What Is Applied Behavior Analysis?

Receiving an autism diagnosis for your child can leave any parent overwhelmed. There seem to be a vast number of treatments available — from aggressive dietary restrictions to music therapy. It’s hard to know what will help your child and what is going to be a waste of crucial time and money. But the evidence-based therapy most widely accepted is Applied Behavior Analysis, better known as ABA.

ABA has been shown to help autistic children develop needed skills and minimize undesired behaviors such as self-injury, and it has been shown to be successful for kids all across the autism spectrum, from mild to severe. Its effectiveness is backed up by hundreds of studies.

But ABA itself is confusing because it can take many forms. What they have in common, explains Susan Epstein, PhD, a clinical neuropsychologist, is that “they are based on a simple concept: Behaviors that are reinforced will increase; behaviors that are not reinforced will reduce and eventually disappear.”

The earliest form of ABA, called Discrete Trial Training (DTT), was the work of Dr. O. Ivaar Lovaas in the 1960s. It was extremely structured, breaking down skills and behaviors desirable for children to learn into small, “discrete” components. A child would be led through an activity designed to teach each component, repeating the activity exactly the same way many times, earning a reward for each successful completion and, in some cases, punishment for unwanted behavior. Training was done as many as 40 hours a week.

In the ensuing decades, DTT has been updated and other forms of ABA have been developed that involve “incidental teaching” — helping children learn in the context of play or other activities that would normally be part of their day.

“The idea is to take advantage of something that the child is doing anyway, rather than making them sit at a table and put their feet flat on the floor and their hands in their lap, and asking them to put a piece shaped like a triangle in a puzzle,” says Catherine Lord, PhD, a professor at the School of Medicine at UCLA and a Senior Research Scientist in the Semel Institute for Neuroscience and Human Behavior. “If you’re playing, then they’re more likely to keep learning this and remember it and want to do it again.”

With the newer approaches, not every learning activity needs to be preplanned by the clinician. Dr. Lord gives an example: “If we went to the bathroom and the child pressed a towel dispenser and the towel came out and he was excited, then I could encourage him to press it again to get the towel the next time, and have him learn to get the towel for himself. That teaching is incidental in the sense that I didn’t plan, originally, to go into the bathroom and have him press it, and do that 20 times.”

ABA practitioners now have a range of techniques to choose from or to combine in their work with children. Here is a breakdown of the major teaching strategies that fall under the ABA umbrella. 

Discrete Trial Training, the original “brand” of ABA designed for young children on the spectrum, remains the most structured form of ABA. It is always done one-on-one. The child sits at a table, and the therapist lays out materials in front of the child. The child is given a task to perform with the material — e.g., picking the triangle, or saying the sound “ba” — and when he does it right, he is rewarded with what’s called a “primary reinforce”: an M&M or a Frito, a tickle, a sticker, access to a favorite toy, etc. Punishment is no longer considered an acceptable tool in DTT.

These discrete trials are repeated a set number of times. “When we first did this it was always 20, no matter what we were doing,” Dr. Lord recalls. And the child was expected to do what was asked within three seconds of being presented with the material, she adds. If he didn’t, it would be presented again, or he would be prompted again, to complete the task and get the reward.

“It’s very repetitious,” she adds, “but very, very clearly defined, and all defined by the examiner, so you can get absolutely accurate data through DTT.”

Pivotal Response Treatment, which was developed by Laura Schreibman and Robert and Lynn Koegel, psychologists at the University of California, Santa Barbara, moves beyond the strict task-oriented instruction. “PRT is intended to be more driven by the child, rather than structured more by the therapist,” says Dr. Epstein. “Rather than focusing on individual behaviors, PRT looks to target ‘pivotal’ developmental functions. Natural forms of reinforcement related to the behavior are stressed, rather than non-related tangible rewards, such as an M&M.”

The concept is that if you build these learning modules into a more natural environment, the child is more likely to generalize them, Dr. Lord says. And the focus is on teaching behaviors that are pivotal: That is, they could lead to other breakthrough behaviors.

“You might work on behaviors like looking at me, or imitating, or handing somebody something, or something that was more fun or socially relevant,” Dr. Lord adds. “These behaviors might result in something else happening — start a cascade.”

With PRT the therapist is supposed to follow the child’s lead, not starting the activity until the child engages with something. But the therapist still has skills in mind she wants the child to learn.

Dr. Lord explains: “If I’m doing PRT with a child who’s going to kindergarten next year, I might be thinking, I want this child to learn his letters. So I might lay out things around the room I think he might be interested in that have letters in them, like blocks that have letters or animals that represent different letters. And I lay them out so they look fun. And then I say to him, ‘Hey, what do you want to do?’ I might even say, ‘Do you want to do the blocks or the animals?’ Or I might just let him loose. So I give him a choice and I basically don’t try to teach him unless I’m pretty sure I’ve got his attention.”

A reward that’s related to the behavior, rather than food, she adds, might be letting the child knock down the blocks, if he enjoys that.

The Early Start Denver Model is a newer form of ABA that can be done in individual or group sessions. Developed by psychologists Sally Rogers and Geraldine Dawson, it involves creating activities that are play-based, like PRT, but the therapist also incorporates more traditional ABA if needed. “If the child is so unfocused that he just can’t get started, you can have the child sit in a chair and you just really get him more structured,” Dr. Lord says.

In ESDM you have multiple goals within an activity. Take the example of putting the triangle in the puzzle. “In DTT,” she explains, “I would have one puzzle and I would want the kid to put the triangle in, and I would only teach that triangle with one puzzle. In PRT, I might do that with two different puzzles. In ESDM, one goal might still be for the child to learn the triangle. But I might also have goals for this child to have the motor coordination to get a piece into a puzzle, and to have the patience to finish something that involves three parts. Another goal might be to have him ask me to give him something that he can’t reach. And then another goal might be to differentiate size in the pieces.”

Having different goals within one activity can be pretty challenging for the therapist, Dr. Lord notes, “but you can get a whole lot more done if you get good at this. And you start realizing, Wow, when I do this, I can be thinking about a whole lot of things; I don’t have to just be thinking about, you know, getting that triangle into the puzzle.”