By now I'm sure you've heard the new "1 in 50" CDC prevalence numbers for autism [link to Emily Willingham's excellent Forbes.com article]. What these numbers demonstrate is that under-diagnosis is the issue, rather than a significant increase in autism rates. And for those of you Silicon Valley locals who are thinking, "well, I didn't see these kids in my class when I was growing up," read on.
Anecdotes and personal experience are a good starting point for thinking about an issue, but when we're talking about a population it's important to look to the numbers over time, along with diagnostic criteria changes. Thirty years ago in the US, there was no such thing as an Asperger's diagnosis -- that wasn't part of the DSM until 1994.
We also need to consider that Silicon Valley is a different place than where many of us grew up. There are just more autistic kids here. And that's not surprising, given the increasing evidence that autism can have a significant genetic factor, and given how still-uncommon it is for any adult with Asperger's over 30 (i.e., many of our local engineers and scientists and innovators) to be diagnosed.
Most of the kids making up the new numbers can "pass" and so have been overlooked. Not all. Most. These kids may not need as much support as their more intensely autistic counterparts, but they do deserve accommodation so they can succeed both academically and emotionally.
The problem is that these kids have historically been more difficult to identify, and this slipperiness is part of the basis for the new DSM-5 diagnosis changes. "Passing" is especially true for autistic/Asperger's girls, who tend (though not always, mind you) to be rule followers and are often considered "good kids" by adults even as they struggle socially with their peers.
I'd recommend reading IACC member Matt Carey's post on the new numbers. He breaks down many of the factors that concern us all. Specifically:
"We (a society of autistic and non-autistic people) need to give autistics the tools and supports needed to succeed in this world, with various definitions of success. And we can’t do that if we don’t understand what is needed. 2% is a number that can grab people’s attention."From: http://leftbrainrightbrain.co.uk/2013/03/25/autism-rate-2-what-now/
Warm regards. I'm off to hunt Easter Eggs with my kids. Leo's going to love it.