2nd diagram on p. 43

The 2nd diagram on p. 43 bothers me because it comes too close to violating the Dead Man Test for my comfort when it says, in the Behavior box, Sue stops presenting the task. This seems more like a non-behavior than a behavior, & therefore something that a dead man could do. Instead of Sue's behavior being controlled by a reinforcement contingency, I think it's being controlled by a punishment contingency in which the Before condition is that she doesn't see Jimmy's discomfort, the Behavior is that she presents the task, & the After condition is that she sees Jimmy's discomfort.

Kinds of reinforcers, Part 3

Revised on 12/22/14

I suggest reading this post after you read the two posts called Kinds of reinforcers, Part 1 and Kinds of reinforcers, Part 2.

On p. 3 Malott tells us that a reinforcer is a stimulus that increases the frequency of a response it follows. Then on p. 4 he tells us that in order for a reinforcer to actually reinforce a particular response that it follows, the reinforcer must be delivered quickly. He says that one second or less is considered immediate reinforcement and up to 60 seconds is considered delayed reinforcement. So here are two more kinds of reinforcers – those that are delivered immediately following a behavior and those that are delayed.

So what about reinforcers that are neither immediate nor delayed? Can’t a reinforcer be delivered more than 60 seconds after a behavior occurs and still reinforce that behavior? Don’t we see this all the time? Suppose I say “Do me this favor and I’ll give you five bucks tomorrow.” Doesn’t the $5 reinforce the behavior of your doing the favor? No. Not according to what Malott says on p. 4.

Does that mean that the $5 is not a reinforcer? No, it doesn’t mean that. Go back to the definition of Reinforcer on p. 3. It’s a stimulus that increases the frequency of a response it follows. There’s nothing in that definition about following the response quickly. If the target behavior (that is, the behavior we’re focused on right now) is your doing me a favor, then if you do it and tomorrow I give you $5, AND (this is very important) you do favors for me more often in the future when I ask you to, then the $5 functions as a reinforcer.

Getting confused? Then read this very carefully or else you’ll get even more confused. A stimulus is a reinforcer if a behavior increases in frequency as a result of being followed by that stimulus, whether the stimulus followed the behavior quickly or not. But if the stimulus DOES follow the behavior quickly (preferably within 1 second, but at most within 60 seconds), then it DIRECTLY reinforces that particular behavior. If the stimulus follows the behavior by more than 60 seconds, and yet the frequency of the behavior still increases, then that stimulus is still a reinforcer, according to the definition. But it doesn’t DIRECTLY reinforce that particular behavior. Instead it INDIRECTLY reinforces the behavior. We’ll learn more about direct and indirect reinforcement in later chapters (like in Ch. 22).

This leads us to another very important principle, which is that behaviors increase in frequency ONLY when they’re quickly followed by delivery of a reinforcer. So if that’s true, you’re thinking, then how come a behavior that’s followed by a reinforcer more than 60 seconds later (maybe even as much as 15 minutes, a day, 2 months, ...) will still increase in frequency? It’s because in between that behavior and the delivery of that reinforcer, there must have been some other stimulus that quickly and directly reinforced the behavior. That’s the answer to the mystery. But it presents us with another mystery, which is “What is that other stimulus that quickly and directly reinforces the behavior?” Stay tuned.

Kinds of reinforcers, Part 1

On p. 3 Malott provides the definition of Reinforcer. Notice Positive Reinforcer in parentheses. This suggests that there are other kinds of reinforcers, which is correct. Later you’ll learn about negative reinforcers. What you need to know is that most of the time when reinforcer is used by itself, without positive or negative in front of it, that’s shorthand for positive reinforcer.

When the sight of the thing reinforces looking at it

Revised on 1/4/14

Malott's 2nd question on p. 6 (middle of 1st column) asks what reinforces the behavior of giving attention to Eric as he throws a tantrum. Watching something - Eric throwing a tantrum, a beautiful sunset, a good-looking person - is a behavior. And all behaviors require explanation.

Malott says that sometimes the sight of the thing we're looking at reinforces the behavior of looking at it. This is an example of a stimulus functioning as a reinforcer (remember the 4 kinds of reinforcers discussed on p. 3). The sight of something, the smell of something, the taste of something - these are all stimuli, & in the right circumstances, any of them might function as a reinforcer for a behavior that they immediately follow.

