Invitation to Psychology - Chapter 9 - Learning and Conditioning PDF

Psychology in the News First Grader Suspended Over Camping Utensil NEWARK, DE, October 12, 2009. Zachary Christie him because the district bans knives regardless of the was so excited about joining the Cub Scouts and going possessor’s intent, age, or character...

Psychology in the News First Grader Suspended Over Camping Utensil NEWARK, DE, October 12, 2009. Zachary Christie him because the district bans knives regardless of the was so excited about joining the Cub Scouts and going possessor’s intent, age, or character. on campouts that he brought his favorite camping uten- “Zachary wears a suit and tie some days to school sil to school to use at lunch. The utensil is handy be- by his own choice because he takes school so seriously,” cause it can serve as a knife, fork, and spoon. But said Debbie Christie, Zachary’s mother. “He is not some school officials have decided that the 6-year-old boy vi- sort of threat to his classmates.” But George Evans, olated their zero-tolerance policy on weapons—which president of the school district’s board, defended the would include the “knife” part of the multipurpose decision. “There is no parent who wants to get a phone utensil—and have suspended him. He now faces call where they hear that their child no longer has two 45 days in the district’s reform school. “It just seems good seeing eyes because there was a scuffle and some- unfair,” Zachary said, while practicing writing his lower- one pulls out a knife,” he commented. case letters at home. Critics argue that zero-tolerance policies like the In response to shooting incidents in schools, many one that landed Zachary in hot water have led to in- districts have adopted zero-tolerance policies on the creased suspensions and expulsions, which results in possession of weapons on school grounds. In Zachary’s kids spending time in places like the street, where their case, officials felt they had no choice but to suspend behavior only gets worse. Inflexible policies can also lead to heavy punishment for minor infractions. Last year, a third grader in Delaware was expelled for a year because her grandmother had sent a birthday cake to school along with a knife to cut it. Zero-tolerance policies initially gave authorities more leeway in punishing students, but critics charged that they were being applied in a discriminatory manner against African-American children, who were more likely than white children to be suspended or expelled for committing the same offenses. As a result, many school districts have removed discretion in the application of the policies. Zachary himself is reluctant to go back to school. “I just think the other kids may tease me for being in trou- ble,” he said, and added, “but I think the rules are what Zachary Christie with the camping utensil that got him in trouble. is wrong, not me.”  CHAPTER Classical Conditioning Principles of Operant Psychology in the News, Conditioning Revisited Classical Conditioning in Real Life Operant Conditioning in Real Taking Psychology with You: Life Does Media Violence Make Operant Conditioning You Violent? Learning and the Mind Learning and Conditioning A re zero-tolerance policies justified? Should children who commit minor infractions be punished as severely as those who commit serious ones? If not, how should school administrators treat children who are disrup- tive or violent? Should schools expel them or are there alternatives? In the home, how should parents correct their children’s misbehavior? Is “a good spanking” the best recourse for parents, or should there be “zero tolerance” for parents who use any kind of corporal punishment? The debate over how to discipline children has been with us for a long time. It is part of a larger issue: How can we change unwanted, self-defeating, or dan- gerous behavior? Many people want to fix their own bad habits, of course, and they are forever trying to improve or fix other people’s behavior as well. We im- prison criminals, spank children, shout at spouses, and give the finger to a driver who cuts us off. On the positive side, we give children gold stars for good work, give parents bumper stickers that praise their children’s successes, give bonuses to employees, and give out trophies for top performance. Do any of these efforts get the results we hope for? Well, yes and no. Once you understand the laws of learning, you will realize that behavior, whether it’s your own or other people’s, can change for the better. And you will also understand why often it does not. Research on learning has been heavily influenced by behaviorism, the school of psychology that accounts for behavior in terms of observable acts and events, without reference to mental entities such as “mind” or “will” (see Chapter 1). Behaviorists focus on conditioning, which involves associations between environ- mental stimuli and responses. They have shown that two types of conditioning, classical conditioning and operant conditioning, can explain a great deal of be- havior both in animals and in people. But other approaches, including social- cognitive learning theories, hold that omitting mental processes from explanations of human learning is like omitting passion from descriptions of sex: 299 300 CHAPTER 9 Learning and Conditioning learning A relatively per- You may explain the form, but you miss its noticed something that most people would have manent change in behavior essence. To social-cognitive theorists, learning in- overlooked or dismissed as trivial. After a dog had (or behavioral potential) cludes not only changes in behavior but also been brought to the laboratory a few times, it due to experience. changes in thoughts, expectations, and knowledge, would start to salivate before the food was placed in which in turn influence behavior in a reciprocal, or its mouth. The sight or smell of the food, the dish behaviorism An ap- two-way, process. in which the food was kept, and even the sight of proach to psychology that emphasizes the study of As you read about the principles of conditioning the person who delivered the food were enough to observable behavior and and learning in this chapter, ask yourself what they start the dog’s mouth watering. These new salivary the role of the environ- can teach us about the use of punishment to control responses clearly were not inborn, so they must ment as a determinant of undesirable behavior. What happens when punish- have been acquired through experience. behavior. ment is used inappropriately? What is the best way At first, Pavlov treated the dog’s drooling as to modify other people’s behavior—and our own? just an annoying secretion. But he quickly realized conditioning A basic that his assistant had stumbled onto an important kind of learning that phenomenon, one that Pavlov came to believe was involves associations between environmental YOU are about to learn... the basis of most learning in human beings and other animals (Pavlov, 1927). He called that phe- stimuli and the how classical conditioning explains why a dog might nomenon a “conditional” reflex because it de- organism’s responses. salivate when it sees a lightbulb or hears a buzzer. pended on environmental conditions. Later, an four important features of classical conditioning. error in the translation of his writings transformed unconditioned stimu- “conditional” into “conditioned,” the word most lus (US) The classical- what is actually learned in classical conditioning. conditioning term for a commonly used today. stimulus that elicits a Pavlov soon dropped what he had been doing reflexive response in the absence of learning. Classical Conditioning and turned to the study of conditioned reflexes, to which he devoted the last three decades of his life. At the turn of the twentieth century, the great Why were his dogs salivating to things other than Russian physiologist Ivan Pavlov (1849–1936) was food? FIGURE 9.1 studying salivation in dogs as part of a research pro- Pavlov’s Method gram on digestion. One of his procedures was to The photo shows Ivan make a surgical opening in a dog’s cheek and insert New Reflexes from Old Pavlov (in the white a tube that conducted saliva away from the animal’s Pavlov initially speculated