DS has AS. He's very chatty with us, well he talks at us about his interests and asks constant questions.
He rarely speaks to people he doesn't know or doesn't know well. He won't speak in front of the class but chats to his friends quite happily.
He had a supply teacher he'd never seen before and wouldn't answer his name at registration and he only speaks to the teachers if they ask him a question in the lesson.
I've witnessed him totally ignoring the senco in meetings, even when asked questions he just nodded his head. Everyday she says good morning to him and he ignores her.
Is this selective mutism? My FIL thinks it's rudeness but I disagree.