I'm in a very similar place to open, somany and *Branleuse" in that I would say "it depends". I think a lot of damaging ABA is done, but I don't think ABA has to be damaging.
There are plenty of adults who went through ABA who see their ABA as abuse, so I think it's not right to just write it all off as "high functioning autistics don't know what they're talking about", which I often see. And some people do run ABA with a normalising agenda (supressing stims, extinguishing behaviour rather than understanding what stresses might be underlying it and minimising those, etc.) I think perspectives of adults who feel they've been damaged by it are incredibly valuable to parents, as it allows you to really think about whatever interventions you are doing (way beyond ABA - I remember also being very distressed by DD's physio in the past and not at all sure if we were doing the right thing) and whether they might be damaging (even if they are also helpful in other ways).
On the other hand I think a knee-jerk rejection of behavioural approaches is also overdone. All parents and teachers use behaviouralism to teach their kids (a tick in a homework book, a star chart for good behaviour, saying "well done", smiling, detentions, is all behaviouralism). Most of us even do behaviouralism on ourselves (I have a Fitbit, and treat myself to a coffee on the days I walk to work, promise myself a tea and a biscuit when I've finished an unpleasant task, and a drink in the evening when I've had a constructive day at work).
We ended up getting some ABA support and using some ABA approaches (and like open we're lucky that DD is verbal and pretty happy so it makes a lot of these questions easier or less pressing: I'm aware that's a privileged position).
On that basis I would propose some "obviously fine" and "obviously not fine" buckets:
- A lot of it was a bit like the physio my daughter had when she was late to walk: taking things that she wanted to do but couldn't work out (like talk to another child) and breaking them down into tiny steps that she could practice and build on. I really struggle to see a problem with that. A lot of our kids (probably all??) do want to communicate, they just don't know how - so breaking down that communication into smaller steps that might be more manageable can't be a bad thing.
- I have never heard of a good argument to use behaviouralism to reduce stims or other coping behaviour or to increase eye contact (or anything else designed to increase the comfort of the people around the autistic person, rather than the person themselves). Even things like showing distress/shouting have an underlying cause: if you just extinguish the behaviour the danger is the cause is still there and the child is struggling and actually becoming less able to communicate because they are being incentivised not to communicate in the ways they know how. But I think many ABA practitioners are probably aware of this and try to understand the sensory triggers and redirect self-harming stims, rather than extinguishing them.
I have also read suggestions that ABA is too focused on verbal communication, and therefore misses opportunities to get kids communicating in other ways (if you look up Nurturing Neurodiversity, her non-verbal son is doing amazingly with an AAC app on her iPad: as far as I'm aware nobody in the UK is funding that or helping parents learn how to use it, or helping parents access funding to provide it if they can't afford it, and personally I'd put budget there before ABA).
I do also think the risks of "over-compliance" (and therefore the risk that children wouldn't e.g. report abuse) are worth bearing in mind. Of course this is also true of children being expected to be compliant in any setting (schools, etc.) and we know it isn't only autistic children who are abused and say nothing: but certainly something to be aware of if they are being rewarded for doing what an adult tells them even when it's unpleasant/distressing to them.
Finally, as
somany says, I think it's important that the activities themselves are motivating and fun. I'd be very worried if my child was doing something in order to access food or a favourite toy for example. But then, if a few sweets was what it took to induce my child to learn to look after their bathroom needs independently (increasing their independence and reducing their vulnerability long term), would I do it? Probably. So there is plenty of "grey area" between the "obviously fine" and "obviously problematic".
The problem is no parent knows what their child would or wouldn't have done if they had/hadn't had ABA (would they have been verbal or not? Would they have been more or less anxious?) And the evidence base is largely old and a lot of it was on "appearances" (so it was in those days trying to normalise). I'd be very interested in research that linked ABA to later mental health for example (I can see arguments why it could go either way) - but you'd have to very carefully define what ABA actually is and what targets were being pursued and how, as currently ABA seems to be almost any behavioural intervention (and actually lots of the things our consultant suggested - like doing a diary with DD to encourage her to process things that had gone well and badly during the day - were not really behavioural at all).