B.F. Skinner
Burrhus Frederic Skinner was born
March 20th 1904. His
upbringing in the small Pennsylvania town of Susquehanna was old-fashioned and hard
working. He enjoyed school, but
didn’t fit in very well.
While pursuing his BA in English from Hamilton College, he wrote for the
school paper, including articles that were critical of the school, the faculty
and even Phi Beta Kappa. Skinner
got his masters and his doctorate degrees in 1930 and 1931, respectively: both
from Harvard. In 1936, Skinner
moved to Minneapolis to teach at the University of Minnesota. This is where he met his wife, Yvonne
Blue. The Skinners had two daughters, the youngest of which became known for
being raised in Skinner’s “air crib.” In 1948, Skinner was invited to come to
Harvard, and he stayed there the rest of his life. Sadly, Skinner died of leukemia on August 18th
1990. He is considered by many to
be the most celebrated psychologist since Freud. (Nye, 1-13)
B.F. Skinner’s entire system
is based on operant conditioning.
This is based on the idea that learning is a function of change in overt
behavior. Changes in behavior are
the result of an individual’s response to events (stimuli) that occur in
the environment. A response
produces a consequence such as defining a word, hitting a ball, or solving a
math problem. When a particular
Stimulus-Response (S-R) pattern is reinforced, the individual is conditioned to
respond. The distinctive
characteristic of operant conditioning relative to previous forms of
behaviorism like E.L. Thorndike’s trial and error learning is that the
organism can emit responses instead of only eliciting response due to an
external stimulus. The core
concepts of operant conditioning are as follows:
Negative Reinforcement:
Behavior followed by the removal of an aversive stimulus results in an
increased probability of that behavior occurring in the future.
Positive Reinforcement: A
behavior followed by a reinforcing stimulus results in an increased probability
of that behavior occurring in the future.
Punishment: A
behavior followed by an aversive stimulus results in a decreased probability of
the behavior occurring in the future.
Extinction: A
behavior no longer followed by the reinforcing stimulus results in a decreased
probability of that behavior occurring in the future.
An aversive stimulus is the
opposite of a reinforcing stimulus; it is something unpleasant or painful. Using the above-mentioned concepts,
Skinner was able to teach animals completely new behaviors that would have
never shown up in their natural environment. He did this by shaping. Shaping is the method of
successive approximations. It
involves first reinforcing a behavior that may barely resemble the desired
behavior. Once that is
established, you watch for variations of that behavior that more closely
resemble the desired behavior, and reinforce them. This continues until the desired behavior is achieved. (Domjan, 128-130)
Skinner was said to enjoy telling
the story about how he “accidentally” discovered schedules of
reinforcement. He was running low
on food pellets in the middle of a study.
Skinner had to make these pellets himself, and it was a very tedious
task. So, he decided to reduce the
number of reinforcements he gave his rats for whatever behavior he was trying
to condition. Despite this, his
rats kept up their operant behaviors at a stable rate.
Skinner eventually developed five
total schedules of reinforcement, they are:
Continuous Reinforcement: Every
time the rat does the appropriate behavior, he gets a pellet.
Fixed ratio schedule: If
the rat presses the pedal three times, he gets a pellet…or five times, or
twenty times, or x times. There is
a fixed ratio between behaviors and reinforcers.
Fixed interval schedule: If
the rat presses the bar at least once during a particular period of time, say
20 seconds, he gets a pellet. But
whether he presses the bar once or a hundred times within that 20 seconds, he
only receives one reinforcer.
Variable ratio schedule: You
change the x each time. First it
takes 3 presses to get a pellet, then 10, then 4, etc.
Variable interval schedule: You
keep changing the time period.
First 10 seconds, then 35, then 5, then 40.
Using these schedules of
reinforcement, Skinner was able to condition behaviors that were very resistant
to extinction. An interesting fact
about Skinner was that he did not approve of the use of aversive stimuli. This opinion was not due to ethics, he
simply said they didn’t work as well. (Corsini, 382-404)
Throughout his life, Skinner became
known for many of his works. One
of the firsts was the “Baby Tender.” In 1943, Skinner’s wife was pregnant with their second
child. His wife wondered if
Skinner could design a crib that would be safer than the typical crib with bars
that could trap a leg and blankets that could suffocate a baby. This is when he created the baby
tender. It was an enclosed, heated
crib with a plexiglass window.
This crib was only used as a bed for the new baby, but confusion
occurred between the baby tender and the “Skinner Box.” To this day Skinner’s name is
plagued by rumors about his daughter being raised in a box. (Nye, 36-43) Another project of Skinner’s that
became well known is Project Pigeon.
In 1944, World War II was in full swing. Airplanes and bombs were common, but there were no missile
guidance systems. Skinner sought
funding for a top-secret project to train pigeons to guide bombs. He successfully trained the pigeons to
continuously peck a target that would hold a missile onto a target, but his
project was discontinued when another top-secret project, radar, was
started. (Corsini, 387)
One of Skinner’s works that
is widely used in the academic setting is his book Walden Two. In
this book, a professor and several other individuals go to visit a community
called Walden Two, a group of about one thousand members. The community’s designer,
Frazier, explains how the happy and industrious behaviors they are seeing have been
carefully shaped using behavioral engineering. All aspects of the community have been planned. (Skinner, 1-200) This book is actually based on
Skinner’s own principles and to this day is still highly praised and
condemned. Some people, especially
religious organizations come down hard on this book. They said that his ideas take away from our freedom and
dignity as human beings. He
responded to this criticism with another book called, Beyond Freedom
and Dignity. In this book he asked:
“What do we
mean when we say we want to be free?