about what his dogs beard), flanked by his salivary gland so that the saliva could be measured. might be thinking and feeling when they drooled students and a canine To stimulate the reflexive flow of saliva, Pavlov before getting their food. Was the doggy equivalent subject. The drawing placed meat powder or other food in the dog’s of “Oh boy, this means chow time” going through depicts an apparatus mouth (see Figure 9.1). their minds? He soon decided, however, that such similar to the one he Pavlov was a truly dedicated scientific observer. speculation was pointless. Instead, he focused on used; saliva from a dog’s Many years later, as he lay dying, he even dictated analyzing the environment in which the condi- cheek flowed down a tube his sensations for posterity! And he instilled in his tioned reflex arose. and was measured by the students and assistants the same passion for detail. The original salivary reflex, according to movement of a needle on a revolving drum. During his salivation studies, one of the assistants Pavlov, consisted of an unconditioned stimulus (US), A B  CHAPTER 9 Learning and Conditioning 301 food in the dog’s mouth, and an unconditioned The procedure by which a neutral stimulus be- unconditioned response (UR), salivation. By an unconditioned comes a conditioned stimulus eventually became response (UR) The stimulus, Pavlov meant an event or thing that elicits known as classical conditioning, and is sometimes classical-conditioning term a response automatically or reflexively. By an un- also called Pavlovian or respondent conditioning. for a reflexive response elicited by a stimulus in conditioned response, he meant the response that is Pavlov and his students went on to show that all the absence of learning. automatically produced: sorts of things can become conditioned stimuli for salivation if they are paired with food: the ticking of conditioned stimulus a metronome, the musical tone of a bell, the vibrat- (CS) The classical- ing sound of a buzzer, a touch on the leg, even a conditioning term for an pinprick or an electric shock. And since Pavlov’s initially neutral stimulus day, many automatic, involuntary responses besides that comes to elicit a salivation have been classically conditioned, includ- conditioned response after being associated with an ing heartbeat, stomach secretions, blood pressure, US unconditioned stimulus. reflexive movements, blinking, and muscle contrac- tions. In the laboratory, the optimal interval be- conditioned response tween the presentation of the neutral stimulus and (CR) The classical- UR the presentation of the US is often quite short, conditioning term for a sometimes less than a second. response that is elicited by a conditioned stimulus; it occurs after the Learning occurs, said Pavlov, when a neutral Principles of Classical conditioned stimulus is stimulus (one that does not yet produce a particular associated with an uncon- response, such as salivation) is regularly paired with Conditioning ditioned stimulus. an unconditioned stimulus: Classical conditioning occurs in all species, from one-celled amoebas to Homo sapiens. Let us look classical conditioning The process by which a more closely at some important features of this previously neutral stimulus process: extinction, higher-order conditioning, and acquires the capacity to stimulus generalization and discrimination. elicit a response through association with a stimulus Extinction Conditioned responses do not nec- that already elicits a simi- Neutral US essarily last forever. If, after conditioning, the con- lar or related response. stimulus Also called Pavlovian or ditioned stimulus is repeatedly presented without respondent conditioning. the unconditioned stimulus, the conditioned re- sponse eventually disappears and extinction is said extinction The weaken- UR to have occurred (see Figure 9.2 on the next page). ing and eventual disap- Suppose that you train your dog Milo to salivate to pearance of a learned the sound of a bell, but then you ring the bell every response; in classical The neutral stimulus then becomes a five minutes and do not follow it with food. Milo conditioning, it occurs conditioned stimulus (CS), which elicits a learned or will salivate less and less to the bell and will soon when the conditioned conditioned response (CR) that is usually similar or stop salivating altogether; salivation will have been stimulus is no longer related to the original, unlearned one. In Pavlov’s extinguished. Extinction is not the same as unlearn- paired with the uncondi- laboratory, the sight of the food dish, which had not tioned stimulus. ing or forgetting, however. If you come back the previously elicited salivation, became a CS for next day and ring the bell, Milo may salivate again spontaneous recovery salivation: for a few trials, although the response will probably The reappearance of a be weaker. The reappearance of the response, learned response after its called spontaneous recovery, explains why com- apparent extinction. pletely eliminating a conditioned response often re- quires more than one extinction session. higher-order condi- tioning In classical conditioning, a procedure Higher-Order Conditioning Sometimes a neu- in which a neutral stimu- CS tral stimulus can become a conditioned stimulus by lus becomes a conditioned being paired with an already-established CS, a pro- stimulus through associa- cedure known as higher-order conditioning. Say tion with an already estab- Milo has learned to salivate to the sight of his food lished conditioned CR dish. Now you flash a bright light before presenting stimulus. 302 CHAPTER 9 Learning and Conditioning 14 14 conditioning, in other words, may contribute to the formation of prejudices. 12 12 Drops of saliva to CS Drops of saliva to CS 10 10 Stimulus Generalization and Discrimina- 8 8 tion After a stimulus becomes a conditioned stim- ulus for some response, other, similar stimuli may 6 6 produce a similar reaction—a phenomenon known 4 4 as stimulus generalization. If you condition your 2 2 patient pooch Milo to salivate to middle C on the piano, Milo may also salivate to D, which is one 0 4 8 12 16 0 2 4 6 8 10 tone above C, even though you did not pair D with food. Stimulus generalization is described nicely by Acquisition trials Extinction trials an old English proverb: “He who hath been bitten (CS paired with US) (CS presented alone) by a snake fears a rope.” The mirror image of stimulus generalization is FIGURE 9.2 stimulus discrimination, in which different responses Acquisition and Extinction of a Salivary Response A neutral stimulus that is consistently followed by an unconditioned stimulus for salivation are made to stimuli that resemble the conditioned will become a conditioned stimulus for salivation (left). But when this conditioned stimulus stimulus in some way. Suppose that you have condi- is then repeatedly presented without the unconditioned stimulus, the conditioned salivary tioned Milo to salivate to middle C on the piano by response will weaken and eventually disappear (right); it has been extinguished. repeatedly pairing the sound with food. Now you play middle C on a guitar, without following it by food (but you continue to follow C on the piano by stimulus generaliza- the dish. With repeated pairings of the light and food). Eventually, Milo will learn to salivate to a C tion After conditioning, the dish, Milo may learn to salivate to the light. on the piano and not to salivate to the same note on the tendency to respond The procedure for higher-order conditioning is il- the guitar; that is, he will discriminate between the to a stimulus that resem- lustrated in Figure 9.3. two sounds. If you keep at this long enough, you bles one involved in the Higher-order conditioning may explain why could train Milo to be a pretty discriminating original conditioning; in some words trigger emotional responses in us— drooler! classical conditioning, it occurs when a stimulus why they can inflame us to anger or evoke warm, that resembles the CS sentimental feelings. When words are paired with What Is Actually Learned elicits the CR. objects or other words that already elicit some emotional response, they too may come to elicit in Classical Conditioning? stimulus discrimina- that response (Staats & Staats, 1957). A child may For classical conditioning to be most effective, the tion The tendency to learn a positive response to the word birthday stimulus to be conditioned should precede the un- respond differently to two because of its association with gifts and attention. conditioned stimulus rather than follow it or occur or more similar stimuli; in Conversely, the child may learn a negative response simultaneously with it. This makes sense because, classical conditioning, it to ethnic or national labels if the labels are paired in classical conditioning, the conditioned stimulus occurs when a stimulus with words that the child has already learned are becomes a signal for the unconditioned stimulus. similar to the CS fails to disagreeable, such as dumb or dirty. Higher-order Classical conditioning is in fact an evolutionary evoke the CR. CS Neutral CS CS stimulus CR CR CR FIGURE 9.3 Higher-Order Conditioning In this illustration of higher-order conditioning, the food dish is a previously conditioned stimu- lus for salivation (left). When the light, a neutral stimulus, is paired with the dish (center), the light also becomes a conditioned stimulus for salivation (right).  