Anyway, Eric is throwing a tantrum & you watch him as he howls & flails about. Your watching is a behavior. Why do you do it? Because it's reinforced by the sight of the thing you're looking at.

Reinforcer is as reinforcer does

Revised on 1/4/14

Malott points out several places in Ch. 1 that whether or not something functions as a reinforcer in a particular instance depends on whether the frequency of the behavior it immediately follows increases when circumstances are similar in the future. That's kind of a tangled sentence, so you should re-read it as many times as you need to in order to understand what I just said.

One of the places he makes this point is on p. 8 (the "Reinforcer Assessment" section). We can't simply make the blanket statement that candy is a reinforcer, because for some people, if you give them candy immediately following a target behavior, the future frequency of that behavior doesn't increase. And even if candy often works as a reinforcer for someone, there may be times when it doesn't. So the only way to know for sure if something functions as a reinforcer for a given organism performing a given behavior in a given type of situation is to see if the frequency of that behavior increases when that organism is in a similar situation in the future.

Despite all this, it's certainly true that some things almost always function as reinforcers for most normal people in most normal situations. A good example is money. So as long as we realize the limitations of what we're saying, it's OK to refer to those things as reinforcers. Can you think of some examples?

What are the functions of the stimuli in a behavioral chain?

Revised on 3/29/14

The dual-functioning stimuli that link the responses in a behavioral chain function as reinforcers for the behaviors that precede them. The 1st stimulus or condition that starts the chain doesn't link two behaviors, so in analyzing a chain, we normally don't label that one as a reinforcer. The 2nd function of these stimuli may be S^D, EO, operandum, or opportunity to respond. This last option is not discussed in Ch. 20. It's briefly discussed in Ch. 22 (p. 354) but it's relevant here too. Without having it as an option for the 2nd function of these linking stimuli, we're handicapped in some cases. Anyway, figuring out which of these functions applies to a particular dual-functioning stimulus is one of the trickier things to do when analyzing a behavioral chain.

In this chapter, Malott's only discussion of a stimulus functioning as an EO is in the footnote at the bottom of p. 315, where he assigns that function to the stimulus that starts the behavioral chain he's describing. Can a dual-functioning stimulus in the middle of a chain also have the EO function? I think it can because the introduction of an EO increases the likelihood that the next behavior in the chain will occur, and that's the sort of thing these linking stimuli do to keep the behaviors happening one after the other. But that's not my main concern in this post.

My main concern is this opportunity to respond option. In Ch. 22 we're going to learn about analogs to discriminated avoidance. These are situations in which there's a deadline and the target behavior has to happen before the deadline or else you lose the chance to receive a reinforcer. We'll learn that in lots of these scenarios, the time before the deadline functions as an S^D, meaning that if the target behavior happens before the deadline, it's reinforced. And in those scenarios, the time after the deadline functions as an S^Δ, meaning that if the behavior happens after the deadline, it won't be reinforced. But, Malott explains to us, the time before a deadline doesn't always function as an S^D. It's not an S^D in cases where the target behavior, for various possible reasons, cannot be performed after the deadline has expired. If the target behavior can't be performed, this means the time after the deadline is not an S^Δ, which means that the time before the deadline is not an S^D. So if the time before the deadline is not an S^D, what is it? According to Malott, that stimulus condition is best labeled as an opportunity to respond (again, see p. 354).

Are you still with me? OK, then here we go, back to those dual-functioning stimuli in behavioral chains. When my students think up examples of behavioral chains, they sometimes have trouble figuring out the function of the stimulus/condition described in the 1st box as well as the other linking stimuli. I now realize that there are 4 possibilities: S^D, EO, operandum, or opportunity to respond. As an example of opportunity to respond, consider the example provided by one of my students. The 1st box says "Car is parked." The following behavior box says "Start car." The following dual-functioning stimulus box says "Car running." Is that first stimulus condition (Car is parked) an operandum? I don't think so. Is it an EO? I don't think so because if it was, that would mean that when the car is parked, the reinforcement value of "car is running" would be greater than if the car was not parked, that is, if the car was running or being driven. This doesn't make sense because in the latter condition (car is running or being driven), the behavior of starting the car can't be performed because the car is already started. Is it an S^D? I don't think so because the corresponding S^Δ would then be "car is running/being driven." And again, in that condition the behavior of starting the car couldn't be performed because the car is already running. So what's the function of the condition described in that first box, "car is parked?" I think it's an opportunity to respond.

