A short spoken explanation (YouTube transcript) by Ming @ Agents of Speech discussing whether speech/language delay and autism are distinct. The speaker states they can co-occur, notes that causes of speech/language delay are largely unknown (80–90% unexplained), and discusses both biological predispositions and environmental factors; autistic children may show reduced social motivation which can affect language development.
Is it speech delay or speech language delay and autism are separate? No, it can happen together. At this point, we do not know most of the 80 or 90% of the reasons why a child is delayed in speech and language. A child can have very good motor skills, very good play skills, but they will still be delayed in language. We still don't know why. There are nature and nurture. There are predisposed reasons. There are environmental reasons as well, meaning maybe the language environment is not as rich. There aren't as many kids to play with them, they aren't exposed to as many language models as they should be. And same goes to autism. As a developmental disorder, you have it by birth and you cannot develop it. Autistic children or people, they do not really want to socialize and therefore, if they don't use language, therefore their language doesn't catch up to their peers. So if you're comparing autistic children or people to the norm of the society, obviously they're not going to be as good as language if they don't enjoy it and like it.