CHAPTER 9 Learning and Conditioning 303 Get Involved! Conditioning an Eye-Blink Response Try out your behavioral skills by conditioning an eye-blink response in a willing friend, using classical- conditioning procedures. You will need a drinking straw and something to make a ringing sound; a spoon tapped on a water glass works well. Tell your friend that you are going to use the straw to blow air in his or her eye, but do not say why. Immediately before each puff of air, make the ringing sound. Repeat this procedure ten times. Then make the ringing sound but don’t puff. Your friend will probably blink anyway, and may continue to do so for one or two more repetitions of the sound before the response extinguishes. Can you identify the US, the UR, the CS, and the CR in this exercise? adaptation, one that enables the organism to antici- getting food. Think of it this way: If every phone pate and prepare for a biologically important event call you got brought bad news that made your heart that is about to happen. In Pavlov’s studies, for in- race, your heart might soon start pounding every stance, a bell, buzzer, or other stimulus was a signal time the phone rang—a conditioned response. that meat was coming, and the dog’s salivation was Ordinarily, though, upsetting calls occur randomly preparation for digesting food. Today, therefore, among a far greater number of routine ones. The many psychologists contend that what an animal or ringtone may sometimes be paired with a racing person actually learns in classical conditioning is heart, but it doesn’t always signal disaster, so no not merely an association between two paired stim- conditioned heart-rate response occurs. uli that occur close together in time, but rather Rescorla concluded that “Pavlovian conditioning information conveyed by one stimulus about an- is not a stupid process by which the organism willy- other: “If a tone sounds, food is likely to follow.” nilly forms associations between any two stimuli that This view is supported by the research of happen to co-occur. Rather, the organism is better Robert Rescorla (1988), who showed, in a series of seen as an information seeker using logical and per- imaginative studies, that the mere pairing of an un- ceptual relations among events, along with its own conditioned stimulus and a neutral stimulus is not preconceptions, to form a sophisticated representa- enough to produce learning. To become a condi- tion of its world.” Not all learning theorists agree; an tioned stimulus, the neutral stimulus must reliably orthodox behaviorist would say that it is silly to talk signal, or predict, the unconditioned stimulus. If about the preconceptions of a rat. The important Explore food occurs just as often without a preceding tone as point, however, is that concepts such as “information Three Stages of with it, the tone is unlikely to become a conditioned seeking,” “preconceptions,” and “representations of Classical Condi- stimulus for salivation, because the tone does not the world” open the door to a more cognitive view of tioning on provide any information about the probability of classical conditioning. Explore mypsychlab.com Study and Quick Quiz Review on mypsychlab.com Classical-conditioning terms can be hard to learn, so be sure to take this quiz before going on. A. Name the unconditioned stimulus, unconditioned response, conditioned stimulus, and conditioned re- sponse in these two situations. 1. Five-year-old Samantha is watching a storm from her window. A huge bolt of lightning is followed by a tremendous thunderclap, and Samantha jumps at the noise. This happens several more times. There is a brief lull and then another lightning bolt. Samantha jumps in response to the bolt. 2. Gregory’s mouth waters whenever he eats anything with lemon in it. One day, while reading an ad that shows a big glass of lemonade, Gregory finds that his mouth has started to water. B. In the view of many learning theorists, pairing a neutral and unconditioned stimulus is not enough to pro- duce classical conditioning; the neutral stimulus must __________ the unconditioned stimulus. Answers: vation elicited by the picture B. signal or predict ning 2. US ⫽ the taste of lemon; UR ⫽ salivation elicited by the taste of lemon; CS ⫽ the picture of a glass of lemonade; CR ⫽ sali- A. 1. US ⫽ the thunderclap; UR ⫽ jumping elicited by the noise; CS ⫽ the sight of the lightning; CR ⫽ jumping elicited by the light- 304 CHAPTER 9 Learning and Conditioning YOU are about to learn... thinks you’ll like, with good-looking people, with idyllic scenery, or with celebrities you admire or why advertisers often include pleasant music and think are funny. In classical-conditioning terms, the gorgeous scenery in ads for their products. music, attractive person, or celebrity is an uncondi- tioned stimulus for internal responses associated how classical conditioning might explain your irrational fear of heights or mice. with pleasure, and the advertiser hopes that the product in the ad will become a conditioned stimu- how you might be conditioned to like certain tastes and lus, evoking similar responses in you. odors and be turned off by others. how sitting in a doctor’s office can make you feel sick Learning to Fear and placebos can make you feel better. Positive emotions are not the only ones that can be how technology is helping researchers study the classically conditioned; so can dislikes and fears. A biological basis of classical conditioning. person can learn to fear just about anything if it is paired with something that elicits pain, surprise, or Classical Conditioning embarrassment. Human beings, however, are bio- logically primed to acquire some kinds of fears in Real Life more readily than others. It is far easier to establish a conditioned fear of spiders, snakes, and heights If a dog can learn to salivate to the ringing of a bell, than of butterflies, flowers, and toasters. The for- so can you. In fact, you probably have learned to mer can be dangerous to your health, so in the salivate to the sound of a lunch bell, the phrase hot process of evolution, human beings acquired a ten- fudge sundae, and “mouth-watering” pictures of dency to learn quickly to be wary of them and to re- food. But classical conditioning affects us every day tain this fear (LoBue & DeLoache, 2008; Öhman in many other ways. & Mineka, 2001). Some theorists believe that evo- One of the first psychologists to recognize the lution has also instilled in humans a readiness to real-life implications of Pavlovian theory was John learn to fear unfamiliar members of ethnic groups B. Watson, who founded American behaviorism other than their own, and that this tendency too re- and enthusiastically promoted Pavlov’s ideas. Wat- sists extinction and may contribute to the emo- son believed that the whole rich array of human tional underpinnings of prejudice (Navarrete et al., emotion and behavior could be accounted for by 2009; Olsson et al., 2005). conditioning principles. He even suggested that we learn to love another