People who have rare developmental disabilities are often misdiagnosed with autism. This happens in part because a lot of disabilities look similar in early childhood. When kids with undetected rare genetic conditions start ‘missing milestones’, they are often assumed to be autistic.
When people are assumed to be autistic, autism stereotypes get applied to them. They’re often assumed to be uninterested in people and communication, and they’re often put into ABA programs prescribed for autistic people. They face the same kind of degrading and damaging misunderstanding that autistic people do.
When advocacy organizations address the issue of misdiagnosis, they tend to say some form of “It’s important to distinguish between autism and Not Autism Syndrome, because demeaning autism stereotypes only accurately describe autistic people.”
Here’s a Rett Syndrome example: “The child with RTT almost always prefers people to objects, but the opposite is seen in autism. Unlike those with autism, the RTT child often enjoys affection.”
And a Williams Syndrome example:
“Unlike other disorders that can make it difficult to interact meaningfully with your child, children with Williams Syndrome are sociable, friendly and endearing. Most children with this condition have very outgoing and engaging personalities and tend to take an extreme interest in other people.”
Statements like these suggest that the problem with autism stereotypes is that they're applied to the wrong people. The thing is, demeaning autism stereotypes *aren’t true of anyone. We all have feelings and thoughts and the capacity to care about things and relate to other people. Accurate diagnosis matters, but not as a way of sorting out who is and isn't fully human. We're all fully human, and no one should be treated the way autistic people are treated. We shouldn't pass around stereotypes, we should reject them.