So some quick guidelines for figuring out the functions of the initial stimulus/condition and the linking stimuli:

Is it an S^D? Figure out what its corresponding S^Δ would be. Then ask yourself two questions: (1) In the S^Δ condition, could the following behavior be performed? If not, then this condition is not an S^Δ, which means that the stimulus/condition in question is not an S^D. (2) In the S^Δ condition, if the following behavior could be performed, would it be followed by the reinforcer that's described in the next stimulus box? If so, then then this condition is not an S^Δ, which means that the stimulus/condition in question is not an S^D.

Is it an EO? Look at the reinforcing stimulus that results from the behavior. Is it a more powerful reinforcer for the behavior because of the presence of the stimulus/condition in question? If so, then it's an EO.

Is it an operandum? Does the stimulus/condition constitute making available some "thing" that you must have in order to perform the following behavior? An example is "fork in hand" when the following behavior (such as "put fork in potato") can't be performed without that "thing." If so, then it's an operandum.

Is it an opportunity to respond? Similar to operandum in that without either - operandum or opportunity to respond - the following behavior can't be performed. Here, tho, the inability to perform the behavior is not because some implement or object is not available, but for some other reason it's not possible to perform the behavior, like in the "car is parked" example above.

Have fun figuring out the dual functions of these linking stimuli in behavioral chains!

Choosing target behaviors for contingency analyses

Revised on 1/4/14

Take a look at an earlier post with the "Principles of Behavior: Ch. 02" label for tips about preparing the reinforcement CA. This post will elaborate on some of what was written there.

One of the most common errors that students make with CAs is in identifying the target behavior. Because the courses that use Malott's book focus on the basic behavioral contingencies, the examples of contingencies that you use in your CAs should use simple, discrete behaviors. "Discrete" means not consisting of multiple parts. So you should not use behaviors that are actually behavioral chains consisting of a sequence of connected behaviors. An example of a behavioral chain is baking a cake, which is not a discrete, unitary act, but several acts or behaviors performed one after the other until you're finished. You should not use any other "collection" of behaviors either. Doing your homework or cleaning up your room, for instance, are collections of separate behaviors, consisting of any number of individual behaviors. Often these collections of behaviors have other, unrelated, behaviors interspersed. So you might work for a while on your homework, or pick up a few things in your room, then take a break, get a bite to eat or go to the bathroom, then resume working on your homework or cleaning your room. Collections of behaviors like this don't work for the kinds of CAs we're doing. One of the reasons is that in this kind of situation, it's not possible to specify what is meant by "immediately following the target behavior."

The target behaviors you choose should have a clear starting point, a clear ending point, and between the starting and ending points there should be no interruption and no interspersed behaviors.

The one possible exception is the reinforceable response unit (RRU), which you can read about on p. 374. An RRU meets the criteria I just spelled out in the preceding paragraph, so it's acceptable. But if you specify an RRU as the target behavior in one of your CAs, be careful, because they're rare in real life, and your CAs need to be faithful to real life.

Comparing graphs

We often need to analyze and compare cumulative graphs. Malott discusses the cumulative graph in Ch. 17 and Cooper, Heron, and Heward discuss it in Ch. 6. Three basic ways in which you can compare graphs are in terms of their level, trend, and variability.

The level of behavior depicted on a graph refers to the average frequency of the behavior across time. Calculate it by dividing the number of responses by the amount of time in which those responses were made. For example, if a rat pressed a lever 120 times in an hour, then one way to express the level of behavior would be 2 responses per minute (120 lever presses divided by 60 minutes). When visually analyzing a graph, imagine a straight horizontal line running across the graph at the level on the vertical axis that represents the average frequency based on all the data points. Sometimes a graph actually shows this "mean level line" (sometimes it's a "median level line"). The higher the mean level line is from the baseline, the greater the average frequency of the behavior across the period of time represented by the graph.

