B.F Skinner (Burrhus Frederic Skinner): Reinforcement Theory and Operant Conditioning I. What Differentiates Skinner from the Other Theorists? He bases his investigations on facts and observations o Skinner tells us that “psychology is the science of what an organism does”. o He focuses on behavior, and not just on personality o He also believed that Investigations should be based on facts—which can be seen, manipulated, and measured in the laboratory o He differs not only in subject (behavior), but also in methodology and aims (his use of animals as samples). Use of Rats and Pigeons o He uses animals for his investigations because he believes that studies should develop from simple to complex. o Because of that, since human beings are complex organisms, it will be more difficult to observe and analyze them— so he used animals to be his samples. o First, it was because animals don’t differ greatly from humans. o Second, animals also respond to stimuli, sometimes even greater than the humans. o Lastly, it is because animal and human behavior doesn’t vary in degrees- only in kind. Humans are empty organisms o For Skinner, we are empty organisms– there is nothing inside us that can explain behavior in scientific terms. o Unlike other theorists such as Jung or Freud, he made no reference to internal, subjective states to define behavior. o He says that these unconscious influences, defense mechanisms, etc. cannot be seen– thus, they are not fit for scientific psychology. o But he did not deny the existence of these internal forces, only their usefulness for science.
II. The Life of BF Skinner He was born in Susquehanna, Pennsylvania, to Grace and William Skinner, and was the elder of two sons. His father was a lawyer. His brother Edward, two and a half years his junior, died at age sixteen of a cerebral hemorrhage. Even when Burrhus Frederic and his brother were youngsters, both of their parents imposed clear rules on proper behavior. Example would be when his mother would usually say “tut tut” when the kids are getting off the line. His grandmother would also always point to the hot coals in the parlor stove to make known the punishments of Hell. And his father teaches him about the fate that befell criminals. He even took the young Skinner to the county jail and to the New York state prison. It was clear that reinforcements, both negative and positive, shaped the way that Skinner has been brought up.
His interest on animal behavior was also derived during his childhood, when performing pigeons at a country fair fascinated him. His pets had comprised of turtles, toads, snakes, lizards, and even chipmunks. He attended Hamilton College in New York with the intention of becoming a writer. He wrote for the school paper, but as an atheist, he was critical of the religious school he attended. He also attended Harvard University after receiving his B.A. in English literature in 1926. After graduation, he spent a year at his parents' home in Scranton attempting to become a writer of fiction. He had wanted to be a novelist, after Robert Frost gave a favorable comment on his work. However, the inspiration to write halted for BF Skinner. At age 22, he was a failure at the only thing he wanted to do. He soon became disillusioned with his literary skills and concluded that he had little world experience and no strong personal perspective from which to write. Skinner received a PhD from Harvard in 1931, and remained there as a researcher until 1936. He then taught at the University of Minnesota at Minneapolis and later at Indiana University, where he was chair of the psychology department from 1946–1947, before returning to Harvard as a tenured professor in 1948. He remained at Harvard for the rest of his career. In 1936, Skinner married Yvonne Blue. The couple had two daughters, Julie and Deborah. He died of leukemia on August 18, 1990.
III. Ivan Pavlov Ivan Pavlov: Russian physiologist. His works were later adopted by John B. Watson as the basic method for behaviorism. …. He had observed that dogs tend to salivate to neutral stimuli such as the sound of the keeper’s footsteps, when before they only salivate at the sight of food. He was intrigued by his observation, and began to study the phenomenon more systematically. Ivan started to sound the bell shortly before feeding the dog. At first, the dog salivated only after seeing the food, and not to the bell, since it has no meaning. However, after a number of pairings of the bell followed by the food, the dog began to salivate at the sound of the bell. Thus, the dog has been conditioned/ trained to respond to the bell. • • •
Pavlov’s experiment demonstrated the importance of reinforcement. He then formulated a fundamental law of learning: – A conditioned response cannot be established in the absence of reinforcement. Reinforcing strengthens conditioning and increases the likelihood that the response will be repeated.
However, an established conditioned response will not be maintained in the absence of reinforcement. Take for example when the experimenter stops presenting food after sounding the bell. The dog hears the bell, but nothing happens– no food, no reinforcement, no reward. With successive ringing of the bell, the dog’s salivary response decreases in frequency and intensity until no response occurs at all. This process is called extinction.
IV. Theories of BF Skinner a. Reinforcement Theory Respondent Behavior: responses made to or elicited by specific environmental stimuli. Reinforcement: the act of strengthening a response by adding a reward, thus increasing the likelihood that the response will be repeated. Extinction: the process of eliminating a behavior by withholding reinforcement.
b. Schedules of Reinforcement Fixed interval: reinforcer is presented following the first response that occurs after a fixed time interval has elapsed. The interval might be 1 min, 3 min, or any other fixed period of time. The timing of reinforcers has nothing to do with the no. of responses. (eg: midterm and final examinations) Fixed Ratio: The reinforcer is presented following the 1st response that occurs after a fixed time interval has elapsed. Variable Interval: Reinforcers appear randomly. They might appear after 2 hours in the first instance, after 1 1/2 hours in the 2nd time, and after 2 hours and 15 minutes in the 3rd instance. Variable Ratio: Based on average number of responses between reinforcers, but there is great variability around the average.
c. Successive Approximation An explanation for the acquisition of complex behavior. An organism is reinforced as its behavior comes in successive or consecutive stages to approximate the final behavior desired. (eg: Learning to speak/ verbal behavior) d. Superstitious Behavior Persistent behavior that has a coincidental and not functional relationship to the reinforcement received. A single reinforcement is powerful enough to lead a person to repeat the accidentally reinforced behavior more frequently. The connection is unintentional. But these behaviors might persist throughout life and requires only occasional reinforcement to sustain them. e. Self-Control of Behavior: Self-control: the ability to exert control over variables that determine our behavior. It is acting to alter the impact of external events. He did not refer to the acting under the control of a â€œmysteriousâ€? self, but that we can control the external variables that determine our behavior, to some extent. Self-control techniques: i. STIMULUS AVOIDANCE: removing yourself from an external variable that affects your behavior. ii. SELF-ADMINISTERED SATIATION: we exert control to cure ourselves of bad habits by overdoing the behavior. iii. AVERSIVE STIMULATION TECHNIQUE: involves unpleasant or repugnant consequences. iv. SELF-REINFORCEMENT: we reward ourselves for displaying good or desired behaviors.