person when that person is paired with stroking and cuddling. Wat- The Birth of a Phobia When fear of an object son was wrong about love, which is a lot or situation becomes irrational and interferes with more complicated than he thought (see normal activities, it qualifies as a phobia (see Chapter 14). But he was right about the Chapter 11). To demonstrate how a phobia might power of classical conditioning to affect be learned, John Watson and Rosalie Rayner our emotions, preferences, and tastes. (1920/2000) deliberately established a rat phobia in an 11-month-old boy named Albert. Their goal was to demonstrate how an inborn reaction of fear Learning to Like could transfer to a wide range of stimuli; today we Classical conditioning plays a big role in call this stimulus generalization. They also wanted our emotional responses to objects, to demonstrate that adult emotional responses, people, symbols, events, and places. It such as specific fears, could originate in early child- can explain why sentimental feelings hood. The research procedures that Watson and sweep over us when we see a school Rayner used had some flaws, and for ethical rea- mascot, a national flag, or the logo of sons, no psychologist today would attempt to do the Olympic games. These objects have such a thing to a child. Nevertheless, the study’s been associated in the past with positive main conclusion, that fears can be conditioned, is feelings. still well accepted. Many advertising techniques take “Little Albert” was a placid child who rarely advantage of classical conditioning’s cried. (Watson and Rayner deliberately chose such Why do most people fear snakes, and role in emotional responses. When you a child because they thought their demonstration why do some even develop a snake see ads, notice how many of them pair a would do him relatively little harm.) When Watson phobia? product with music the advertiser and Rayner gave Albert a live, furry rat to play with,  CHAPTER 9 Learning and Conditioning 305 US Neutral US CS stimulus UR UR CR FIGURE 9.4 The Creation of a Fear In the Little Albert study, noise from a hammer striking a steel bar was an unconditioned stimulus for fear (left). When a white rat, a neutral stimulus, was paired with the noise (center), the rat then became a conditioned stimulus for fear (right). he showed no fear; in fact, he was delighted. The stimulus for fear (see Figure 9.4). Tests done a few counterconditioning same was true when they showed him a variety of days later showed that Albert’s fear had generalized In classical conditioning, other objects, including a rabbit and some cotton to other hairy or furry objects, including a white the process of pairing a wool. However, like most children, Albert was rabbit, cotton wool, a Santa Claus mask, and even conditioned stimulus with a stimulus that elicits a innately afraid of loud noises. When the re- John Watson’s hair. Explore response that is incompat- searchers made a loud noise behind his head by Unfortunately, Watson and Rayner lost access ible with an unwanted striking a steel bar with a hammer, he would jump to Little Albert, so we do not know how long the conditioned response. and fall sideways onto the mattress where he was child’s fears lasted. Further, because the study ended sitting. The noise made by the hammer was an early, Watson and Rayner had no opportunity to unconditioned stimulus for the unconditioned reverse the conditioning. However, Watson and response of fear. Mary Cover Jones did reverse another child’s condi- Explore Having established that Albert liked rats, Wat- tioned fear—one that was, as Watson put it, “home- Classical Condi- tioning of Little son and Rayner set about teaching him to fear grown” rather than psychologist-induced ( Jones, Albert on them. Again they offered him a rat, but this time, as 1924). A 3-year-old named Peter was deathly afraid mypsychlab.com he reached for it, one of the researchers struck the of rabbits. Watson and Jones eliminated his fear steel bar. Startled, Albert fell onto the mattress. A with a method called counterconditioning, in which week later, the researchers repeated this procedure a conditioned stimulus is paired with some other several times. Albert began to whimper and trem- stimulus that elicits a response incompatible with ble. Finally, they held out the rat to him without the unwanted response (see Figure 9.5). making the noise. Albert fell over, cried, and At first, the researchers kept the rabbit some crawled away so quickly that he almost reached the distance from Peter, so that his fear would remain edge of the table he was sitting on before an adult at a low level. Otherwise, Peter might have learned caught him; the rat had become a conditioned to fear milk and crackers! Then gradually, over US CS CS US CS UR CR UR New CR FIGURE 9.5 The Counterconditioning of a Fear Three-year-old Peter had acquired a conditioned response of fear of rabbits. To countercondition this fear, the researchers paired a rabbit (the CS) with a snack of milk and crackers (a US), which produced pleasant feelings that were incompatible with the condi- tioned response of fear. Eventually, Peter felt as comfortable with the rabbit as with the crackers. 306 CHAPTER 9 Learning and Conditioning several days, they brought the rabbit closer and closer. Eventually Peter learned to like rabbits and Peter was even able to sit with the rabbit in his lap, playing with it with one hand while he ate with the other. A variation of this procedure, called systematic desensitization, was later devised for treat- ing phobias in adults (see Chapter 12). Biology and Conditioned Fears Researchers today are exploring the biological basis of fear con- ditioning and fear extinction. The acquisition of a conditioned fear appears to involve a receptor in the amygdala for the neurotransmitter glutamate. Giv- ing rats a drug that blocks this receptor prevents ex- tinction of a conditioned fear, whereas giving a drug that enhances the receptor’s activity speeds up ex- tinction (Walker et al., 2002). Inspired by these re- Whether we say “yuck” or “yum” to a food may depend sults, researchers set out to learn whether the on a past experience involving classical conditioning. receptor-enhancing drug (which is safe in humans) could help people with a phobic fear of heights (Davis et al., 2005). Using a double-blind proce- odors by pairing them with drugs that cause nausea dure, they gave the drug to 15 such people and a or other unpleasant symptoms. One research team placebo to 15 others. The participants then under- trained slugs to associate the smell of carrots, which went two therapy sessions in which they donned vir- slugs normally like, with a bitter-tasting chemical tual reality goggles and “rode” a glass elevator to they detest. Soon the slugs were avoiding the smell progressively higher floors in a virtual hotel—an in- of carrots. The researchers then demonstrated credibly scary thing to do if you’re terrified of higher-order conditioning by pairing the smell of heights! They could also “walk” out on a bridge and carrots with the smell of potato. Sure enough, the look down on a fountain in the hotel lobby. During slugs began to avoid the smell of potato as well each session, and again at one-week and three- (Sahley, Rudy, & Gelperin, 1981). month follow-up sessions, the participants rated Many people have learned to dislike a food their discomfort at each “floor.” Combining the after eating it and then falling ill, even when the therapy with the drug reduced symptoms far more two events were unrelated. The food, previously a than combining it with the placebo. Further, in their neutral stimulus, becomes a conditioned stimulus everyday lives, people who got the drug were less for nausea or other symptoms produced by the ill- likely than the control subjects to avoid heights. ness. Psychologist Martin Seligman once told how Genetic differences might explain why some he himself was conditioned to hate béarnaise sauce. people are more likely than others to become anx- One night, shortly after he and his wife ate a deli- ious and fearful. In a study done in Sweden, re- cious filet mignon with béarnaise sauce, he came searchers conditioned university students to startle down with