Usually we mean we don’t want to be in a society that punishes us
for doing what we want to do.
Okay, aversive stimuli don’t work well anyway, so out with
them: Instead, we’ll only
use reinforcers to “control” society. And if we pick the right reinforcers, we will feel free,
because we will be doing what we feel we want! Likewise for dignity.
When we say “she died with dignity,” what do we mean? We mean she kept up her
“good” behaviors without any apparent ulterior motives. In fact, she kept her dignity because
her reinforcement history has led her to see behaving in that
“dignified” manner as more reinforcing than making a scene. The bad do bad because the bad is
rewarded. The good do good because
the good is rewarded. There is no
true freedom or dignity. Right
now, our reinforcers for good and bad behavior are chaotic and out of our
control, it’s a matter of having good or bad luck with your
“choice” of parents, teachers, peers, and other influences. Let’s instead take control, as a
society, and design our culture in such a way that good gets rewarded and bad
gets extinguished! With the right
behavioral technology, we can design culture.” (Skinner, 14)
Skinner’s work is the
cornerstone for many theories and practices. One of which is Behavior Modification. This is the therapy technique that
extinguishes an undesirable behavior by removing the reinforcer, and replacing
it with a desirable behavior by reinforcement. It has been used on many types of psychological problems
including addictions, neuroses, autism and schizophrenia. Another practice that came from
behavior modification is the token economy. The token economy is a system of
behavior modification that employs tokens, often poker chips, as reinforcers. The tokens are awarded for good
behaviors, and taken away for bad behaviors. These tokens can be exchanged for things like cigarettes,
movies, games, etc. The token
economy system has been found to be very effective in maintaining order in prisons,
mental institutions, and juvenile delinquent homes. (Domjan, 303-305)
Tolman
Edward Tolman, using a different
perspective, came to a conclusion similar to Skinner’s. He is credited with having been the
first to have clearly formulated the concept of the intervening variable within the behavioral tradition. That is, something is going on inside
the organism that mediates the link between what is perceived and what behavior
is performed. He earned his Ph. D.
from Harvard in 1915, and spent most of his career at the University of
California, Berkeley. His approach
to human behavior involved a synthesis of Gestalt psychology and behaviorism,
focusing on an entire, goal-directed action, including both muscular responses
and the cognitive processes that direct them. Tolman’s theorizing has been called purposive
behaviorism and is often considered to be the bridge between behaviorism and
cognitive theory. According to his
theory of sign learning, on organism learns by pursuing signs to a goal. In other words, learning is acquired
through meaningful behavior.
Tolman emphasized the organized aspect of learning: “The stimuli which are allowed in
are not connected by just simple one-to-one switches to the outgoing
responses. Rather the incoming
impulses are usually worked over and elaborated in the central control room
into a tentative cognitive-like map of the environment. And it is this tentative map,
indicating routes and paths and environmental relationships, which finally
determines what responses the animal will finally make.” (Domjan,
168-170)
Tolman was also the first to
selectively breed rats for high and low maze-solving abilities. Tolman’s ideas provided another
springboard to cognitive psychology, because Tolman argued that rats build up a
mental representation or cognitive map
of the environment they are in. In
theory, a rat can respond to a stimulus not by a direct motor response, but by
referring the stimulus to its cognitive model, thereby assessing its
significance by some mental process, and only then doing something about
it. Corsini, 213)
Tolman characterized his views as
molar behaviorism, as opposed to what he termed Watson’s molecular
position. In Watson’s view,
behavior could be defined as muscular responses caused by the stimuli with
which they had become associated:
in Tolman’s view, a response category was associated with a
stimulus. For example, if a person
learned to pull back their finger from an electrode with a warning signal that
preceded an electric shock, the molecularist would say that a specific
conditioned reflex has been learned.
By contrast, a molar behaviorist would claim that a global avoidance
response had been learned. Tolman
saw an organism as a complex machine, capable of various adjustments so that,
when one adjustment was in force, a given stimulus would produce one response,
while under a different internal adjustment, it would call out a different
response. These adjustments could
be caused by external stimuli or by changes within the organism. Domjan, 170)
Tolman proposed five types of
learning:
Tolman claimed that all forms of
learning depend on means-end readiness, or goal-oriented behavior. This behavior is mediated by
expectations, perceptions, representations, and other variables. His version of behaviorism emphasized
the relationships between stimuli rather than S-R. The main principles of Tolman’s Theory are:
Both Tolman and Skinner hugely
contributed to learning theory and are both celebrated researchers. Their contributions to psychology are
highly important in understanding behavioral outcomes, which is one of the main
reasons psychology exists in the first place…to predict and understand
behavior! (Corsini, 215)
Works Cited
Corsini
Encyclopedia of Psychology and Behavioral Science. John Wiley and Sons
Publication
Co. Copyright 2002.
Domjan, M. The Principles of Learning and
Behavior. 5th edition. Wadsworth
Publishing
Copyright 2003.
Nye, R.D. The
Legacy of B.F. Skinner. Brooks/Cole Publishing Company. Copyright
1992
Skinner, B. F. Walden
Two.
Prentice Hall reissue edition.
Copyright 1976.
Skinner, B.F. Beyond
Freedom and Dignity. Hackett Publishing Company. Copyright
March 2002.