Trend refers to the overall tendency across time for the behavior to increase in frequency, decrease in frequency, or remain stable. Again, imagine a straight line, this time running through the data points in such a way that approximately half of them are above the line and half of them are below the line. If this trend line is horizontal, it tells you that, overall, the behavior did not change in frequency over the time period represented by the graph. If the line slopes upward from left to right, the frequency increased across time, and if it slopes downward, the frequency decreased. Another word for trend that you'll often see is slope.

Variability refers to the average change in frequency from one data point to the next. Imagine the trend line again. If the actual data points tend to be far from the line, then variability is high. This would indicate that the frequency of the behavior tended to change a lot from moment to moment during the session. There were periods of fast responding mixed in with periods of slow responding. We'd probably describe a line like this as very "jagged." When variability is low, the line is less jagged, more smooth.

The following graph shows a low level of behavior, a near-zero trend, and low or fairly stable variability.


The following graph shows a moderate level of behavior, an increasing trend, and high variability. Notice that a trend line has been added.


The following graph shows a low level of behavior, a slightly increasing trend, and moderate variability:

What gets paired in a verbal pairing procedure?

Several times in the chapters on rule-governed behavior (23, 24, 25, maybe elsewhere too), Malott discusses the verbal analog to the pairing procedure (“verbal pairing procedure” for short). Remember that a neutral stimulus becomes a learned reinforcer or a learned aversive stimulus (punisher) by being paired with a stimulus that’s already a reinforcer or aversive stimulus (Ch. 11). Like this...


According to Malott’s theory of how rule-governed behavior works, in order for a rule to control behavior, there has to be an aversive stimulus/condition that’s escaped by performing the target behavior that the rule specifies. This direct acting escape contingency is the engine at the heart of rule control. If behavior is controlled by its immediate consequences, as Malott posits, then in order to understand any behavior, including complex rule-governed behavior, we have to dig deep until we uncover whatever direct acting contingency is actually doing the work of controlling the behavior.

So in rule-governed behavior, where does the necessary aversive stimulus/condition come from? Malott makes it clear that when a rule is stated (by someone else or by oneself), and if there’s a deadline, then the combination of noncompliance with the rule (not performing the target behavior) and the approaching deadline constitutes an aversive stimulus/condition. It’s a conditional aversive stimulus because each of the two components (noncompliance and approaching deadline) by itself would not be aversive. The aversiveness of one of the components is conditional upon its being combined with the other.

But what still requires a little further clarification, I think, is why that conditional stimulus is aversive. The mere combining of noncompliance and an approaching deadline isn’t necessarily aversive. For instance, consider this rule: Take your kid to the dentist before the end of the week and you’ll receive 5 cents. Most of us would not worry about losing the opportunity for that 5 cents. So noncompliance (I haven’t taken the kid to the dentist yet) plus the approaching deadline (It’s already Friday afternoon) would not constitute an aversive stimulus/condition. But if the amount were $100 instead of 5 cents, we’d probably worry and noncompliance plus approaching deadline would be aversive. So whether or not this kind of conditional stimulus is aversive depends on the consequence specified in the contingency that the rule describes. If the consequence is sizable enough and/or probable enough, then the conditional stimulus (noncompliance + approaching deadline) will be aversive.

So back to the original question about the verbal pairing procedure. Remember that in order to turn a neutral stimulus into an aversive stimulus, it has to be paired with an already-aversive stimulus. As explained above, noncompliance with a rule plus an approaching deadline constitutes a conditional stimulus which, by itself, is neutral, that is, it’s not aversive. It only becomes aversive when it’s paired with an already-aversive stimulus, such as loss of the opportunity to receive a sizable and/or probable reinforcer. Like this…


Pardon me for getting mentalistic for just a moment, but this “pairing” doesn’t take place in the outside, observable world, but “in your head.” The proper way to say that is that the neutral conditional stimulus and the already-aversive stimulus are “verbally paired.” Or to say it another way, because we’re not talking about actually physically pairing two stimuli, this is a verbal analog of the pairing procedure.

