I think most people would say that autism involves the triad of impairments of communication, social behaviour and repetitive behaviour, but is also very much a syndrome with a huge range of manifestations. My grandson is considered atypical because he likes to try and make friends, but lacks the skills to do so. I also think that his development is complicated by bilingualism (they are a bilingual family and you can't change that), but I can't find much research on the impact of that. My DiL went to a lecture recently where they said they are looking at the impact of stress hormones in the womb, as well as the genetic component. They also said that they think it is much more common in girls than was previously thought, but it often goes undiagnosed.
I agree, Mishap, I wasn't at all sure about the two little boys at the end of the programme, but I guess it is hard to see the whole picture from the bit we were shown.
In terms of how it is dealt with in society, my grandson gets no support at all in school in Spain, despite having an official diagnosis from the psychiatrists and neurologists in the local hospital. He has a private therapist who is very good, though.