the flu. Naturally, he felt wretched. His in response to pictures of faces. Only those students misery had nothing to do with the béarnaise sauce, who had a particular gene associated with reactivity of course, yet the next time he tried it, he found to in the amygdala acquired the conditioned startle re- his annoyance that he disliked the taste (Seligman sponse. And those students who carried a gene as- & Hager, 1972). sociated with impaired cognitive control in the Notice that, unlike conditioning in the labora- prefrontal cortex showed resistance to extinction of tory, Seligman’s aversion to the sauce occurred after the response (Lonsdorf et al., 2009). Such research only one pairing of the sauce with illness and with a helps us to understand the biological mechanisms considerable delay between the conditioned and that underlie our innate and conditioned fears. unconditioned stimuli. Moreover, Seligman’s wife did not become a conditioned stimulus for nausea, and neither did his dinner plate or the waiter, even Accounting for Taste though they also had been paired with illness. Classical conditioning can also explain learned re- Why? In earlier work with rats, John Garcia and actions to many foods and odors. In the laboratory, Robert Koelling (1966) had provided the answer: researchers have taught animals to dislike foods or the existence of a greater biological readiness to  CHAPTER 9 Learning and Conditioning 307 associate sickness with taste than with sights or sounds. Like the tendency to acquire certain fears, this biological tendency probably evolved because it enhanced survival. Eating bad food, after all, is more likely to be followed by illness than are sights or sounds. Psychologists have taken advantage of this phe- nomenon to develop humane ways of discouraging predators from preying on livestock, using condi- tioned taste aversions instead of traps and poisons. In one classic study, researchers laced sheep meat with a nausea-inducing chemical. Coyotes and wolves fell for the bait, and as a result they devel- oped a conditioned aversion to sheep (Gustavson et al., 1974). Similar techniques have been used to deter raccoons from killing chickens, and ravens and crows from eating crane eggs (Garcia & Gus- tavson, 1997). Reacting to Medical Treatments Because of classical conditioning, medical treat- ments can create unexpected misery, because reac- tions to treatment may generalize to stimuli that are entirely unrelated to the treatment itself. A par- The anxiety that many people feel about having blood ticular problem for cancer patients is that the nau- drawn can generalize to the nurse, the room, the sight of sea and vomiting resulting from chemotherapy needles.... often generalize to the place where the therapy takes place, the waiting room, the sound of a nurse’s affect the brain in much the same way as real treat- voice, or the smell of rubbing alcohol. The drug ments do (see Chapter 6). Cognitive psychologists treatment is an unconditioned stimulus for nausea emphasize the role of expectations of getting better, and vomiting, and through association, the other which may reduce anxiety and thus boost the im- previously neutral stimuli become conditioned mune system, or simply encourage people to cope stimuli for these responses. Even mental images of better with their symptoms. But behaviorists argue the sights and smells of the clinic can become con- that the doctor’s white coat, the doctor’s office, and ditioned stimuli for nausea (Dadds et al., 1997; pills or injections all become conditioned stimuli Redd et al., 1993). for relief from symptoms because these stimuli Some cancer patients also acquire a classically have been associated in the past with real drugs conditioned anxiety response to anything associ- (Ader, 2000). The real drugs are the unconditioned ated with their chemotherapy. In one study, pa- stimuli, and the relief they bring is the uncondi- tients who drank lemon-lime Kool-Aid before their tioned response. Placebos acquire the ability to therapy sessions developed an anxiety response to elicit similar reactions, thereby becoming condi- the drink—an example of higher-order condition- tioned stimuli. ing. They continued to feel anxious even when the The expectancy explanation of placebo effects drink was offered in their homes rather than at the and the classical-conditioning explanation are not clinic ( Jacobsen et al., 1995). mutually exclusive (Kirsch, 2004; Stewart-Williams Conversely, patients may have reduced pain and & Podd, 2004). As we saw earlier, many researchers anxiety when they receive placebos, pills and injec- now accept the view that classical conditioning it- tions that have no active ingredients or treatments self involves the expectation that the conditioned that have no direct physical effect on the problem. stimulus will be followed by the unconditioned Placebos can be amazingly powerful, especially stimulus. Thus, at least some classically condi- when they take the form of an injection, a large pill, tioned placebo effects may involve the patient’s or a pill with a brand name (Benedetti & Levi- expectations. In fact, the patient’s previous condi- Montalcini, 2001). Why do they work? Biological tioning history may be what created those expecta- psychologists have shown that placebos can actually tions to begin with. 308 CHAPTER 9 Learning and Conditioning Study and Review on mypsychlab.com Quick Quiz We hope you have not acquired a classically conditioned fear of quizzes. A. See whether you can supply the correct term to describe the outcome in each of these situations. 1. After a child learns to fear spiders, he also responds with fear to ants, beetles, and other crawling bugs. 2. A toddler is afraid of the bath, so her father puts just a little water in the tub and gives the child a lol- lipop to suck on while she is being washed. Soon the little girl loses her fear of the bath. 3. A factory worker’s mouth waters whenever a noontime bell signals the beginning of his lunch break. One day, the bell goes haywire and rings every half hour. By the end of the day, the worker has stopped sali- vating to the bell. B. A boy who gets weekly allergy shots starts to feel anxious as soon as he enters the doctor’s waiting room. What is the behavioral explanation? Answers: conditioned stimulus for the anxiety and discomfort provoked by the shots. A. 1. stimulus generalization 2. counterconditioning 3. extinction B. The sight and smells of the waiting room have become a YOU are about to learn... In classical conditioning, it does not matter whether an animal’s or person’s behavior has consequences. how the consequences of your actions affect your In Pavlov’s procedure, the dog learned an associa- future behavior. tion between two events that were not under its control (e.g., a tone and the delivery of food), and what praising a child and quitting your nagging have in common. the animal got food whether or not it salivated. But in operant conditioning, the organism’s response (such as the little girl’s sobbing) operates or produces Operant Conditioning effects on the environment. These effects, in turn, influence whether the response will occur again. At the end of the nineteenth century, in the first Classical conditioning and operant condition- known scientific study of anger, G. Stanley Hall ing also tend to differ in the types of responses they (1899) asked people to describe angry episodes they had experienced or observed. One person told of a 3-year-old girl who broke out in seemingly uncon- trollable sobs when she was kept home from a ride. In the middle of her outburst, the child suddenly stopped and asked her nanny in a perfectly calm voice if her father was in. Told no, and realizing that he was not around to put a stop to her tantrum, she immediately resumed her sobbing. Children, of course, cry for many valid rea- sons—pain, discomfort, fear, illness, fatigue—and these cries deserve an adult’s sympathy and atten- tion. The child in Hall’s study, however, was crying because she had learned from prior experience that an outburst of sobbing would pay off by bringing her attention and possibly the ride she wanted. Her operant conditioning The tantrum illustrates one of the most basic laws of process by which a re- learning: Behavior becomes more likely or less likely de- sponse becomes more pending on its consequences. likely to occur or less so, This principle is at the heart of operant condi- depending on its conse- tioning (also called instrumental conditioning), the quences. second type of conditioning studied by behaviorists.  