People with disabilities are capable of learning things on purpose, because they’re interested in what they’re learning. That’s true of people with all kinds and degrees of disability. Everyone cares about things, everyone thinks, any everyone learns.
And yet, education for people with disabilities often starts from the assumption that disabled folks have no intrinsic motivation to learn. That, before you can start to teach anything, you have to identify a reinforcer for the target behavior. And that it should be the same across subjects, and that it needn’t have any relation to what you’re trying to teach.
So, instead of starting by teaching reading, you might start by identifying an effective reinforcer, and using it to reinforce reading behavior. For example, stickers. Or giving a jellybean each time someone reads a page. Or high fives.
In a technical sense, finding a book that someone enjoys is also, according to behaviorist theory, finding an effective reinforcer for reading behavior. But it’s not at all the same as using an unrelated reinforcer to teach reading.
Finding a book that interests a person you’re teaching to read communicates why reading is worthwhile. Using an unrelated reinforcer to get them to cooperate with reading lessons may work, but it doesn’t communicate the value of reading. In fact, it actively demonstrates that you’re assuming that they will not value reading and that it’s not worth trying to convince them that reading is worthwhile.
The same is true of communication lessons. Identifying a reinforcer and using it to reinforce speaking behavior can get someone to cooperate with rote speech lessons, but it can’t teach them what symbolic communication is. Figuring out what someone wants to say, and giving them a reliable way to say it, can. So can making sure that you listen to communication someone already has, and making it clear that you respect them. (If you refuse to learn their language, you’re teaching them that their communication doesn’t matter. Which is the opposite of helpful.) Behaviorist approaches something accomplish that, but only as a side effect. You can teach communication better if you teach it directly, rather than as a side effect of reinforcing speaking or pointing behavior.
People with disabilities care about things, and want to learn. The assumption that we don’t is deeply degrading.