Anyway, this verbal pairing procedure makes “it's Friday afternoon and kid hasn't been taken to dentist” an aversive condition. So now it can function as the before condition in the direct acting escape contingency that ultimately controls the target behavior, as in the diagram in the 2nd column on p. 405. This contingency and the 3rd contingency in the 1st column on that page are essentially the same, or at least we’ll treat them the same for now. I believe the before conditions described in these two contingencies are different from each other. But for present purposes they can be treated as interchangeable because under normal circumstances they would always occur together.

Tinkering with some contingencies in Ch. 26B

(1) In Ch. 26B on the web, Malott calls the contingency at the top of p. 7 an analog to penalty. But I think it's an analog to punishment by prevention of a reinforcer. What do you think?

Before: You will enter Heaven when you die.
Behavior: You dump a barrel of toxic waste.
After: You will not enter Heaven when you die.

(2) At the bottom of p. 12 there's a description of a rule-governed analog to punishment, and on the top of the next page it's diagrammed, but incorrectly, I think. It seems to me that the diagram should say:

Before: You won't enter Hell when you die.
Behavior: You commit one mortal sin.
After: You will enter Hell when you die.

(3) On pgs. 13-14 Malott offers the example of an analog to avoidance of the loss of the opportunity for a reinforcer (AALOR). As we've learned, if a contingency looks like an analog to reinforcement, but it includes a deadline, then it's really an AALOR. In this example, the rule is to do a good deed before the end of the day so you'll go to Heaven if you die before you wake. Malott says the deadline is the end of the day and that it functions as an S^D. But I don't think so. I think the deadline is something like "before you fall asleep and never wake up." If this rule is effective in controlling someone's good deed behavior, it's because noncompliance as sleepy time approaches is highly aversive since you won't get another chance to earn entry into Heaven if you die before you wake. This deadline is not an S^D because the corresponding S^Δ would be something like "after you wake up, still alive." In that circumstance, the target behavior of doing a good deed would still earn the reinforcer of getting to Heaven, or at least getting closer. So I think this is another example of a deadline that functions as an opportunity to respond. So I'd change the diagram at the top of p. 14 to:

Before: You won't go to Heaven.
Opportunity to Respond/Deadline: Before you fall asleep and never wake up.
Behavior: You perform a good deed.
After: You will go to Heaven.

(4) The stranded motorist scenario is another example in which the deadline functions as an opportunity to respond rather than as an S^D.

Another "opportunity to respond" vs. SD

On p. 366 Malott explained how some stimulus situations that were formerly thought to function as S^Ds don't really fit that definition. The example was Mary having to eat her meal before the deadline (mealtime's end) in order to avoid losing the reinforcer that would be delivered the next day. If that deadline functions as an S^D, then the corresponding S^Δ would be after mealtime ends. The problem with that is that after mealtime ends, it's no longer possible to carry out the target behavior of eating her meal. So instead of the deadline functioning as an S^D, Malott tells us it functions as an "opportunity to respond." This is like situations in which an operandum (e.g., the lever in a Skinner box) might seem to function as an S^D but, in fact, since the target behavior cannot even occur in its absence, the presence of the operandum really functions as the opportunity to respond.

OK, on to p. 380. Carefully think about the examples diagrammed there. It seems to me that after the play ends (labeled as the S^Δ), the target behavior of making a good play cannot be performed. If I'm right about this, then in those two diagrams, there should be no S^Δ box nor its corresponding "after" box, and the box describing the deadline should be labeled "Opportunity to respond" instead of S^D.

What do you think?

Does feedback really function as an SD?

I don’t think so, and I think Dr. Malott might agree. It’s obvious from reading his book that he and his team are always thinking more and more deeply about various issues. And my guess is that deeper thought about this issue will result in the view that rather than feedback functioning as an S^D, it functions more like a prompt.

Here’s why. In order for there to be an S^D, there also has to be an S^Δ, which is a stimulus in the presence of which the target behavior is not reinforced/punished. So think about the football scenario in Ch. 23. If feedback delivered before a play functions as an S^D, in the presence of which the target behavior will be reinforced, then the corresponding S^Δ would be no feedback delivered before the play. But if no feedback were delivered before the play, yet the target behavior occurred anyway (that is, the play was executed correctly), it would still be reinforced. This means that the “no feedback” condition is not an S^Δ. And this further means that feedback is not an S^D.

