- Albert Bandura
Major Behavioral Psychology Theories and theorists of Learning.
I. Classical conditioning theory
- Ivan Pavlov, John B. Watson
II. Operant or Instrumental conditioning
- E.L. Thorndike, B.F. Skinner
III. Social learning theory - observational learning & modeling
- Albert Bandura
Behavioral Psychology -
or behaviorism, is a major theoretical field in psychology. Behaviorism is a philosophy that assumes:
- The proper concern of psychological science should be the study of observable behavior and responses. Concepts such as "consciousness" or even "the mind" cannot be meaningfully defined and therefore, should not be studied by scientists.
- People are born as "blank slates". This assumption is based on the philosophy of John Locke (1690) who described the mind as a tabula rasa. Whatever people learn to do (this means all behavior), depends on their interactions and experiences with the environment.
- Changes in behavior (i.e. learning) follow the Law of Effect. E.L. Thorndike defined this law which says: "behavior that is followed by satisfying consequences will be more likely to be repeated and behavior that is followed by unsatisfying consequences will be less likely to be repeated".
- Changes in behavior or learning can occur automatically as people (and all organisms) discover Contingency Relationships - the occurrence of one event is dependent on or determined by the occurrence of another event. This is also called associative learning.
I. Classical Conditioning Theory - Classical conditioning is based on the work of Ivan Pavlov and John B. Watson.
Pavlov - was an Russian physiologist doing research at the St. Petersburg University School of Medicine. He was awarded a Nobel Prize for science, for his research on digestion and ulcers. Believe it or not, this is what led Pavlov to study learning in dogs.......which led to the basic components of classical conditioning theory:
a) There are stimulus --> response relationships that occur in nature. Pavlov called these naturally occurring events unconditioned stimuli (UCS) and unconditioned responses (UCR). Here are some examples:
Unconditioned Stimuli ---> Unconditioned Responses 1. meat for dinner the dog salivates 2. a balloon pop a startle response 3. an air puff to your eye blinking your eye b) When a neutral stimulus and unconditioned stimulus are presented together often enough, they becomes associated - thus the neutral stimulus is like a signal or clue that the unconditioned stimulus is coming next. After several pairings, the neutral stimulus becomes a conditioned stimulus (CS) because it elicits behavior that is a mild form of the UCR - this mild behavior is called the conditioned response (CR).
c) Important terms
acquisition - the initial phase of classical conditioning where an organism is learning to associate a neutral stimulus with an unconditional stimulus
extinction - a phase in classical conditioning where an organism learns that a previously conditioned stimulus no longer is associated with an unconditional stimulus
spontaneous recovery - the reappearance of a conditioned behavior following an extinction phase
response generalization - the tendency to respond to stimuli that are similar to a previously conditioned stimulus (CR)
stimulus discrimination - the tendency to distinguish between similar stimuli, responding to one but not the other
John B. Watson - was one of the first people to earn a Ph.D. in psychology in the United States in 1902. Only a few universities had a psychology department in 1902 and even fewer has animal research laboratories. So, in graduate school Watson collected city rats and set up experiments in his apartment; later he set up research labs at Johns Hopkins University. Watson also conducted his experiments with Little Albert, a one-year old boy, and other children to show how classical conditioning can create phobias and other mental health problems.
Little Albert's mother stopped Watson's experiment with her son once she found out the details of the study and complained to the University. Watson was warned about his questionable lab procedures and later was fired for studying human sexual responses with this lab assistant, Rosalie Rayner. No one knows what happened to Little Albert.
II. Operant Conditioning Theory - based on the work of E.L. Thorndike and B.F. Skinner.
E. L. Thorndike – was studying mind reading in children for his Ph.D. dissertation. He asked children to guess what he was thinking and if they guessed right, he rewarded them with a piece of candy. What he observed was that children made the same guesses again when it led to a piece of candy. Well, the research with children was a failure – so he switched to studying learning with animals. And this led to the Law of Effect (1898). The simple version is:
Learning = behavior + consequences
Thorndike built a puzzle box for cats. The cat was placed inside; it thrashed about randomly until it happened to press a latch that opened a door so the cat could escape. This is an acquisition trial. Thorndike put the cat back in the box repeatedly. Eventually, the cat learned exactly what to do –press the latch to escape from the box. Pressing the latch was the behavior that led to a satisfying event – the escape.
B.F. Skinner – started with Thorndike’s theory and made some important changes:
1. He changed the learning environment. In Thorndike’s box, the cat only had an opportunity to learn when the experimenter put it in the learning environment. In other words, the experimenter controlled the cat's opportunities for learning. Skinner created an operant conditioning chamber (everyone else called this kind of apparatus a Skinner Box). The animal could remain in the chamber and have unlimited opportunities to learn. An example was a rat cage with food, water, an exercise wheel, etc., but it also contained a lever that the rat could press to get more food. The rat is free to press the lever repeatedly. (How should this change in environment affect the rate of learning?)
