Psychology is the scientific study of mental processes
and behaviour. Psychologists observe and record how people and other animals
relate to one another and to the environment. They look for patterns that
will help them understand and predict behaviour, and they use scientific
methods to test their ideas. Through such studies, psychologists have
learned much that can help people fulfill their potential as human beings
and increase understanding between individuals, groups, nations, and
Psychology is a broad field that explores a variety of questions about
thoughts, feelings, and actions. Psychologists ask such questions as: "How
do we see, hear, smell, taste, and feel? What enables us to learn, think,
and remember, and why do we forget? What activities distinguish human beings
from other animals? What abilities are we born with, and which must we
learn? How much does the mind affect the body, and how does the body affect
the mind? For example, can we change our heart rate or temperature just by
thinking about doing so? What can our dreams tell us about our needs,
wishes, and desires? Why do we like the people we like? Why are some people
bashful and others not shy at all? What causes violence? What is mental
illness, and how can it be cured?"
The research findings of psychologists have greatly increased our
understanding of why people behave as they do. For example, psychologists
have discovered much about how personality develops and how to promote
healthy development. They have some knowledge of how to help people change
bad habits and how to help students learn. They understand some of the
conditions that can make workers more productive. A great deal remains to be
discovered. Nevertheless, insights provided by psychology can help people
function better as individuals, friends, family members, and workers.
Psychology and other sciences
Psychology is closely related to the natural science of biology. Like many
biologists, psychologists study the abilities, needs, and activities of
human beings and other animals. But psychologists focus on the workings of
the nervous system, especially the brain.
Psychology is also related to the social sciences of anthropology and
sociology, which deal with people in society. Like anthropologists and
sociologists, psychologists investigate the attitudes and relationships of
human beings in social settings. These three academic disciplines often
study the same kinds of problems from different perspectives. However,
psychologists concentrate on individual behaviour. They are especially
interested in the beliefs and feelings that influence a person's actions.
In addition, psychology is similar to a medical field called psychiatry.
Most psychologists have a degree in psychology and may or may not specialize
in the treatment of mental disorders. Psychiatrists, on the other hand,
usually have a medical degree and devote themselves to treating mental
Methods of psychological research
In their research, psychologists use much the same approach as other
scientists do. They develop theories, also called hypotheses, which are
possible explanations for what they have observed. They then use scientific
methods to test their hypotheses. The chief techniques used in psychological
research include (1) naturalistic observation, (2) systematic assessment,
and (3) experimentation.
Naturalistic observation involves watching the behaviour of human
beings and other animals in their natural environment. For example, a
researcher might study the activities of chimpanzees in the wild. The
psychologist looks for cause-and-effect relationships between events and for
broad patterns of behaviour.
Psychologists conducting such studies try to observe a group large enough
and typical enough to accurately reflect the total population. Such a group
is called a representative sample. Observers also attempt to keep their
personal views from influencing the study. In addition, psychologists try to
prevent their presence from affecting the behaviour being observed. A
careful scientist hides from sight or remains on the scene long enough to
become a familiar part of the environment.
Naturalistic observation is a valuable source of information to
psychologists. The research itself has less effect on the subjects'
behaviour than a controlled experiment does. But observation alone seldom
proves a cause-and-effect relationship between two or more events. As a
result, psychologists use naturalistic observation chiefly as an exploratory
technique to gain insights and ideas for later testing.
Systematic assessment is the general name for a variety of organized
(systematic) methods used to examine (assess) people's thoughts, feelings,
and personality traits. The chief types of systematic assessment include
case histories, surveys, and standardized tests.
A case history is a collection of detailed information about an
individual's past and present life. Nearly all clinical psychologists gather
case histories of their patients to help them understand and treat the
patients' problems. A psychologist who notices similar experiences or
patterns of thought in several case histories may gain insight into the
causes of certain emotional disorders.
A survey, also called a public opinion poll, is a study that measures
people's attitudes and activities by asking the people themselves. Surveys
provide information on political views, consumer buying habits, and many
other topics. A psychologist conducting a survey prepares carefully worded
questions. The researcher may interview participants personally or post
questionnaires to them. If the psychologist wishes to form general
conclusions, the survey must collect responses from a representative sample
A standardized test is an examination for which average levels of
performance have been established and which has shown consistent results. In
addition, uniform methods of administering and scoring the test must have
been developed. Psychologists use standardized tests to help measure
abilities, aptitudes, interests, and personality traits.
