Sigmund (1856-1939), Austrian physician,
neurologist, and founder of psychoanalysis
In the late 19th century Viennese neurologist
Sigmund Freud developed a theory of personality and a system of
psychotherapy known as psychoanalysis. According to this theory,
people are strongly influenced by unconscious forces, including
innate sexual and aggressive drives.
Sigmund Freud tried to make a solid science of
human behavior. Â“Have you not noticed,Â” he wrote early in the
century, Â“that every philosopher, every imaginative writer, every
historian and every biographer makes up his own psychology for
himself, brings forward his own particular hypotheses concerning the
interconnections and aims of mental acts Â– all more or less
plausible and all equally untrustworthy? There is an evident lack of
any common foundation.Â” Freud tried to establish a foundations solid
as the foundations in physics and chemistry.
Freud worked by introspection, which is
looking from the outside inward. For Freud the brain was a black
box. When he spoke about the unconscious workings of the mental
apparatus, he added a warning for his readers: Â“I must beg of you no
to ask what material it is constructed of. That is not a subject of
psychological interest. Psychology can be as indifferent to it as,
for instance, optics can be to the question of whether the walls of
a telescope are made of metal or cardboard.Â” Â“We must recollect,Â”
Freud once admonished his followers, Â“that all our provisional ideas
in psychology will presumably one day be based on an organic
substructure.Â” But Freudians and virtually of the schismatic sects
that split away from the Freudians studied the psyche strictly from
the top down and the outside in. One psychologist wrote that as far
as he was concerned the skull could be full of cotton.
Freud and his followers argued that an
individualÂ’s problems are determined more by experience than by
wiring as did the behaviorists.
SC. He studied at
became professor of psychology at Johns Hopkins University
(1908-20), where he established an animal research laboratory. He
became known for his behaviorist approach, which he later applied to
human behavior. In 1921 he entered advertising, and wrote several
general books on psychology.
Abandoned introspection and the abstract study of consciousness
Studied psychology from a functionalist perspective, which gave rise
Viewed behavior holistically: not simply a function of
'consciousness', nor just physiological events
we could control human behavior as an engineer controls a machine
Developed a way of assessing the suitability of military candidates
for World War I
Mapped out the major categories of behavior: explicit and implicit,
hereditary (emotions and instincts) and acquired.
(1884 Â– 1952)
Clark Hull grew up handicapped and
contracted polio at the age of 24, yet he became one of the great
contributors to psychology. His family was not well off so his
education had to be stopped at times. Clark earned extra money
through teaching. Originally Clark aspired to be a great engineer,
but that was before he fell in love with psychology. By the age of
29 he graduated from Michigan University. When Clark was 34 when he
received his Ph.D. in Psychology at the University of Wisconsin in
1918. Soon after graduation he became a member of the faculty at the
University of Wisconsin, where he served for 10 years. His life long
emphasis was on the development of objective methods for
psychological studies designed to determine the underlying
principles of behavior.
Hull devoted the next 10 years to the
study of hypnosis and suggestibility, and in 1933 he published
Hypnosis and Suggestibility, while employed as a research professor
at Yale University. This is where he developed his major
contribution; an elaborate theory of behavior based on Pavlov's laws
of conditioning. Pavlov provoked Hull to become greatly interested
in the problem of conditioned reflexes and learning. In 1943 Hull
published, Principles of Behavior, which presented a number of
constructs in a detailed Theory of Behavior. He soon became one of
the most cited psychologists.
Hull believed that
human behavior is a result of the constant interaction between the
organism and its environment. The environment provides the stimuli
and the organism responds, all of which is observable. Yet there is
a component that is not observable, the change or adaptation that
the organism needs to make in order to survive within it's
environment. Hull explains, "when survival is in jeopardy, the
organism is in a state of need (when the biological requirements for
survival are not being met) so the organism behaves in a fashion to
reduce that need" ( Schultz & Schultz, 1987, p 238). Simply, the
organism behaves in such a way that reinforces the optimal
biological conditions that are required for survival.
Hull was an
objective behaviorist. He never considered the conscious, or any
mentalistic notion. He tried to reduce every concept to physical
terms. He viewed human behavior as mechanical, automatic and
cyclical, which could be reduced to the terms of physics. Obviously,
he thought in terms of mathematics, and felt that behavior should be
expressed according to these terms. "Psychologist must not only
develop a thorough understanding of mathematics, they must think in
mathematics" (Schultz & Schultz, 1987, p 239). In Hull's time three
specific methods were commonly used by researchers; observation,
systematic controlled observation, and experimental testing of the
hypothesis. Hull believed that an additional method was needed, -
The Hypothetico Deductive method. This involves deriving postulates
from which experimentally testable conclusions could be deduced.
