Unit 2: Behaviorism
Readings
Instructor notes
Web resources
Readings
Driscoll, Chapter 2Optional: Gredler, Chapter 5
Additional reading: Munson & Crosbie, 1998. Effects of response cost on computerized program instruction. Psychological Record, Spring 98, Vol. 48, Issue 2.
This article is to be skimmed, not read for detail. (See the last paragraph of the Instructor Notes section for an explanation.) To access this article online, go to the IUB Libraries Web site and connect to the Academic Search FULLTEXT Elite database. (There is also a link to the Libraries site from the P540 Web Resources page.)
Instructor notes
Important ideas leading up to Skinner
Skinnerian behaviorism had important antecedents, including:
- Associationism, and Ebbinghaus's experiments with memorizing lists of nonsense syllables. Why did Ebbinghaus conduct his learning experiments with nonsense syllables? And, in retrospect, why was that perhaps not such a great idea?
- Thorndike's interest in the association between the environment and action (or behavior), rather than just the association between ideas.
- Pavlov's "discovery" of classical conditioning, where a previously "neutral" event (e.g., ringing a bell), when paired with a biological stimulus (e.g., food) can come to elicit the same physiological response (e.g., salivation).
Some concepts associated with the classical conditioning paradigm:
- Higher-order conditioning: when a conditioned stimulus is paired with another previously neutral stimulus, it too can acquire the ability to elicit a response. So, if Pavlov's dogs were conditioned to salivate when he rang a bell, then he began flashing a bright light at the same time, eventually the light alone might come to elicit the same response.
- Extinction: when the conditioned stimulus is presented over a sufficient period of time without the unconditioned stimulus, the conditioned stimulus eventually loses its ability to elicit the response. (i.e., ring that bell enough times without presenting food, and the dog will stop salivating.)
- Counter-conditioning: Changing the response to a conditioned stimulus by pairing it with a different stimulus. In the case of Baby Albert, you might pair a pleasant stimulus with the white rat, just in case extinction alone doesn't work. Or, in the case of Pavlov's dogs, you might pair an appetite-suppressing stimulus with the conditioned stimulus.
Skinner's operant conditioning
Watson (1913) introduced the notion of behaviorism: that psychology should be concerned only with the objective data of behavior, since we can't really know what's going on in the mind. B. F. Skinner followed Watson's lead in emphasizing behavior, rather than thoughts, feelings, attitudes, etc., as the "proper" subject matter of psychology. The interesting difference in Skinner's view is that he was less concerned about the relationship between environmental stimuli and responses; rather, he was mainly interested in behavior (or a response) and its consequences. Attempts by psychologists to link all behaviors to stimuli from the environment had become very cumbersome, and required postulating a lot of intervening mental processes. Just imagine starting only with stimuli that elicit physiological responses (heat, loud noises, hunger, etc.), and trying to account for complex human behavior like building a cathedral or writing a poem!
Skinner said that the environment provides us with "cues" that serve as antecedents for behavior; i.e., they set the conditions for it to occur. But it's the results or consequences of our behavior which make that behavior more or less likely to occur in the future, and so it was these results that were more interesting to him.
Thus, Skinner distinguished two classes of behavior: respondent and operant. Respondent behavior is the kind we perform automatically in the presence of some stimulus from the environment. Operant behavior is "emitted" without necessarily following any particular stimulus. For example, babies grasp at things and babble, just because that's what babies do. To Skinner, it would be the consequences of their grasping or babbling behavior that are important.
According to Skinner, the basic "unit" of behavior analysis is a discriminative stimulus, followed by an operant response, followed by a contingent stimulus. This is commonly diagrammed something like this:
S (discrim) --> R --> S (conting)
Remember that the discriminative stimulus sets the stage for the response, but does not automatically elicit it in the way that an object moving toward your eye can elicit a blink. For example, robins peck for worms when they're on the ground, but not when they're flying. So, the ground is a discriminative stimulus for pecking behavior. The pecking behavior (the R in our diagram) may be followed by getting a worm. If so, the worm is a new stimulus, which is contingent on the pecking behavior, and which may serve to reinforce that behavior.
Humans, too, are very sensitive to discriminative stimuli. We know that very different sets of behaviors are appropriate for different settings. For example, the behaviors that are appropriate at a football game are quite different from those that would be appropriate at an opera. While Skinner had some interest in the role of discriminative stimuli in setting the stage for behavior, he was more interested in the consequences of behavior; that is, in the response-contingent stimulus that follows a response.
