Stimulus Preference Is Not Stimulus Function

By Shelley McLean, M.Ed, BCBA

bSci21 Contributing Writer

The phrase, “It is what it is,” seems to be increasingly popular in daily conversation, which may not be surprising, since it seems to apply in a multitude of situations.  It strikes me, however, that perhaps behavior analysts should lay claim to our own version of this phrase; instead of “It is what it is,” a more accurate, although equally grammatically awkward expression might be, “It is how it functions.”  Let me explain my thinking . . .

Have you ever worked with a staff member, interventionist, parent, or caregiver on delivering effective reinforcement, and found yourself explaining that just because a learner likes something, that does not necessarily mean that the stimulus will be an effective reinforcer?  While identifying preferred items is certainly a good starting point, as we know, the only way to determine whether or not the stimulus will function as an effective reinforcer is to test its effect on the specific behavior we want to change.  Not only that, but even if the stimulus functions as a reinforcer for one behavior or in one situation, that does not necessarily guarantee that it will be in effective reinforcer in other situations.  “It is how it functions.”

Although the situation with respect to reinforcement is quite common and straightforward, this expression, which I have to admit is starting to grow on me, holds true for many other situations and principles in Applied Behavior Analysis as well.  Think about a situation in which a classroom teacher walks to the front of the classroom and says, “Okay class, take out your math books.”  In most cases, students will follow the instruction, reach into their desks or backpacks, and take out their math books.  However, imagine that one of the students has a less-than-pleasant learning history associated with math, and instead of taking out his math book, he gets up from his desk and runs from the classroom.  What might explain this behavior?

There could be a number of variables at work, but one possibility is that the teacher’s statement, which she intended to function as a discriminative stimulus (SD), may actually be functioning as a conditioned motivating operation (CMO) for the learner who ran from the room.  Jack Michael called this type of a conditioned motivating operation “reflexive,” meaning that it establishes its own removal as reinforcing (Michael, 1993, p. 199).  In this example, it may be that, the teacher’s words, “Take out your math books,” served as a CMO-R for this particular learner, and that by running from the room, the learner was able to remove the threat of a worsening situation.  A very common phrase, regularly emitted by teachers, and generally intended to function as an SD may have operated quite differently in this case.  “It is how it functions.”

In spite of the grammatical shortcomings of the expression I am trying to sell you on, it seems to me that the underlying principle actually holds many parallels to grammar.  I’m probably dating myself here, but I remember sitting in English Language Arts class grammatically analyzing sentence after sentence, trying to identify which individual words functioned as nouns, verbs, adjectives, direct and indirect objects, and so on (my English teacher would be so impressed, not to mention shocked, by the shout out!).  I remember my frustration when, just when I thought I had figured out that every word that ended in “ly” was an adverb, some actually functioned as different parts of speech, depending on how they were used in the sentence.

I’m not suggesting that I want to go back to the days of deconstructing sentences and analyzing parts of speech and grammatical structures (sorry, Miss C.), but I do think it might serve behavior analysts well to think in similar terms when evaluating behavior and the associated contingencies.  We sometimes fall into the trap of making assumptions about what we think a particular variable “is” instead of critically examining its function in each specific situation.  So the next time you hear the phrase, “It is what it is,” I hope you stop and think, “Nope, but it is how it functions!”

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Michael, J. (1993). Establishing operations. The Behavior Analyst, 16(2), 191-206.


smclean-headshotShelley McLean, M.Ed, BCBA is passionate about empowering educators with an understanding of behavioural principles to give them the tools and the confidence to ignite the potential in all of their learners.  She is the Coordinator of the interprovincial Autism in Education (AIE) Partnership for the Atlantic Provinces Special Education Authority (APSEA) in Halifax, Nova Scotia, Canada.  Shelley has worked as a classroom teacher, guidance counselor, high school administrator, itinerant ASD consultant, and provincial Learning Specialist for ASD and Complex Cases during her career in education, which spans more than 17 years.  She has also served as a part-time instructor for ABA courses at the University of New Brunswick and Western University in Ontario.  Shelley holds Bachelor degrees in Arts and Education, and a Master of Education degree in Counseling Psychology.  She completed a Graduate Academic Certificate in Applied Behavior Analysis from the University of North Texas and has been a Board Certified Behavior Analyst (BCBA) since 2010.  You can contact her at [email protected]

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