B.F. Skinner and Operant Conditioning B.F. Skinner had an enormous influence on psychology in general and on the field of psychology known as behaviorism in particular. His key theories were published in the early 1950s. As Pavlov’s experiments showed, classical conditioning involves associating a neutral external stimulus with a response that is generally automatic (such as salivating). Skinner’s research revealed the power of operant conditioning, which involves learning how to operate on one’s environment to elicit a particular stimulus (a reward) or to avoid a punishment. In operant conditioning, the subject controls his or her response. You will learn how this works in the next few slides. Classical conditioning involves an automatic response to a stimulus Operant conditioning involves learning how to control one’s response to elicit a reward or avoid a punishment

The “Skinner Box”: Skinner’s Hypothesis, Methodology, and Results Rats placed in “Skinner boxes” Shaped to get closer and closer to the bar in order to receive food Eventually required to press the bar to receive food Food is a reinforcer Skinner hypothesized that rats could be trained to perform specific behaviors in order to receive a food reward. He placed the rats into what is technically called an “operant chamber” but became more commonly known as a “Skinner box.” The soundproof glass box contained a bar or a key that the rat could press down to receive food. This bar or key was hooked up to an instrument that recorded how many times the rat pressed it. Skinner used a process called “shaping” to teach the rats to press the bar for food. For example, if a rat approached the bar, he might initially give it a pellet of food as a reward for getting close to the bar. Skinner would gradually make the rat get closer to the bar before giving it food. Eventually, the rat learned that it had to press the bar in order to get any food. The food in this case is referred to as a “reinforcer,” since it reinforces the rat’s behavior of stepping closer to and eventually pressing the bar.

Basic Types of Reinforcement Reinforcer: any event that increases or strengthens a behavior it follows. Primary Reinforcer: innately satisfying (not learned, i.e. food) Secondary (conditioned) Reinforcer: power through association with primary reinforcers (learned, i.e. good grades) Skinner and his associates tried the following types of reinforcement schedules with animals such as rats and pigeons: Fixed-ratio: In a fixed-ratio schedule, behavior is reinforced after a set number of responses. For example, an animal might receive food every ten times it presses the bar. After receiving its food reward, the rat presses the bar rapidly until it receives another one. Variable-ratio: Reinforcement is provided after a variable number of responses. Sometimes the animal receives food after two responses, sometimes after twenty; the number of times the rat has to press the bar varies. Animals press the bar frequently because they know they’ll get more food the more they press. Fixed-interval: Reinforcement is based on a time schedule. As the time for another reward draws near, the animal will press the bar more often. Variable-interval: Reinforcement is provided from time to time at a variable rate but is not dependent on how many times the rat presses the bar. The animal tends to press the bar at a slow but steady rate since it has no idea how long it will have to wait for its reward. Can you think of examples of these types of reinforcement in people’s lives? What about gambling? What about factory work in which people are paid by the number of items they produce? What about jobs that pay hourly wages? Positive Reinforcement: strengthens a response by presenting a stimulus after a response (Praise, money) Pass Out Handout!

Negative Reinforcement and Punishment Negative reinforcement: Removing an unpleasant stimulus Punishment 1. Introducing an unpleasant stimulus 1. Unpleasant stimulus = In operant conditioning, negative reinforcement and punishment are two different things that can be easy to confuse. The food rewards Skinner used are known as positive reinforcement. Negative reinforcement, on the other hand, occurs when an unpleasant stimulus is removed. For example, in one experiment Skinner would play a loud noise inside the box; to make the noise stop, the rat would have to press the bar. Punishment involves either the introduction of an unpleasant stimulus or the removal of a pleasant stimulus. When Skinner gave a rat a painful electric shock after pushing the bar, the rat learned not to push the bar. Another example of punishment would be a parent withholding dessert from a child who misbehaves at the dinner table. 2. Removal of unpleasant stimulus 2. Withholding a pleasant stimulus =

Law of Effect-Thorndike Reinforced behaviors are strengthened Punished behaviors are decreased

Rates and Types of Reinforcement: Additional Experiments Fixed-ratio: after a fixed number of responses reinforcement is given. (sales) Produces high response rate Variable-ratio: after an unpredictable number of responses reinforcement is given (gambling) Produces high response rate Skinner and his associates tried the following types of reinforcement schedules with animals such as rats and pigeons: Fixed-ratio: In a fixed-ratio schedule, behavior is reinforced after a set number of responses. For example, an animal might receive food every ten times it presses the bar. After receiving its food reward, the rat presses the bar rapidly until it receives another one. Variable-ratio: Reinforcement is provided after a variable number of responses. Sometimes the animal receives food after two responses, sometimes after twenty; the number of times the rat has to press the bar varies. Animals press the bar frequently because they know they’ll get more food the more they press. Fixed-interval: Reinforcement is based on a time schedule. As the time for another reward draws near, the animal will press the bar more often. Variable-interval: Reinforcement is provided from time to time at a variable rate but is not dependent on how many times the rat presses the bar. The animal tends to press the bar at a slow but steady rate since it has no idea how long it will have to wait for its reward. Can you think of examples of these types of reinforcement in people’s lives? What about gambling? What about factory work in which people are paid by the number of items they produce? What about jobs that pay hourly wages? Fixed-interval: after a fixed amount of time reinforcement is given. (mail) Variable-interval: after an unpredictable amount of time reinforcement is given (email) Predictability Matters