2. Skinner's boxes (operant conditioning apparatuses) helped him discover shaping. Obviously, the rat doesn’t know that pressing the lever will get more food – so it has to be rewarded for successively closer approximations of the desired response. In other words, the experimenter gives a food pellet to the rat only if it is close to the lever, then only if it stands on its’ hind legs next to the lever, then only if it touches the lever......until the rat presses the lever by itself.
(Do you think shaping could lead to strange behavior? What is an example? Why would this happen?)
3. Skinner also discovered schedules of reinforcement. Rather than giving a reinforcement (i.e. a food pellet) after every response (i.e. a lever press), Skinner fixed the operant conditioning chamber to give a reinforcement only after 2 or 3 responses. This is a partial reinforcement schedule. Learning with a partial reinforcement schedule is more resistant to extinction.
(Why do you think this is?)
4. Ratio & Interval reinforcement schedules. Ratio schedules give reinforcement after x number of responses. The ratio of responses to reinforcement can be either fixed or variable. A fixed ratio schedule gives reinforcement after every (5) responses, for example. A variable ratio schedule gives reinforcement ‘on the average’ every (5) trials – sometimes the reinforcement comes after 2 responses, then after 7 responses, then 6 responses, etc. , so that reinforcement occurs on the average after every 5 responses.
Interval schedules give reinforcement after a time interval. A fixed interval schedule gives reinforcement every (5) minutes. A variable interval schedule gives reinforcement ‘on the average’ every five minutes - sometimes the reinforcement comes after 2 minutes, then after 7 minutes, then 6 minutes, etc.
(Which type of reinforcement should lead to faster responding –ratio or interval schedules? Why?) (Can you think of examples of ratio or interval schedules that occur in daily life?)
5. Types of reinforcement are positive reinforcement, negative reinforcement, and punishment.
- Positive reinforcement - the organism performs the desired behavior and gets a desirable reward. For example, a rat presses a level and is rewarded with a food pellet.
- Negative reinforcement - an undesirable event occurs until the organism performs the desired behavior. For example, the floor of the rat cage is electrified until the rat presses a lever to turn off the electricity. Positive and negative reinforcement both increase the frequency of behavior.
- Punishment - is the opposite of reinforcement. It decreases the frequency of the behavior. The organism performs an undesirable behavior and an aversive or negative consequence is administered.
(Can you think of examples of positive reinforcement in everyday life? Can you think of examples of negative reinforcement? Can you think of examples of punishment?)
6. Secondary reinforcement – some reinforcers are only signals that a positive reinforcement is on the way. For example, Skinner fixed an operant conditioning chamber to give food pellets when the rat pressed a lever but only if a signal light was on. When the light was off, the rat could not get food by pressing the lever. Next, Skinner trained the rat to do something else to turn on the light. For example, running in the exercise wheel will turn on the light.....so the rat learned to run in the wheel, then press the lever whenever it wanted to eat.
(Can you think of secondary reinforcers in everyday life - things you work for in order to get something else that you find desirable?)* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
B.F. Skinner (died in 1990 of Leukemia) - research and writing has had a huge impact on American Psychology and American society in general. His work has influenced how information is organized and presented in textbooks for elementary school through college, as well as how many computer tutorial programs are written. Also, many employee incentive & motivational programs use reinforcement principles as defined by Skinner. For more information on the life & work of Skinner, you can visit the B.F. Skinner Foundation http://www.bfskinner.org/
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What are some differences between classical and operant conditioning?
Classical Conditioning Operant Conditioning Response Involuntary, automatic Voluntary, operates on the environment Acquisition Associating events; CS announces UCS Associating response with a Consequence (reinforcer or punisher). Extinction CR decreases when CS is repeatedly presented alone.
Responding decreases when reinforcement stops. Biological Predisposition Natural predispositions contain what stimuli and responses can easily be associated. Organisms best learn behaviors similar to their natural behaviors; unnatural behaviors instinctively drift back toward natural ones.
Are there any problems with pure behaviorism?
What is your opinion of behavioral psychology, especially classical and operant conditioning?
Are the things that you like or that make sense to you? Why?
Are there things that you dislike or do not make sense? Why?
Do the principles of behavioral psychology explain everything about human behavior?
What are examples of human behavior that behavioral psychology does not seem to explain?
III. Social Learning Theory
Pure Behaviorism, according to theorists like Skinner and Watson, can explain any behavior without using abstract concepts like memory, thinking, or consciousness. Only S-->R contingencies are necessary to explain behavior. Complex behaviors are combinations of simpler behaviors. Simple behaviors are conditioned then combined through shaping, secondary reinforcement, and various other reinforcement schedules.
- People do think; cognitive processes are important parts of learning.
- Pure behaviorists assume that performance is necessary for learning to occur. But we can learn by watching others, through observational learning and latent learning processes. (Tolman’s anesthetized rats in the trolley cars)
- Over justification effect & intrinsic motivation - There are some behaviors that people perform .... "just because"..... and not because they expect to earn a reward or avoid a punishment. (Deci's experiment paying children to draw pictures)
Albert Bandura proposed social learning theory. Because people do think, observe and remember things, they can learn through modeling and imitation. Performing behaviors in acquisition trials used in classical and operant conditioning are not necessary for learning. (Bandura's bobo doll study)
