by Nancy Langdon, PhD, BCBA-D
It wasn’t what he said-- it was the way he said it. “He WANTS to go for a walk!!” A seemingly innocuous request, but those of us who worked with him regularly knew what this meant-- we knew it was different from “Go for a walk please.” When the emphasis was on the word “WANTS,” and he referred to himself in the third person, Randy was getting ready for a violent burst of self-injury. And it wasn’t a walk he wanted-- it was a break from his schoolwork. We all knew that what we did next would determine the course of the next hour-- and could result in a ninety minute tantrum where Randy scratched his face until it bled, ripped out clumps of his hair, and bit his arms and hands.
Randy had precursor behavior. Precursor behaviors are innocuous behaviors
that reliably precede the occurrence of problem behavior. They act as “warning
signs” that problem behavior is going to occur. Precursor behaviors fall into different topographies, including verbalizations, movements, and non-compliance. Many clients have precursor behaviors-- as clinicians, we have to recognize them and respond appropriately.
As behavior analysts, we are taught to focus on motivating operations,
antecedents, behaviors, and consequences. Precursor behavior is often
overlooked. Yet most clinicians will agree that there are times you “know” to tread carefully. Is there something you can identify that is a valid, reliable indicator that problem behavior is likely? Why should you care?
Research has shown that precursor behavior serves the same function of problem behavior. This means these behaviors are members of the same response class. To return to Randy, “He WANTS to go for a walk” served the same function as his self-injurious behavior.
Different methods can be used to identify potential precursor behaviors. Simply stated, any method you use to select your problem behavior can be used to identify precursor behavior too. For example, you can interview parents or teachers and ask if the student has warning signs they are going to have problem
behavior. Likewise, you can observe in the classroom or home setting-- does the child do something specific before problem behavior? Do adults act in a certain way to prevent problem behavior from occurring? Precursor behavior can be operationalized just as problem behavior and should be as specific as possible. For Randy, it wasn’t just “asking to go for a walk.” It was “demanding a walk referring to himself in the third person.”
Once you have operationally defined a potential precursor behavior, you need to determine that it regularly occurs before problem behavior. You can do this through observations-- either informally or by calculating transitional probabilities. Specifically, there are calculations of interest: how often does precursor behavior
lead to problem behavior? How often does precursor behavior lead to another precursor behavior? How often does precursor behavior lead to “other”? How often does problem behavior lead to another problem behavior? This information can be used to mathematically demonstrate that a precursor behavior is, in fact,
a precursor behavior.
So you’ve identified a precursor behavior. What now? There are implications for prevention, assessment,
● Prevention: Efforts can be applied to precursor behavior to prevent an escalation to problem behavior.
For example, training Randy to ask for a break when “he WANTS to go for a walk” will likely prevent
the occurrence of problem behavior.
●Assessment: A functional analysis or experimental manipulation can use precursor behavior as the dependent variable instead of problem behavior. For example, in a typical FBA demand session, the 30s escape can follow the precursor behavior instead of problem behavior. This addresses the often-cited ethical criticism that functional analysis shapes problem behavior. A manipulation of antecedents and consequences of precursor behavior gathers the same information with less risk.
For a demand session with Randy, a 30s escape would follow “he WANTS to go for a walk.”
● Intervention: Typical functional communication training relies on situational determinants to prompt communication-- teaching “break” in response to a demand. Using precursor behavior focuses the effort on the student-- teaching “break” in response to the student indicating the need for one. For Randy, this would mean prompting a break request when he says “he WANTS to go for a walk”
instead of when issuing a demand.
The individuals we work with will display problem behavior-- a better understanding of precursor behavior can help you to reduce its occurrence-- or prevent it altogether.
Langdon N.A.,Carr E.G., & Owen-Deschryver J.S. (2008). Functional analysis of precursors for serious problem behavior and related intervention. Behavior Modification, 32: 804-27.
Smith, R.G., & Churchill, R.M. (2002). Identification of environmental determinants of behavior disorders rhrough functional analysis of precursor behaviors. Journal of Applied Behavior Analysis, 35, 125-136.