Now remember the definition of prompt - a supplemental stimulus that raises the probability of a correct response. Seems to fit, right?

Motivating operations

The concept of motivating operation (MO) is defined and discussed quite differently in Ch. 16 of Applied Behavior Analysis and in Ch. 9 of Principles of Behavior. In the former, Michael defines and describes MOs as having two kinds of effects – behavior-altering (BA) effects and value-altering (VA) effects. BA effects are the temporary effects of the MO on the frequency of current behavior. For example, the MO of food deprivation temporarily increases the frequency of behaviors that have been reinforced by food in the past. VA effects are the temporary effects of the MO on the reinforcing or punishing effectiveness of a stimulus, event, object, or condition. For example, the MO of food deprivation temporarily increases the reinforcing effectiveness of food.

These two effects of an MO are usually presented as if they were two different and independent types of effects that are brought about by an MO. But in my opinion this is an incorrect understanding. An alternative description of an MO's effect, which I prefer, is that MOs have only one kind of effect – a behavior-altering effect. An MO causes a change in the frequency of behaviors that have been reinforced or punished by a stimulus, event, object, or condition in the past. The so-called value-altering effect is not a second, different effect that's independent of the BA effect. We see that when we realize that the value or effectiveness of a reinforcer or punisher can only be understood in terms of whatever changes in behavioral frequency are observed. In other words, when we talk about an MO's value-altering effect, it's really just another way of talking about its behavior-altering effect.

Malott seems to be on the same track, although he doesn't say so explicitly. But he defines MO as "a procedure or condition that affects learning and performance with respect to a particular reinforcer or aversive stimulus." By "affects learning and performance" he can only mean "changes the frequency of the target behavior." So this definition focuses on the MO's BA effects and says nothing about the value or effectiveness of the relevant reinforcer or punisher (which he calls "aversive stimulus"), that is, it says nothing about the MO's VA effect.

As Michael points out in Ch. 16 of ABA, there's still a lot of work to be done before we'll fully understand MOs, especially MO's for punishment. In the meantime, I think Malott's definition is not only simpler to understand, but I also think it's more conceptually accurate because of its focus on the MO's BA effect without claiming that MOs also have a VA effect.

Kinds of reinforcers, Part 2

Revised on 12/22/14

I suggest reading this post after you read the post called Kinds of reinforcers, Part 1.

See the definition of Reinforcer (Positive Reinforcer) on p. 3. Be sure you understand that stimulus is not a synonym of reinforcer and reinforcer is not a synonym of stimulus. These two words DO NOT mean the same thing. Stimulus is the larger category and reinforcer is a subcategory of that larger category. So every reinforcer is a stimulus, but not every stimulus is a reinforcer. Sometimes a particular stimulus functions as a reinforcer, but sometimes it has a different function.

Stimulus, like many other words, has multiple meanings. In the second column on p. 3 Malott says that a stimulus is any physical change, such as a change in sound, light, pressure, or temperature. This is a “default” definition of stimulus as the word is commonly used in everyday language. In his list of four types of stimuli, Malott refers to this as the “restricted sense” of the word. But he also says that throughout Principles of Behavior, when the word is used, it might refer to this kind of physical change, but it also might refer to an event, activity, or condition. So looking again at the definition of Reinforcer (Positive Reinforcer), we should understand that a stimulus that functions as a reinforcer might be a physical change, event, activity, or condition. Any of these kinds of stimuli might function as a reinforcer in a particular situation.

Another way to think about Malott’s list is that there are four basic kinds of reinforcers. A stimulus (in the restricted sense of the word), such as a pleasant taste or aroma, can function as a reinforcer. So can an event, like a football game or a concert. So can a condition or, more specifically, a change in condition. For instance, if it's dark and you can't see, then the behavior of flipping a light switch may change the visibility condition, and that change in condition is a reinforcer. As for activities as reinforcers, I'll expand a little on what Malott says. Rather than an activity functioning as a reinforcer, it's more often the opportunity to engage in a particular activity that functions as a reinforcer. For example, if you wash the dishes (target behavior), you'll have the opportunity to engage in the activity of playing video games for a while. That opportunity, then, functions as a reinforcer.