Consequences of a response
Skinner noted that the consequences of a response (the contingent stimulus) can be either satisfying or unsatisfying to the person or organism making the response. When the consequence is satisfying, it is said to reinforce the behavior; that is, to make it more likely to occur in the future. When the response is not satisfying, or aversive, it is said to punish the behavior; that is, to make it less likely to occur in the future. It's important to remember that we can't always guess what consequence will be satisfying to someone. The final test of whether a consequence is reinforcing to someone is whether or not it increases the behavior of interest. Suppose, for example, that we try to get a child to go to bed on time by reading to her for half an hour each night. No matter how much we believe that the child enjoys being read to, if this does not increase her going-to-bed-on-time behavior, then, in Skinnerian terms, we must conclude that this was not a sufficient reinforcer for her. Or (and this may be the case), that our reading reinforces several delay tactics and makes them more likely to occur again.
Operant conditioning would be a fairly simple concept if it were concerned only with positive and negative consequences of a behavior or response. But it's a little more complicated than that. Skinner reasoned that we could think not only about situations in which a satisfying or aversive outcome was presented following a response, but also about situations in which it was removed following the response.
Suppose, for example, that every time your dog sniffs around on top of the kitchen stove, he finds a chicken leg or something equally tasty to eat. It is likely that his stove-sniffing behavior would increase, because it has been reinforced by finding food there. Now suppose that you get tired of this and you stop leaving food on top of the stove where the dog can reach it. This is a situation where a satisfying outcome is removed, rather than presented, following the response. And the likely consequence (you hope) is that the stove-sniffing behavior would decrease, through the process of extinction.
Here's another example. Suppose every time a student asks a question in class, the teacher responds in a curt or abrupt way. This may function as a punishing consequence which decreases the question-asking behavior. Then, a new teacher who is more open to questions takes over the class. The punishing or aversive consequence has been removed, so the student may increase the question-asking behavior.
If we "cross" the two possible functions of a contingent stimulus (satisfying or aversive) with the two possible conditions of presenting or removing the stimulus after the response, then we get the table with four cells that you see on page 39 of the text.
To analyze behavior a la Skinner, it is important to understand these four possible situations. In particular, note that both positive reinforcement and negative reinforcement (the upper left and lower right cells in Driscoll's table) serve to increase or strengthen behavior. Positive reinforcement does so by presenting a satisfying outcome after the response; negative reinforcement does so by removing an aversive outcome after the response. Also, both punishment, and response cost, timeout, and extinction (the upper right and lower left cells) serve to decrease or weaken behavior. Punishment does so by presenting an aversive consequence following the behavior. The others do so by removing a satisfying consequence following the behavior. Note: presenting an aversive outcome is sometimes referred to as presentation punishment, while removing a satisfying outcome is referred to as removal punishment.
Let's see how well you understand the four different consequences which can be applied after a behavior. Test yourself below by trying to decide which example is presentation punishment, removal punishment, positive reinforcement, and negative reinforcement.
Your dog, upon hearing classical music, begins howling and your quiet moment is broken. Now, you no longer listen to classical music. [click for answer] You are at work and point out to your boss an egregious spelling error in a memo he/she writes. Your performance review later that day is particularly harsh. You no longer point out your boss' spelling errors. [click for answer] You wake up every morning and place your feet on the cold tile floor. As you find this unpleasant, one morning you put on your slippers and your feet are not cold. Your behavior of putting on slippers increases. [click for answer] You decide you would like some quiet time before going to bed each night. You turn on a classical CD and dim the lights. You wake up the next morning feeling refreshed so you do it again the next night. [click for answer]
Learning new behaviors and maintaining established ones
So far, we've considered only behaviors that the person (or animal or organism) already knew how to perform. The only issue was whether the frequency of the behavior would be increased or decreased. But how does behaviorism account for learning to perform new behaviors? In your text, four processes are suggested:
- Shaping involves the reinforcement of successively closer approximations of some target behavior. For example, if you want to teach your dog to fetch the newspaper, you might begin by rewarding him when he approaches the door, then only when he goes out onto the sidewalk, then only when he approaches the newspaper, then only when he picks it up, then, finally, only when he performs the target behavior of bringing the paper to you.