Still other tests, called projective tests, yield clues to a person's
inner feelings. In a Rorschach test, for example, the subject describes what
he or she sees in a series of inkblots. In the Thematic Apperception Test,
the subject invents a story about the characters in each of a series of
pictures. Psychologists can interpret responses on these tests as
expressions of an individual's personality.
Case histories, surveys, and standardized tests enable psychologists to
gather much information that they could not detect by naturalistic
observation. However, the accuracy of the information gathered depends on
well-designed studies and on truthful, complete responses from the
individuals who participate.
Experimentation helps a psychologist discover or confirm
cause-and-effect relationships in behaviour. In a typical experiment, the
researcher divides subjects at random into two groups. One group is called
the experimental group and the other the control group. For the experimental
group, the researcher changes one condition that is likely to affect the
subjects' behaviour and holds all other factors constant. The experimenter
does nothing to the control group. If the experimental group behaves
differently from the control group, the one condition changed probably
caused the difference.
Other experiments involve repeated testing of the same subjects under
different conditions. For example, a study might test how alcohol affects
people's driving. Each subject would take a driving test on a laboratory
simulator while sober and then repeat the test after drinking a prescribed
amount of alcohol. Any difference in performance would probably be due to
the alcohol consumed.
The experimental method enables scientists to test a theory under controlled
conditions. But many psychologists hesitate to form conclusions based only
on laboratory investigations. In many cases, people's behaviour changes
simply because they know they are part of an experiment.
Beginnings. Since ancient times, philosophers and people in general
have tried to understand why human beings and other animals behave as they
do. The origins of psychology are often traced to the ancient Greek
philosopher Aristotle, who was chiefly interested in what the human mind
could accomplish. Aristotle believed that the mind or soul, which the Greeks
called the psyche, was separate from the body. He thought the psyche enabled
people to reason and was the source of the highest human virtues. The word
psychology comes from the Greek words psyche (mind or soul) and logia
During the Middle Ages, scholars studied behaviour chiefly from a religious
rather than a scientific viewpoint. However, several philosophers of the
1600's and 1700's made contributions to the development of psychology. Rene
Descartes, a French philosopher, described the body and mind as separate
structures that strongly influenced one another. He suggested that the
interaction between body and mind took place in the pineal gland, a tiny
organ in the brain.
Descartes also believed that people were born with the ability to think and
reason. This doctrine, called nativism, was rejected in the late 1600's and
early 1700's by a group of philosophers called empiricists. These thinkers,
including Thomas Hobbes and John Locke of England, David Hume of Scotland,
and George Berkeley of Ireland, believed the mind is empty at birth. They
thought that knowledge of the outside world comes only through the senses,
and that ideas result from people's experiences in life.
Psychology becomes a science. In the mid-1800's, two German
scientists--the physiologist Johannes P. Muller and the physicist and
physiologist Hermann L. F. von Helmholtz--began the first systematic studies
of sensation and perception. Their work showed that the physical processes
underlying mental activity could be studied scientifically.
But psychology did not develop into a science based on careful observation
and experimentation until the late 1800's. In 1875, the American philosopher
William James founded what was probably the world's first psychology
laboratory. A similar laboratory was established in Germany in 1879 by
Wilhelm Wundt. Wundt, a philosopher trained in medicine and physiology, also
published the first journal of experimental psychology. The work of James
and Wundt marked the beginning of psychology as a distinct field separate
From the late 1800's until the 1930's, psychologists were divided about what
they should study and how they should study it. Four major schools
developed. These schools were (1) structuralism, (2) behaviourism, (3)
Gestalt psychology, and (4) psychoanalysis.
Structuralism grew out of the work of James, Wundt, and their associates.
These psychologists believed the chief purpose of psychology was to
describe, analyse, and explain conscious experience, particularly feelings
and sensations. The structuralists attempted to give a scientific analysis
of conscious experience by breaking it down into its specific components or
structures. For example, they identified four basic skin sensations: warmth,
cold, pain, and pressure. They analysed the sensation of wetness as the
combined experience of cold and smoothness.