These conclusions would then be experimentally tested.
Hull viewed the
drive as a stimulus, arising from a tissue need, which in turn
stimulates behavior. The strength of the drive is determined upon
the length of the deprivation, or the intensity / strength of the
resulting behavior. He believed the drive to be non-specific, which
means that the drive does not direct behavior rather it functions to
energize it. In addition this drive reduction is the reinforcement.
Hull recognized that organisms were motivated by other forces,
secondary reinforcements. " This means that previously neutral
stimuli may assume drive characteristics because they are capable of
eliciting responses that are similar to those aroused by the
original need state or primary drive" (Schultz & Schultz, 1987, p
240). So learning must be taking place within the organism.
theory focuses mainly on the principle of reinforcement; when a S-R
relationship is followed by a reduction of the need, the probability
increases that in future similar situations the same stimulus will
create the same prior response. Reinforcement can be defined in
terms of reduction of a primary need. Just as Hull believed that
there were secondary drives, he also felt that there were secondary
reinforcements - " If the intensity of the stimulus is reduced as
the result of a secondary or learned drive, it will act as a
secondary reinforcement" ( Schultz & Schultz, 1987, p 241). The way
to strengthen the S-R response is to increase the number of
reinforcements, habit strength.
Mathematico Deductive Theory of Behavior relied on the belief that
the link between the S-R relationship could be anything that might
effect how an organism responds; learning, fatigue, disease, injury,
motivation, etc. He labeled this relationship as "E", a reaction
potential, or as sEr. Clark goal was to make a science out of
all of these intervening factors. He classified his formula
sEr = (sHr x D x K
x V) - (sIr + Ir) +/- sOr
as the Global Theory of Behavior. Habit strength, sHr, is
determined by the number of reinforces. Drive strength, D, is
measured by the hours of deprivation of a need. K, is the
incentive value of a stimulus, and V is a measure of the
connectiveness. Inhibitory strength, sIr, is the number of
non reinforces. Reactive inhibition, Ir, is when the organism
has to work hard for a reward and becomes fatigued. The last
variable in his formula is sOr, which accounts for random
believed that this formula could account for all behavior, and that
it would generate more accurate empirical data, which would
eliminate all ineffective introspective methods within the
laboratory (Thomson, 1968).
Although Hull was
a great contributor to psychology, his theory was criticized for the
lack of generalizability due to the way he defined his variables in
such precise quantitative terms. "Thus, Hull's adherence to a
mathematical and formal system of theory building is open to both
praise and criticism" (Schultz & Schultz, 1987, p 242).
Skinner, B(urrhus) F(rederic) (1904-1990)
American psychologist B. F. Skinner became
famous for his pioneering research on learning and behavior. During
his 60-year career, Skinner discovered important principles of
operant conditioning, a type of learning that involves reinforcement
and punishment. A strict behaviorist, Skinner believed that operant
conditioning could explain even the most complex of human behaviors.
= ordinary behavior, it looks free but the controls are hidden in
the consequences. It seems to be uncaused because the behavior has a
prior history of reinforcement. Operant behavior is shaped. The
cause for operant behavior is a history of shaping.
= differential reinforcement for successive approximations that have
been generated by extinction induced variability.
= behavior that successively (1 after another) approximates (gets
closer and closer) to one goal.
= reinforcing some behaviors and not others.
= Strengthen (not reward).
approximations closer to what you want. Prior behaviors are no
longer reinforced and put through extinction. Your behavior evolves
in response to the environment. A response if affected by its
consequences Â– actually a biological response to the consequences.
New behavior comes from extinction of old behavior.
an operant: The modifiability of the response with changes in
consequences. Therefore, to show a behavior is an operant, you must
show that it is modifiable. Behavior conforms to contingencies; the
response comes to conform.
Operant Behavior: A class of responses which produce a common effect
on the environment. The frequency of occurrence of members of the
class are subject to modification such that there will develop an
increased correlation/correspondence between members of the
response class (producing a particular outcome) and the frequency of
Reflex: Unlearned correlation between a class of stimuli and a class
of responses. ItÂ’s not a stimulus alone, nor a response alone. Also,
itÂ’s a correlation between a group of stimuli and responses, e.g.
different types of pepper = sneezing.
Classical Conditioning: (conditional reflex) correlate a neutral
stimulus with an unconditioned stimulus to create a conditioned
reflex. Ex. You pair (correlate) a bell with food. Bell will elicit
response that food did, i.e. salivation.