- Chaining teaches complex behavior by reinforcing the performance of simpler behaviors which are then strung together in the proper sequence to make up the more complex behavior. For example, if I want to teach someone to assemble an electronic component from a kit, I might first teach the individual steps of assembly (with appropriate reinforcement after the completion of each task), then reinforce the learner only when she can assemble a particular module, then finally only when she can assemble the entire component.
- Discrimination learning is the process of learning to discriminate between settings in which a particular behavior will or will not be reinforced. For example, if I'm learning to work simple arithmetic problems, I must know to add in the presence of a plus sign (a discriminative stimulus), but not to add in the presence of a minus sign.
- Fading is the gradual withdrawal of prompts or cues (discriminative stimuli) that guide the performance of a complex behavior. For example, when my friend was first learning to play chords on a guitar, he needed lots of prompts, such as diagrams of the chord, a picture of someone with their fingers in the proper position, and a teacher who actually placed his fingers in the proper position. Later, he needed fewer and fewer prompts to be able to form the chord correctly.
To this point, we have assumed that a behavior is reinforced every time it is performed. However, behaviorists found that this need not be the case. Once a behavior has been established, reinforcement "schedules" other than one reinforcement for every performance turn out to be more effective at maintaining high response rates. Be sure you are familiar with fixed/variable ratio and interval schedules. Check your understanding below:
Suppose a teacher takes her class to the library to work on an assignment. She gets called away to monitor another teacher's class. As she leaves she tells the students:
I'll be back every 5 minutes to check on you. You'd better be good. [click for answer] You never know when I'll be back to check on you; it could be 5 minutes, it would be 10 minutes. You'd better be good. [click for answer] When you have completed the first 5 questions, send someone to get me and I'll let you know what to do next. You'd better be good. [click for answer] When I come back I'm going to check to see how many questions you've completed. I expect you to get as many done as you can. You'd better be good. [click for answer] Which schedule would lead to the fastest learning? Which would be most resistant to extinction? Overall, which would you recommend to this teacher?
Behaviorism and education
One of the most lasting influences of behaviorism in education is in the use of principles of behavior management. Many teachers have used ideas such as "time out" and token economies to reward on-task classroom behavior and discourage disruptive behaviors.
Behaviorism also had a pervasive influence on instruction and instructional design, although that influence has faded considerably over the past two decades. Contemporary computer-assisted instruction is a direct descendant of teaching machines and programmed instruction, both of which were attempts to create a technology of teaching in accordance with behaviorist learning principles. Instruction created according to behaviorist principles (especially programmed instruction, early computer-based instruction, and some contemporary computer-based tutorials and drill-and-practice) typically emphasized these characteristics:
- Emphasis on specific, observable learning outcomes. The target behaviors needed to be specified so that the instructor or designer could provide appropriate reinforcement when they were achieved.
- Individualized learning. Each learner worked independently, at his/her own pace. This permitted "reinforcement" to occur at the moment the learner completed a particular objective.
- Frequent reinforcement. The material to be learned was broken into very small "chunks", usually somewhere between a paragraph and a page of text. This was so that the learner could be reinforced frequently while working through the material.
- "Knowledge of correct results" as a reinforcer. The usual pattern of this kind of instruction was to present a small amount of reading or a problem, then to pose a question. In behaviorist terms, the reading or problem was a discriminative stimulus; when the student answered the question, they were emitting a response; and reinforcement that followed the response was finding out whether they had answered the question properly. Typically, these should be administered frequently and should cover little new content so that the odds of producing an incorrect answer to the discriminative stimulus (the Q) would be decreased (that would reinforce the wrong answer).
- Fading of prompts. In more sophisticated behaviorist instruction, the learner would be provided with less and less guidance or prompting as he/she proceeded through the material.
One of the reasons that this kind of instruction has largely disappeared is that it emphasized lower-order skills such as memorization. It is very difficult to teach higher thinking skills such as synthesis and evaluation in this instructional format.
However, to paraphrase Mark Twain, reports of the demise of behaviorism as the basis for instructional design are greatly exaggerated. The additional reading listed for this unit is an example of a very contemporary research study that is squarely in the behaviorist tradition.
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Web resources
The Web Resources page has links to several sites about behaviorism, including information about John Watson and B.F. Skinner, the fathers of behaviorism.
Comments: joalexan@indiana.edu
