Translated from the Portuguese original. Read the original (Português)
A motivating operation (MO) is any change in the environment that makes a reinforcer worth more or worth less at that moment — and, at the same time, increases or decreases the frequency of the behaviors that have already produced that reinforcer. Going hours without eating makes food more valuable and makes the person look for food: that is an establishing operation (EO). Leaving the table after a big lunch does the opposite: that is an abolishing operation (AO). The MO does not explain what the person knows how to do; it explains why they do it now.
A motivating operation is an environmental variable that produces two simultaneous effects. The value-altering effect: it increases or decreases the reinforcing (or punishing) effectiveness of some stimulus, object, or event. And the behavior-altering effect: it changes the current frequency of every behavior that has, in the past, been reinforced by that stimulus. When the value goes up, we have an establishing operation (EO), with an evocative effect (more behavior now); when the value goes down, we have an abolishing operation (AO), with an abative effect (less behavior now).
Two effects, always together
It is tempting to think of motivation as something the person “has inside.” Behavior analysis asks a more useful question: what changed in the environment for that reinforcer to become more (or less) important right now? Deprivation, satiation, pain, fatigue, heat, a difficult demand — all of these are observable events that shift the value of consequences.
Notice that the two effects go hand in hand. Going without water all afternoon doesn't just make water “worth more”: it makes you get up, look for the water fountain, ask for a glass — any behavior that has already produced water. After you drink, the value collapses and all of those behaviors disappear for a while.
EO and AO: the two directions of the same variable
Every motivating operation pushes in one direction or the other. Explore both:
Increases the value → evokes the behavior
The EO makes something more reinforcing and, because of that, raises the frequency of every behavior that has already produced it (an evocative effect).
- A poorly slept night increases the value of resting — and the child flops onto the couch, cries more easily, avoids long tasks.
- A noisy room increases the value of silence — and leaving the room becomes a highly desirable consequence.
- Going without attention for a long stretch increases the value of attention — and behaviors that tend to call the adult over show up more often.
Decreases the value → reduces the behavior
The AO makes something less reinforcing and, because of that, lowers the frequency of the behaviors that produced it (an abative effect).
- After playing with the tablet for a long time, offering more tablet time as a reward works much less well.
- An effective painkiller reduces the value of “making the pain stop” — and pain-escape behaviors decrease.
- A child who has just received a lot of attention from the adult tends, for a while, to push less for attention.
A note on vocabulary: you will still find texts that call everything an “establishing operation.” The broader term motivating operation, with the EO/AO pair and the evocative and abative effects, was proposed by Michael and consolidated by Laraway, Snycerski, Michael, and Poling (2003), and is the standard adopted today in the field's textbooks.
Don't confuse it with the discriminative stimulusBoth are antecedents and both can evoke behavior — but for different reasons. The discriminative stimulus (SD) signals that reinforcement is available; the motivating operation changes how much that reinforcer is worth to the person at that moment. The coffee machine being switched on signals that you can get a coffee (SD); having stayed up all night is what makes the coffee worthwhile (MO). It was exactly this distinction that Jack Michael formalized, in 1982, when he separated the discriminative and motivational functions of stimuli.
Where that value comes from
Some motivating operations don't need to be learned: they are unconditioned (UMO), tied to biology — deprivation of food, water, sleep, oxygen, activity, sexual contact, getting too hot or too cold, and an increase in painful stimulation (which makes reinforcing anything that makes the pain stop). Others are conditioned (CMO): they acquire their effect through learning. Tap the cards:
Why this changes practice
Motivating operations are the part of the ABC that tends to go unnoticed — and that, once understood, makes it possible to prevent instead of merely reacting.
- Requests (mands). In Verbal Behavior (1957), Skinner defined the mand as the verbal operant that is under the control of a motivating operation: you ask for water when water is worth something. That is why teaching someone to request something only truly works when the item being taught matters at that moment — hence the importance of functional communication being trained in real situations of motivation.
- Assessment of challenging behaviors. In functional analysis, the test conditions manipulate exactly these MOs: attention deprivation, presentation of demands, removal of preferred items. That is what makes the function of the behavior show up clearly.
- Antecedent interventions. Offering attention frequently before it runs out, giving prior access to an item, adjusting the difficulty of a task, taking care of sleep, hunger, and the sensory environment: all of this operates as an abolishing operation, reducing the value of the reinforcer that maintained the difficult behavior — without depending on consequences.
- Choice of reinforcers. No reinforcer lasts forever. Varying items and avoiding satiation keeps teaching effective — the same sticker that was exciting on Monday may mean nothing by Friday.
A good question for everyday lifeBefore asking “how do I get them to stop?”, it's worth asking: what is making this worth so much right now? Hunger, poor sleep, noise, pain, boredom, too long without attention, a task that is too long. Many crises dissolve when the motivating operation is addressed — not when the consequence is made harsher.
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Further reading
- Cooper, J. O.; Heron, T. E.; Heward, W. L. Applied Behavior Analysis. 3rd ed. Pearson, 2020 (chapter on motivating operations).
- Michael, J. “Distinguishing between discriminative and motivational functions of stimuli”. Journal of the Experimental Analysis of Behavior, 1982.
- Laraway, S.; Snycerski, S.; Michael, J.; Poling, A. “Motivating operations and terms to describe them: some further refinements”. Journal of Applied Behavior Analysis, 2003.
- Skinner, B. F. Verbal Behavior. New York: Appleton-Century-Crofts, 1957.
- Moreira, M. B.; Medeiros, C. A. Princípios Básicos de Análise do Comportamento. 2nd ed. Porto Alegre: Artmed, 2019.
This entry is educational and does not replace assessment, diagnosis or treatment by a qualified health professional. Every person is unique — for a specific case, seek individual guidance.