And as for looking at other causes, in France (as it sometimes does here) that translates into "so, how can we blame the mother for this?"
Did you know mothers of autistic children who are autistic themselves are often accused of having a "lack of affect" and of lacking a "proper bond with their child?" And sometimes are outright accused of making up their child's issues, because an autistic parent will naturally know a lot about autism, something professionals interpret as an obsession with the subject and wanting the child to have it.
You know why that is? Because the so called professionals who are supposed to be experts in autism can't recognise those traits in women.
Like this scenario from the guardian article I linked to:
"A consultant psychiatrist said Rachel was fabricating her children’s symptoms for attention, that they were not autistic, and that she wanted them to have autism spectrum disorder in order to make herself look more interesting.
Rachel’s children were taken and placed in care homes.
The children were subsequently diagnosed with autism and other issues, proving Rachel right. But despite a high-profile court battle in which parents’ groups denounced the “prehistoric vision of autism in France”, Rachel, who herself has Asperger syndrome, has still not won back custody of her children two years later. They remain in care with limited visiting rights. Local authorities insist the decision was correct. "
And for what it's worth, no I don't think autism is over diagnosed in this country. Given how difficult it can be just to get a child assessed, the stereotypes and myths that still remain entrenched amongst medical professionals and the long wait to get a diagnosis - I really don't see how it could be an issue. I think there's a huge problem with girls going undiagnosed, and academically able kids with autism getting left to flounder because some professionals seem to think as long as they are "ok in school" (And by ok I mean they aren't misbehaving) that they don't need a diagnosis. It's really common for kids like that to fall apart in secondary school and their parents are left scrambling trying to pick up the pieces in time for their GCSEs, which is unlikely given that in most places the list for assessment can run anywhere between one and three years.
I do however find it amusing (and frustrating) that you used France as an example of a country that diagnoses less kids with autism, whilst you a) had no clue why that was, b) had no idea that France still relies on such outdated views as blaming the mother, and then c) went on to say "maybe that raises the question of whether or not we over diagnose autism in the UK."
The only question France's autism practices raise is "how can a country that's a member of the EU and a signatory of the human rights convention be allowed to get away with treating disabled people in such a disgusting manner and depriving them of their rights."