I really think that my son is becoming more aggressive physically and verbally since starting therapy.
In our son's ABA program we have documentation of what's getting worse and better; a daily log of behaviors such as tantrums, and daily notes from the tutors. Of course as parents we have to do our part to put the data in the log (which we've been better at some months than others). Anyway so there should be some hard numbers about whether stuff is getting worse, if not I'd ask the team to start keeping track.
I wrote down a longer answer about how things work in our program on this question: http://www.myautismteam.com/questions/5330eb440...
It is possible that things getting worse are an extinction burst; it's possible that someone - you or the tutors/parapros or analyst - should be doing something differently; it's possible that the function of the aggressive behavior has been incorrectly identified so the whole approach is wrong; it's possible that there are unrelated stress factors affecting your son (hunger, pain, sleep, routine).
The ABA stuff is not a brainless process; everyone has to trouble-shoot and problem-solve and try to get it right. We have had some tutors who were better than others and we've also had some areas where we were better able to be consistent parents and some that were hard for us. If an approach is not working, that should be visible in the data and the team should try to find the problem and make a change.
However when we've 1) correctly determined the purpose of a behavior that won't serve our son well, and 2) taught a better alternative, and 3) been truly firm and consistent about not reinforcing the poor behavior, we've seen amazing results and he's learned the better alternative and stuck to it.
But like anyone, kids are human too - sleep, changes in routine, food, headache, sensory stuff, weather, all these variables do affect everyone. So day-to-day our son might have a harder time or an easier time. We aren't trying to make him "perfect." Knowing appropriate ways to get needs and desires met certainly improves his day on average though. Long tantrums and such aren't fun for the child either.
It is not unusual to see an increase in challenging behaviours at the onset of any sort of therapy or intervention. After all, it is something new, an increase in demands, a change in routine and a different set of expectations. However, you have not indicated when you started ABA. A good ABA provider should be able to assess a situation and make adjustments as needed.
Many parents have issues with ABA because there way of dealing with the situation is not to avoid but to make the child adapt and cope with things they do not want to do. We as parents tend to avoid the meltdowns and tantrums by giving in to the child, but the problem is the child picks up on this and uses it. This situation is not good because the child never learns to act appropriately and when they get bigger and stronger they are harder to handle.
Many parents make the mistake of giving in but you are not helping your child in doing that, they need to learn to cope because in the real world you cannot always get your way. That being said a good ABA knows where to draw the line and only push the child so far.
What you will most often notice is that if you leave the area and stay out if view of the child and let the therapist work you will start to notice the child will respond but the minute you are back in the picture the child acts out. This is because they know you will give in and let them do what they want. The same thing happens at school sometimes, the child does what they have to do without issue but if you try the exact same thing they give you a hard time because again they know how to work you.
All behaviour is communication. In the absence of effective communication and/or appropriate coping skills, a child may act out in an attempt to make their needs known.
Some behaviours are attention-seeking. Any reaction (even a reprimand) would actually reinforce that behaviour to continue even if it seems counter-intuitive. But, other behaviours serve another function or reason (i.e. avoidance of demand/situation, desire to obtain preferred tangible, fulfill sensory need, etc). What intervention is to be used depends on what function the behaviour is attempting to fulfill.
If a particular intervention doesn't seem to be working, then the ABA provider should re-examine the function of the behaviour.
Good ABA providers implement a parent training component. It is important that parents (and caregivers) understand the functions of behaviour and learn strategies to implement outside of session to ensure consistency and generalization of skills.