CHAPTER 9 Learning and Conditioning 309 involve. In classical conditioning, the response is chop off your plate, her begging is likely to in- typically reflexive, an automatic reaction to some- crease: thing happening in the environment, such as the sight of food or the sound of a bell. Generally, re- sponses in operant conditioning are complex and are not reflexive—for instance, riding a bicycle, writing a letter, climbing a mountain,... or throw- ing a tantrum. Response becomes more likely The Birth of Radical Behaviorism Reinforcers are roughly equivalent to rewards, Operant conditioning has been studied since the and many psychologists use reward and reinforcer as start of the twentieth century, although it was not approximate synonyms. However, strict behavior- called that until later. Edward Thorndike (1898), ists avoid the word reward because it implies that then a young doctoral candidate, set the stage by something has been earned that results in happiness observing cats as they tried to escape from a com- or satisfaction. To a behaviorist, a stimulus is a rein- plex “puzzle box” to reach a scrap of fish located forcer if it strengthens the preceding behavior, just outside the box. At first, the cat would scratch, whether or not the organism experiences pleasure bite, or swat at parts of the box in an unorganized or a positive emotion. Conversely, no matter how way. Then, after a few minutes, it would chance on pleasurable a reward is, it is not a reinforcer if it the successful response (loosening a bolt, pulling a does not increase the likelihood of a response. It’s string, or hitting a button) and rush out to get the great to get a paycheck, but if you get paid regard- reward. Placed in the box again, the cat now took a less of the effort you put into your work, the money little less time to escape, and after several trials, the will not reinforce “hard-work behavior.” animal immediately made the correct response. Ac- cording to Thorndike, this response had been “stamped in” by the satisfying result of getting the 2 Punishment weakens the response or makes it less likely to recur. Any aversive (unpleasant) stimulus or event may be a punisher. If your dog food. In contrast, annoying or unsatisfying results begs for a lamb chop off your plate, and you lightly “stamped out” behavior. Behavior, said Thorndike, swat her nose and shout “No,” her begging is likely is controlled by its consequences. to decrease—as long as you don’t feel guilty and This general principle was elaborated and then give her the lamb chop anyway: extended to more complex forms of behavior by B. F. (Burrhus Frederic) Skinner (1904–1990). Skin- ner called his approach “radical behaviorism” to distinguish it from the behaviorism of John Wat- son, who emphasized classical conditioning. Skin- ner argued that to understand behavior we should “No!” Response focus on the external causes of an action and the ac- becomes tion’s consequences. He avoided terms that less likely Thorndike used, such as “satisfying” and “annoy- ing,” which reflect assumptions about what an Parents, employers, and governments resort to organism feels and wants. To explain behavior, reinforcers and punishers all the time—to get kids reinforcement The he said, we should look outside the individual, not process by which a stimu- to behave well, employees to work hard, and con- inside. lus or event strengthens or stituents to pay taxes—but they do not always use them effectively. Often, they wait too long to de- increases the probability of the response that it The Consequences of Behavior liver the reinforcer or punisher. In general, the follows. sooner a consequence follows a response, the In Skinner’s analysis, which has inspired an greater its effect; you are likely to respond more re- immense body of research, a response (“operant”) punishment The liably when you do not have to wait ages for a can be influenced by two types of consequences: process by which a stimu- grade, a smile, or a compliment. When there is a lus or event weakens or 1 Reinforcement strengthens the response or makes it more likely to recur. When your dog begs for food at the table, and you give her the lamb delay, other responses occur in the interval, and the connection between the desired or undesired response and the consequence may not be made. reduces the probability of the response that it follows. 310 CHAPTER 9 Learning and Conditioning primary reinforcer A Primary and Secondary Reinforcers and stimulus that is inherently Punishers Food, water, light stroking of the skin, reinforcing, typically satis- fying a physiological need; and a comfortable air temperature are naturally re- A+ inforcing because they satisfy biological needs. an example is food. Positive They are therefore known as primary reinforcers. reinforcer: primary punisher A Similarly, pain and extreme heat or cold are inher- Good grade stimulus that is inherently ently punishing and are therefore known as primary punishing; an example is punishers. Primary reinforcers and punishers can Behavior: Result: electric shock. be powerful, but they have some drawbacks, both in Studying Studying real life and in research. For one thing, a primary increases secondary reinforcer reinforcer may be ineffective if an animal or person A stimulus that has is not in a deprived state; a glass of water is not Negative acquired reinforcing prop- much of a reward if you just drank three glasses. reinforcer: erties through association Also, for obvious ethical reasons, psychologists Nagging with other reinforcers. ceases cannot go around using primary punishers (say, by hitting the people in their study) or taking secondary punisher A away primary reinforcers (say, by starving their stimulus that has acquired Likewise, negative reinforcement occurs when volunteers). punishing properties taking a pill eliminates your pain or when you take a through association with Fortunately, behavior can be controlled just as certain route across campus to avoid a rude person. other punishers. effectively by secondary reinforcers and secondary The positive–negative distinction can also be punishers, which are learned. Money, praise, ap- applied to punishment: Something unpleasant may positive reinforce- plause, good grades, awards, and gold stars are occur following some behavior (positive punish- ment A reinforcement common secondary reinforcers. Criticism, demer- ment), or something pleasant may be removed (nega- procedure in which a its, scolding, fines, and bad grades are common sec- tive punishment). For example, if your friends tease response is followed by ondary punishers. Most behaviorists believe that the presentation of, or you for being an egghead (positive punishment) or secondary reinforcers and punishers acquire their increase in intensity of, a if studying makes you lose time with your friends ability to influence behavior by being paired with reinforcing stimulus; as (negative punishment), you may stop studying: primary reinforcers and punishers. (If that reminds a result, the response you of classical conditioning, reinforce your excel- becomes stronger or more lent thinking with a pat on the head! Indeed, sec- likely to occur. ondary reinforcers and punishers are often called negative reinforce- conditioned reinforcers and punishers.) As a second- ment A reinforcement ary reinforcer, money has considerable power over procedure in which a most people’s behavior because it can be exchanged Positive response is followed by for primary reinforcers such as food and shelter. It punishment: Ridicule by the removal, delay, or is also associated with other secondary reinforcers, friends decrease in intensity of an such as praise and respect. unpleasant stimulus; as Behavior: Result: a result, the response Positive and Negative Reinforcers and Studying Studying becomes stronger or more decreases Punishers In our example of the begging dog, likely to occur. something