More on SDs & SΔs

According to Malott, and just about everyone else as far as I can tell, the term, discriminative stimulus, is the "proper" name for the antecedent variable whose abbreviation is S^D. Its opposite, whose abbreviation is S^Δ, doesn't seem to have a proper name. Instead, we're usually told that the abbreviation stands for S-delta, which is really just a way of spelling out S^Δ that makes it clear how it should be pronounced and accommodates keyboards that don't know Greek.

In my opinion, discriminative stimulus should be the label for the category of antecedent variables that includes both S^D and S^Δ. In other words, there are two kinds of discriminative stimuli – S^Ds and S^Δs. An S^D is a stimulus in the presence of which a particular response will be reinforced or punished (depending on whether we're dealing with a reinforcement or punishment contingency), and an S^Δ is a stimulus in the presence of which a particular response will not be reinforced or punished.

SD & SΔ: Two sides of the coin

Revised on 3/29/14

Malott’s definitions of S^D and S^Δ are procedural (see footnote on p. 199). They’re stimuli in the presence of which a reinforcement or punishment contingency is present or absent. This is different from the way some others define these terms. As Malott points out, some other definitions put the emphasis on either (1) the likelihood of the response happening in the presence of the stimulus, or (2) the likelihood that, if the response happens in the presence of the stimulus, it will be reinforced/punished. These two events – response happening and response being reinforced/punished – both depend on whether the reinforcement/punishment contingency is present or absent. This seems to make the presence or absence of the contingency primary and those two events are secondary.

An S^Δ is a stimulus in the presence of which the target response will not be reinforced/punished because the relevant contingency is absent. If there are no stimuli (circumstances, settings, occasions) in the presence of which the target response would not be reinforced/punished, then by definition there’s no S^Δ. This also means that the contingency is present all the time, so that there’s no particular stimulus “signaling” that the contingency is present. All of this is why Malott says that if there’s no S^Δ, then there’s no S^D.

The thing about coins is that they have two sides. There’s no such thing as a one-sided coin; you can’t have one without the other. And if you DON’T have one of them, then you don’t have the other either. That’s the way it is with S^Ds and S^Δs. If you don’t have an S^Δ, then you don’t have an S^D either (and vice versa, of course).

How do analogs to punishment work?

In Ch. 24 Malott explained in great detail how rule-governed analogs to avoidance of the loss of a reinforcer work. Now maybe I just missed it (always possible), but I don't think he's explained how rule-governed analogs to punishment work. In the PDF version of Ch. 26 he writes “Commit a single mortal sin and you will definitely spend eternity in hell. The statement of that rule does make noncompliance a most aversive condition (for believers). This is an effective rule-governed analog to punishment.” So what is the mechanism by which a rule like this works?

For rule-governed analogs to avoidance of the loss of a reinforcer, stating the rule establishes noncompliance (not performing the target behavior) as an aversive before condition which can be escaped or decreased by performing the target behavior. This outcome follows the target behavior immediately and the result is an increased frequency of the target behavior in similar situations.

But in a rule-governed analog to punishment, noncompliance with the rule means PERFORMING the target behavior, and noncompliance (having performed the target behavior) is an aversive AFTER condition. Depending on the particular circumstances, that aversive condition might be what we'd call guilt or, perhaps, fear of punishment. This aversive after condition follows the target behavior immediately as part of a direct-acting punishment contingency. When a rule is stated prohibiting a behavior, that behavior becomes a member of the response class of prohibited behaviors. Even if the particular target behavior has never been performed before, other prohibited behaviors have been performed in the past and have been punished. So because members of this response class have been punished in the past, resulting in a decreased frequency of performing such behaviors, the frequency of newly prohibited behaviors should also be reduced.

I think that's how rule-governed analogs to punishment work.

Direct-acting, indirect-acting, and ineffective

All behavioral contingencies consist of three elements: the occasion for a behavior/response, the actual behavior/response, and the outcome of the behavior/response (p. 16). The contingencies we learned about first are the direct-acting contingencies, which Malott defines on p. 366 as those for which "the outcome of the response reinforces or punishes that response." The outcome (such as presentation of a reinforcer or an aversive stimulus) reinforces or punishes the target behavior because it immediately follows that behavior. In other words, the outcome directly affects the future frequency of the target behavior.

