a child with psychosis. I was thinking of something like schizophrenia. This psychologist told me that when she speaks of psychosis in children, she means autism not schizophrenia. In fact she said sz in childhood is very rare.

So I'd say the two things are related. They both involve turning inward and failing to engage with the world.