pleasant (getting the lamb chop) followed the dog’s begging response, so the re- Negative punishment: sponse increased. Similarly, if you get a good grade Loss of time after studying, your efforts to study are likely to with friends continue or increase. This kind of process, in which a pleasant consequence makes a response more likely, is known as positive reinforcement. But The distinction between positive and negative there is another type of reinforcement, negative reinforcement and punishment has been a source of reinforcement, which involves the removal of confusion for generations of students, turning something unpleasant. Negative reinforcement oc- many strong minds to mush. You will master these curs when you escape from something aversive or terms more quickly if you understand that “posi- avoid it by preventing it from ever occurring. For tive” and “negative” have nothing to do with example, if someone nags you to study but stops “good” or “bad.” They refer to whether something nagging when you comply, your studying is likely is given or taken away. In the case of reinforcement, to increase because you will then avoid the think of a positive reinforcer as something that nagging: is added or obtained (imagine a plus sign) and a  CHAPTER 9 Learning and Conditioning 311 negative reinforcer as avoidance of, or escape from, with negative reinforcement, you escape from it or something unpleasant (imagine a minus sign). In ei- avoid it. To keep these terms straight, remember ther case, a response becomes more likely. Do you recall that punishment, whether positive or negative, what happened when Little Albert learned to fear decreases the likelihood of a response; and reinforce- rats through a process of classical conditioning? ment, whether positive or negative, increases it. In After he acquired this fear, crawling away was nega- real life, punishment and negative reinforcement tively reinforced by escape from the now-fearsome often go hand in hand. If you use a chain collar to rodent. The negative reinforcement that results teach your dog to heel, a brief tug on the collar pun- from escaping or avoiding something unpleasant ishes the act of walking; release of the collar nega- explains why so many fears are long-lasting. When tively reinforces the act of standing by your side. you avoid a feared object or situation, you also cut You can positively reinforce your studying of off all opportunities to extinguish your fear. this material by taking a short break. As you master Listen to the Podcast on Understandably, people often confuse negative the material, a decrease in your anxiety will nega- Punishment and reinforcement with positive punishment, because tively reinforce studying. But we hope you won’t Reinforcement both involve an unpleasant stimulus. With punish- punish your efforts by telling yourself “I’ll never on ment, you are subjected to the unpleasant stimulus; get it” or “It’s too hard”! Listen mypsychlab.com Study and Quick Quiz Review on mypsychlab.com What kind of consequence will follow if you can’t answer these questions? 1. A child nags her father for a cookie; he keeps refusing. Finally, unable to stand the nagging any longer, he hands over the cookie. For him, the ending of the child’s pleading is a. For the child, the cookie is a. 2. An able-bodied driver is careful not to park in a handicapped space anymore after paying a large fine for doing so. The loss of money is a. 3. Identify which of the following are commonly used as secondary reinforcers: quarters spilling from a slot machine, a winner’s blue ribbon, a piece of candy, an A on an exam, frequent-flyer miles. 4. During late afternoon “happy hours,” bars and restaurants sell drinks at a reduced price and appetizers are often free. What undesirable behavior may be rewarded by this practice? Answers: mosphere all reinforce heavy alcohol consumption just before rush hour, thus possibly contributing to binge drinking and drunk driving. away) 3. All but the candy are secondary reinforcers. 4. One possible answer: The reduced prices, free appetizers, and cheerful at- 1. negative reinforcer; positive reinforcer 2. punisher—or more precisely, a negative punisher (because something desirable was taken YOU are about to learn... with a device that delivers a reinforcer, usually food, when an animal makes a desired response, or a pun- four important features of operant conditioning. isher, such as a brief shock, when the animal makes an undesired response (see Figure 9.6). In modern why it’s not always a good idea to reinforce a response every time it occurs. versions, a computer records responses and charts the rate of responding and cumulative responses how operant principles help explain superstitious across time. behavior. Early in his career, Skinner (1938) used the what it means to “shape” behavior. Skinner box for a classic demonstration of operant some biological limits on operant conditioning. conditioning. A rat that had previously learned to eat from the pellet-releasing device was placed in the box. The animal proceeded to scurry about the Principles of Operant box, sniffing here and there, and randomly touch- Conditioning ing parts of the floor and walls. Quite by accident, it happened to press a lever mounted on one wall, and Thousands of operant conditioning studies have immediately a pellet of tasty rat food fell into the been done, many using animals. A favorite experi- food dish. The rat continued its movements and mental tool is the Skinner box, a chamber equipped again happened to press the bar, causing another 312 CHAPTER 9 Learning and Conditioning FIGURE 9.6 The Skinner Box When a rat in a Skinner box presses a bar, a food pellet or drop of water is automatically released. The photo shows Skinner at work on one of the boxes. Light Bar Water Food tray extinction The weaken- pellet to fall into the dish. With additional repeti- learned to make some extraordinary discrimina- ing and eventual disap- pearance of a learned tions of bar pressing followed by food, the animal tions. They even learned to discriminate between response; in operant con- began to behave less randomly and to press the bar two paintings by different artists, such as Vincent ditioning, it occurs when more consistently. Eventually, Skinner had the rat Van Gogh and Marc Chagall (Watanabe, 2001). a response is no longer pressing the bar as fast as it could. And then, when presented with a new pair of paint- followed by a reinforcer. ings by those same two artists, they were able to tell Extinction In operant conditioning, as in classi- the difference between them! stimulus generaliza- cal, extinction is a procedure that causes a previ- Sometimes an animal or person learns to re- tion In operant condition- ously learned response to stop. In operant spond to a stimulus only when some other stimulus, ing, the tendency for a called a discriminative stimulus, is present. The dis- conditioning, extinction takes place when the rein- response that has been criminative stimulus signals whether a response, if reinforced (or punished) in forcer that maintained the response is withheld or is no longer available. At first, there may be a spurt made, will pay off. In a Skinner box containing a pi- the presence of one stim- of responding, but then the responses gradually geon, a light may serve as a discriminative stimulus ulus to occur (or be sup- pressed) in the presence taper off and eventually cease. Suppose you put a for pecking at a circle. When the light is on, peck- of other similar stimuli. coin in a vending machine and get nothing back. ing brings a reward; when it is off, pecking is futile. You may throw in another coin, or perhaps even Human behavior is controlled by many discrimina- stimulus discrimina- two, but then you will probably stop trying. The tive stimuli, both verbal (“Store hours are 9 to 5”) tion In operant condition- next day, you may put in yet another coin, an exam- and nonverbal (traffic lights, doorbells, the ring of ing, the tendency of a ple of spontaneous recovery. Eventually, however, you your cell phone, other people’s facial expressions). response to occur in the will give up on that machine. Your response will Learning to respond correctly when such stimuli presence