The structuralists primarily used a method of research called
introspection. In this technique, subjects were trained to observe and
report as accurately as they could their mental processes, feelings, and
Behaviourism was introduced in 1913 by John B. Watson, an American
psychologist. Watson and his followers believed that observable behaviour,
not inner experience, was the only reliable source of information. This
concentration on observable events was a reaction against the structuralists'
emphasis on introspection. The behaviourists also stressed the importance of
the environment in shaping an individual's behaviour. They chiefly looked
for connections between observable behaviour and stimuli from the
The behaviourist movement was greatly influenced by the work of the Russian
physiologist Ivan P. Pavlov. In a famous study, Pavlov rang a bell each time
he gave a dog some food. The dog's mouth would water when the animal smelled
the food. After Pavlov repeated the procedure many times, the dog's saliva
began to flow whenever the animal heard the bell, even if no food appeared.
This experiment demonstrated that a reflex--such as the flow of saliva--can
become associated with a stimulus other than the one that first produced
it--in this case, the sound of a bell instead of the smell of food. The
learning process by which a response becomes associated with a new stimulus
is called conditioning.
Watson and the other behaviourists realized that human behaviour could also
be changed by conditioning. In fact, Watson believed he could produce almost
any response by controlling an individual's environment.
During the mid-1900's, the American psychologist B. F. Skinner gained much
attention for behaviourist ideas. In his book Walden Two (1948), Skinner
describes how the principles of conditioning might be applied to create an
ideal planned society.
Gestalt psychology, like behaviourism, developed as a reaction
against structuralism. Gestalt psychologists believed that human beings and
other animals perceive the external world as an organized pattern, not as
individual sensations. For example, a film consists of thousands of
individual still pictures, but we see what looks like smooth, continuous
movement. The German word Gestalt means pattern, form, or shape. Unlike the
behaviourists, the Gestaltists believed that behaviour should be studied as
an organized pattern rather than as separate incidents of stimulus and
response. The familiar saying "The whole is greater than the sum of its
parts" expresses an important principle of the Gestalt movement.
Gestalt psychology was founded about 1912 by Max Wertheimer, a German
psychologist. During the 1930's, Wertheimer and two colleagues took the
Gestalt movement to the United States.
Psychoanalysis was founded during the late 1800's and early 1900's by
the Austrian doctor Sigmund Freud. Psychoanalysis was based on the theory
that behaviour is determined by powerful inner forces, most of which are
buried in the unconscious mind. According to Freud and other psychoanalysts,
from early childhood people repress (force out of conscious awareness) any
desires or needs that are unacceptable to themselves or to society. The
repressed feelings can cause personality disturbances, self-destructive
behaviour, or even physical symptoms.
Freud developed several techniques to bring repressed feelings to the level
of conscious awareness. In a method called free association, the patient
relaxes and talks about anything that comes to mind while the therapist
listens for clues to the person's inner feelings. Psychoanalysts also try to
interpret dreams, which they regard as a reflection of unconscious drives
and conflicts. The goal is to help the patient understand and accept
repressed feelings and find ways to deal with them.
Modern psychology has incorporated many teachings of the earlier schools.
For example, though many psychologists disagree with certain of Freud's
ideas, most accept his concept that the unconscious plays a major role in
shaping behaviour. Similarly, most psychologists agree with the
behaviourists that environment influences behaviour and that they should
study chiefly observable actions. However, many psychologists object to pure
behaviourism. They believe that it pays too little attention to such
processes as reasoning and personality development.
Psychology today has continued to develop in several directions. A group of
extreme behaviourists called the stimulus-response school believe all
behaviour is a series of responses to different stimuli. According to these
psychologists, the stimulus connected with any response can eventually be
identified. As a result, stimulus-response psychologists regard behaviour as
predictable and potentially controllable.
Another group of psychologists, who are known as the cognitive school,
believe there is more to human nature than a series of stimulus-response
connections. These psychologists concentrate on such mental processes as
thinking, reasoning, and self-awareness. They investigate how a person
gathers information about the world, processes the information, and plans
A school called humanistic psychology developed as an alternative to
behaviourism and psychoanalysis. Humanistic psychologists believe
individuals are controlled by their own values and choices and not entirely
by the environment, as behaviourists think, or by unconscious drives, as
psychoanalysts believe. The goal of humanistic psychology is to help people
function effectively and fulfil their own unique potential. The supporters
of this approach include the American psychologists Abraham H. Maslow and
Carl R. Rogers.
Many psychologists do not associate themselves with a particular school or
theory. Instead, they select and use what seems best from a wide variety of
sources. This approach is called eclecticism.
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Kincher, Johnny. Psychology For Kids II: 40 Fun Experiments That Help You
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Myers, David G. Exploring Psychology. Worth, New York, 1990.