Skinner’s Importance Education: programmed instruction Work Parenting Personal goals Skinner believed that humans learn behavior through reinforcement, much as rats learn to press a bar when that behavior is reinforced with food. His contributions to the fields of psychology and education therefore focused on learned behaviors and reinforcement. For example, Skinner and his followers promoted the use of machines to teach students concepts in small incremental steps, giving them rewards for right answers; this method is called “programmed instruction.” Skinner emphasized the importance of receiving feedback for each step (e.g., for each math problem in a sequence) before going on to the next one. Skinner’s behaviorist ideas have also been used in the workplace to give workers added incentives and to provide immediate reinforcement for good work. Operant conditioning also appears commonly as a parenting technique, as when parents reinforce good behaviors and try to extinguish negative behaviors. It’s also possible to use Skinner’s techniques to accomplish personal goals. Imagine that you want to spend more time on your psychology homework but never seem to get around to it or feel that you can’t get organized. You could begin by observing how much studying you currently do for this class. You’d then set a goal to study a certain number of minutes or hours more each evening and to reinforce that behavior with a reward (such as candy or time playing a video game). Over time, your study skills would hopefully become more natural and you wouldn’t always need the reward.

Albert Bandura: Hypothesis = The experiments of Pavlov and Skinner clearly proved that humans can be conditioned to have certain responses and behaviors. This conditioning represents just one type of learning. Albert Bandura believed that we also learn from observing and imitating others and that, in fact, learning can be much easier when done in this social context. He then hypothesized that children could learn aggressive behavior by observing adults behaving aggressively. His key theories were published in the early 1960s. Believed we learn through observation and imitation Hypothesized that children would imitate aggressive behavior they observed

Bandura’s Methodology Bandura had preschool children watch films in which adults punched inflatable dolls, called Bobo dolls, while yelling such things as, “Pow—right in the nose!” The children were divided into three groups. Each group saw the same film but with a different ending. The three endings could be categorized as follows: aggression-rewarded: the adult was praised and received treats at the end of the film; he was rewarded for his aggressive behavior toward the Bobo doll aggression-punished: the adult was punished by being called a bully, swatted, and made to cower no consequences: the adult was neither rewarded nor punished for his aggressive behavior toward the Bobo doll Children watched films of adults beating Bobo dolls Three groups: aggression-rewarded, aggression-punished, no consequences Children went into rooms with toys that they were told not to play with

EFFECT OF OBSERVED CONSEQUENCE ON IMITATIVE BEHAVIOR Bandura’s Results EFFECT OF OBSERVED CONSEQUENCE ON IMITATIVE BEHAVIOR Immediately after watching this film, the children in all groups were taken into a room with toys but told not to play with the toys. They were then taken into another room with a Bobo doll and other toys, much as they’d seen in the film. By this time, children were generally frustrated that they hadn’t been able to play with any of the toys. Researchers observed their behavior and found that the children who had watched the aggression-rewarded and the no consequences films were equally likely to behave aggressively toward the Bobo doll. Children who had watched the aggression-punished film, however, imitated the adults in their aggression significantly fewer times than children in the other two groups. Children in the aggression-punished group expressed the fewest aggressive behaviors toward the Bobo dolls Children in the other two groups expressed an equal number of aggressive behaviors and were more aggressive than children in the aggression-punished group

Bandura’s Experiment, continued + = Viewing aggressive behavior Rewards for imitation Aggressive behavior The experiment continued when an adult researcher told the children that they’d be rewarded with stickers and juice if they could imitate the adult they had seen in the film. After this promise, the children in all three groups exhibited an equal number of aggressive behaviors toward the Bobo dolls. They had apparently learned the aggressive adult’s behaviors but, in the case of the aggression-punished group, had suppressed imitation for fear of punishment. Children promised rewards for imitating the adult in the film Now, all three groups were equally aggressive Children had learned the aggressive behavior from the film, but those who saw the adults being punished were less likely to act aggressively

Bandura’s Social Learning Theory Bandura’s results led him to develop his social learning theory, which states that we learn by observation and imitation. Bandura’s theory has numerous implications. For example, subsequent research has indicated that children imitate the things they see on television and in movies, including acts of aggression and violence. Research indicates that children who have watched a violent TV program or movie might not imitate the actual behavior they observed, such as killing or beating, but they may be more likely to express generally aggressive behaviors such as hitting a sibling. On the other hand, children imitate good or neutral behavior as well, such as performing nice deeds for other people or assembling a puzzle. Think about the ways in which you, either now or at a younger age, have learned through observation and imitation. Relates to effects of violence and other images on TV and in the movies Children imitate good and neutral behaviors as well as bad ones