Indirect-acting contingencies consist of the same three elements, but we call them indirect-acting because the outcome (such as presentation of a reinforcer or an aversive stimulus) does NOT reinforce or punish the target behavior because it does not immediately follow that behavior but, instead, comes after some delay. This delayed outcome still affects the future frequency of the target behavior, but it affects it indirectly instead of directly. These indirect effects on the behavior's frequency are not called "reinforcement" or "punishment" because, by definition, reinforcement and punishment involve outcomes that follow the target behavior immediately.

These indirect-acting contingencies are one type of analog contingency (or what Malott calls "analogs to behavioral contingencies"). They're analogs because they resemble the direct-acting contingencies, but they're different because of their delayed outcomes. For our present purposes, indirect-acting contingencies and analog contingencies are the same thing.

In order for an indirect-acting contingency to be effective (affect the future frequency of the behavior), the contingency must be described to the behaver. A statement that describes a contingency (direct-acting or indirect-acting) is a rule. If the statement of a rule describing an indirect-acting contingency affects the frequency of the target behavior, then we can say that the behavior is "rule-governed."

When we talk about analog/indirect-acting contingencies, we need to say more. We need to say what kind of analog/indirect-acting contingency we're talking about. For instance, in Ch. 22 Malott talks about analog reinforcement contingencies and analog discriminated avoidance contingencies.

To our visitors...

It could be that some folks who are not fellow students in your class may be visiting the ole DMT site from time to time. If so, this post is intended mainly for them.

I hope our guests will feel free to explore and to add their comments to any of the posts here. For now, at least, things are set up so that anyone can add comments without restraint. I trust that all comments, whether from students or guests, will be offered in the same spirit that motivated creating DMT in the first place. That spirit is best-expressed in the words of Rudolph the Rat, who appears in the upper-left of our front page. Getting a little more specific, our goal at DMT is for more and more people to learn the principles of behavior analysis and how to use them to improve our lives. And we're always open to suggestions about how we can do that better. If you'd like to communicate directly with me (PW), you can send an email to williamspsATgmail.com (replace AT with @).

How do you avoid something immediately?

Most of the behavioral contingencies that we deal with in Principles of Behavior have immediate consequences, that is, reinforcing or aversive consequences that follow the target behavior immediately. Starting with Ch. 22 we get deeper into analog contingencies, which often means that the consequences don't follow the target behavior immediately, or so it seems. Actually, we'll learn that even with these analogs, the consequences that directly affect the future frequency of the target behavior do, indeed, follow the target behavior immediately.

But I digress .... In the case of some avoidance contingencies, it's hard to see how this immediacy criterion applies. In other cases it's obvious. If you're a race car driver whizzing around a track surrounded by lots of other drivers in close quarters, you're going to experience something pretty aversive any second unless you're continuously performing several different behaviors. Because all kinds of nasty stuff threatens to happen to you immediately, within seconds if not less, then whatever behaviors you perform to prevent those things from happening have the immediate consequence of avoiding/preventing aversive consequences. This is the sense in which the consequences of avoidance follow the target behavior immediately.

What that means when you're inventing avoidance CAs is that the aversive stimulus described in your before box must be something that's going to be experienced within seconds UNLESS the target behavior happens. Another way to say this is that the aversive stimulus is going to experienced within seconds unless the next thing you do is the target behavior.

What that also means is that behaviors like taking an alternate route so you won't have to put up with the heavy traffic on your regular route, or telling them to "hold the onions" when you order bean burritos from Taco Bell so you won't gross out everyone you talk to, are not examples of avoidance. In this latter case, when you tell them to hold the onions, you haven't yet eaten them, right? So at the time you tell them to hold the onions, the aversive condition of onion breath is not going to happen within seconds. That aversive condition won't happen unless you do something else first, namely actually eating a burrito with onions on it. So telling them to hold the onions is not an avoidance behavior. In an avoidance situation, the aversive stimulus or condition is going to happen within seconds unless the next thing you do is the target behavior.

But even though it's not avoidance, you should still tell them to hold the onions.