of one stimulus are present allows us to get through the day effi- have been extinguished. but not in the presence of ciently and to get along with others. other, similar stimuli that differ from it on some Stimulus Generalization and Discrimina- dimension. tion In operant conditioning, as in classical, Learning on Schedule When a response is stimulus generalization may occur. That is, re- first acquired, learning is usually most rapid if the discriminative stimu- sponses may generalize to stimuli that were not response is reinforced each time it occurs; this pro- lus A stimulus that sig- present during the original learning situation but cedure is called continuous reinforcement. How- nals when a particular resemble the original stimuli in some way; a pigeon ever, once a response has become reliable, it will be response is likely to be that has been trained to peck at a picture of a circle more resistant to extinction if it is rewarded on an followed by a certain type may also peck at a slightly oval figure. But if you intermittent (partial) schedule of reinforcement, of consequence. wanted to train the bird to discriminate between which involves reinforcing only some responses, continuous reinforce- the two shapes, you would present both the circle not all of them. Skinner (1956) happened on this ment A reinforcement and the oval, giving reinforcers whenever the bird fact when he ran short of food pellets for his rats schedule in which a par- pecked at the circle and withholding reinforcers and was forced to deliver reinforcers less often. ticular response is always when it pecked at the oval. Eventually, stimulus dis- (Not all scientific discoveries are planned!) On in- reinforced. crimination would occur. Pigeons, in fact, have termittent schedules, a reinforcer is delivered only  CHAPTER 9 Learning and Conditioning 313 after a certain number of responses occur or after a certain amount of time has passed since a response was last reinforced; these patterns affect the rate, © 2001 Charles Barsotti from cartoonbank.com. form, and timing of behavior. (The details are be- yond the scope of this book.) Intermittent reinforcement helps explain why people often get attached to “lucky” hats, charms, and rituals. A batter pulls his earlobe, gets a home run, and from then on All rights reserved. always pulls his earlobe Thinking Critically about Superstitions before each pitch. A stu- dent takes an exam with a purple pen and gets an A, and from then on will not take an exam without a purple pen. Such rituals persist because some- times they are followed purely coincidentally by a work so hard for an unpredictable, infrequent bit of intermittent (partial) reinforcer—a home run, a good grade—and so they food that the energy they expend is greater than schedule of reinforce- become resistant to extinction. that gained from the reward; theoretically, they ment A reinforcement Skinner (1948/1976) once demonstrated this could actually work themselves to death. schedule in which a phenomenon by creating eight “superstitious” pi- It follows that if you want to get rid of a re- particular response is geons in his laboratory. He rigged the pigeons’ cages sometimes but not always sponse, whether it’s your own or someone else’s, you so that food was delivered every 15 seconds, even if reinforced. should be careful not to reinforce it intermittently. If the birds didn’t lift a feather. Pigeons are often in you are going to extinguish undesirable behavior by shaping An operant- motion, so when the food came, each animal was ignoring it—a child’s tantrums, a friend’s midnight conditioning procedure in likely to be doing something. That something was phone calls, a parent’s unwanted advice—you must which successive approxi- then reinforced by delivery of the food. The behav- be absolutely consistent in withholding reinforce- mations of a desired ior, of course, was reinforced entirely by chance, but ment (your attention). Otherwise, the other person response are reinforced. it still became more likely to occur and thus to be re- will learn that if he or she keeps up the screaming, inforced again. Within a short time, six of the pi- calling, or advice giving long enough, it will eventu- successive approxima- geons were practicing some sort of consistent ritual: ally be rewarded. One of the most common errors tions In the operant- turning in counterclockwise circles, bobbing their people make is to reward intermittently the very re- conditioning procedure of heads up and down, or swinging their heads to and shaping, behaviors that sponses that they would like to eliminate. fro. None of these activities had the least effect on are ordered in terms of the delivery of the reinforcer; the birds were behav- Shaping For a response to be reinforced, it must increasing similarity or closeness to the desired ing “superstitiously,” as if they thought their move- first occur. But suppose you want to train Harry the response. ments were responsible for bringing the food. hamster to pick up a marble, a child to use a knife Now listen up, because here comes one of the and fork properly, or a friend to play terrific tennis. most useful things to know about operant condi- Such behaviors, and most others in everyday life, tioning: If you want a response to persist after it has have almost no probability of appearing sponta- been learned, you should reinforce it intermittently, neously. You could grow old and gray waiting for not continuously. If you are giving Harry, your them to occur so that you could reinforce them. hamster, a treat every time he pushes a ball with his The operant solution is a procedure called shaping. Simulate nose, and then you suddenly stop the reinforce- In shaping, you start by reinforcing a tendency Shaping on ment, Harry will soon stop pushing that ball. Be- in the right direction, and then you gradually re- mypsychlab.com cause the change in reinforcement is large, from quire responses that are more and more similar to continuous to none at all, Harry will easily discern the final desired response. The responses that you the change. But if you have been reinforcing reinforce on the way to the final one are called Harry’s behavior only every so often, the change successive approximations. In the case of Harry and will not be so dramatic, and your hungry hamster the marble, you might deliver a food pellet if the will keep responding for quite a while. Pigeons, hamster merely turned toward the marble. Once rats, and people on intermittent schedules of rein- this response was established, you might then re- forcement have responded in the laboratory thou- ward the hamster for taking a step toward the mar- sands of times without reinforcement before ble. After that, you could reward him for throwing in the towel, especially when the timing approaching the marble, then for touching the of the reinforcer varies. Animals will sometimes marble, then for putting both paws on the marble, 314 CHAPTER 9 Learning and Conditioning Behavioral techniques such as shaping have and finally for holding it. With the achievement of Years ago, two psychologists who became ani- many useful applications. Monkeys have been each approximation, the next one would become mal trainers, Keller and Marian Breland (1961), trained to assist their more likely, making it available for reinforcement. learned what happens when you ignore biological paralyzed owners by Using shaping and other techniques, Skinner constraints on learning. They found that their ani- opening doors, helping was able to train pigeons to play Ping-Pong with mals were having trouble learning tasks that should with feeding, and turning their beaks and to “bowl” in a miniature alley, com- have been easy. One animal, a pig, was supposed to the pages of books. plete with a wooden ball and tiny bowling pins. drop large wooden coins in a box. Instead, the ani- Miniature guide horses (Skinner had a great sense of humor.) Animal train- mal would drop the coin, push at it with its snout, help blind people navigate city streets and subways. ers routinely use shaping to teach animals to act as throw it in the air, and push at it some more. This Note the horse’s cool the “eyes” of the blind and to act as the “limbs” of odd behavior actua