Definition and Significance of
the study of Psychology
Psychology is derived from two Greek words: psyche
and logos meaning soul and study. To the Greeks
psychology is simply a study of soul. Psychology is defined
as the scientific study of the behaviour of living organisms,
with special attention to human behaviour.
Behaviour means activities that can be observed
objectively such as the reactions of the muscles and the glands
as well as a recognized pattern as the whole. It also includes
the internal processes such as thinking, feeling, and other
reactions which cannot be directly observed but can be
inferred from external behaviour. Behaviour may be classified
as overt or covert. Sometimes, these processes are called
intrinsic or extrinsic behaviour.
Characteristics of science:
1. Dependence on observation. Science insist on observing under many
different circumstances; it insist on having many different individual cases
observed and also on having more than one observer. It also demands that
records be kept.
2. Law of parsimony. It states that when two possible explanations are both
adequate, the simpler one should be chosen. Simpler in terms of number of
unverified assumptions it makes.
3. Objectivity. Objectivity Is obtained when there are unbiased conclusions as a
result of open-mindedness, observing the same thing the number of times
before reaching a conclusion, agreement in the observation made by different
scientist, and a carefully kept accurate records.
4. Knowing for the sake of knowing. Pursuing questions in science not because
we expect useful results, but because we are curious about the answer, whether it
will be useful or not.
What Psychology is Not:
1. Psychology and the mysterious. Many people imagine that psychology is
something magical or mysterious and somehow psychologist have a superior
and almost superhuman way of looking into thoughts and feelings of a
2. Psychology and “common sense”. For some people, psychology is
essentially nothing more than common sense.
3. Psychology and pseudo sciences. People sometimes confuse psychology
with a whole group of endeavours which have come to be known as pseudo
The Beginnings Of
Aristotle, who live in the 4th century, B.C. Was one of the earliest writers to
devote his attention to psychology. He believe that at birth, the mind is a tabula
rasa, a blank sheet, and that the experiences an individual encounters during his
life time are impressed on the mind. Aristotle suggested that there are three
principles of memory: Similarity, Contrast, and Contiguity.
After the Greeks, St. Augustine is considered the next great precursor of the
modern psychologist because of his skills in introspection and his great curiosity
about psychological phenomena, including observations on young infants and on
crowds at chariot races.
Rene Descartes (1596-1650) left his mark on the history of psychology
through his theory that animals are machines that can be studied much as other
machines are studied. He introduced the concept of Reflex-Action, which has
had significant place in both physiology and psychology.
By the 19th century, a group of German philosophers started to use scientific
methodology in there psychological studies.
Wilhelm Wundt, establish the first psychological laboratory in Leipzig in 1979
and commonly called the founder of modern experimental psychology.
Two theories of mind competed for psychologist support .
The first one is the faculty psychology, was a doctrine of mental powers.
According to this theory, the mind has few principal faculties such as thinking,
feeling and willing that accounted for it’s activities.
The second one is the opposing theory. They denied the inborn faculties of
the mind; instead, they limited the mind’s content to ideas coming by way of the
senses, which then become associated through principles such as similarity,
contrast and contiguity.
Hermann von Helmholtz, contributed to the ultimate development of
psychology. Helmholtz measured the speed of the nerve, set forth a theory of
colour vision, and offered an explanation for our perception of musical tones.
Ernst B. Weber (1975-1878). His experiments produced a generalization
known as Weber’s Law. He found that the smallest detectable differences between
weights depended on the ratio between the weights, not their absolute sizes.
Gustav T. Fechner ( 1801-1887). He extended and gave publicity to Weber’s
findings in a famous book of Psychophysics publish in 1860. Fechner saw that, by
changing a physical stimulus slowly and nothing the steps of judgements expressed
a relationship can be established between a physical series and psychological series.
The methods Fechner invented known as the psychophysical methods, determined
psychology’s first laboratory procedures.
Bessel the Astronomer at the Konigsberg Observatory, study what he called
the “personal equation” of different astronomers. He collected data from several
trained persons and studies the errors made in their reports. Bessel concluded that
each astronomers had his “personal equation” and that real differences between
astronomers were usually found. The difference in the estimates of observers
came to be known as difference in reaction time.
In 1884 Sir Francis Galton establish his anthropometric laboratory in London
where he gave test to people who came into his laboratory, Galton confirmed and
extended the findings of Bessel. Galton also invented the statistical technique of
correlation and developed the index to be named the coefficient of correlation.
Charles Darwin (1809-1882). Darwin’s theory establish the continuity between
animal and man, it made comparative psychology important.
Another body of influence upon psychology came from medicine and
psychiatry, especially from the treatment of the mentally ill. It started with the
work of Frenchman Anton Mesmer (1734-1815) on hypnotism and later to the
work of the Viennese physician Sigmund Freud (1856-1935), the founder of that
branch medical psychology known as psychoanalysis.
The first formal laboratory was set up at the John Hopkins University in 1833.
The first American leader in psychology was William James (1842-1910) who has
considered as the “Dean of American Psychologist.”
In 1885, Herman Ebbinghaus reported his studies of learning and memory
which were directly inspired by Fechner’s measurement of sensation.
Carl G. Jung
Sigmund Freud Alfred Binet
• Was developed in Germany in the 19th century. It’s main leaders were
Wilhelm Wundt and later, Edward Bradford Titchener. The structuralists
were primarily concerned with discovering the structure of the mind. They
believe that the mind to be made up of building blocks in the form of
various types of sensation and perception, and these building blocks could
be discovered through introspection or looking into one’s own mind.
• As the center of psychological study shifted the United States, a
new school known as functionalism arose. It’s three main leaders
were James R. Angell, John Dewey, and Harvey Carr. The most
important contribution of functionalism was in changing the
focus of psychology to learning, motivation, and thinking, and
away from the structuralist’ emphasis of individual perception and
• Sigmund Freud, a famous physician and psychiatrist, attempted to
find the cause and cure of personality disorders. He postulate the
existence of unconscious mental processes which influenced the
individual’s behaviour in various indirect ways.
• The school of behaviourism was founded by John B. Watson who finish his
Ph.D. from the University of Chicago. Watson Criticized both the
structuralists and the functionalist for their use of introspection as a
technique. He argued that psychologist should use only objective methods
and that their observations and measurement should be in such form that
they could be checked and verified by other psychologist. He pointed out
that the knowledge of introspection is not subject to verification by any
Gestalt (Pattern or Configuration)
• Max Wertheimer founded the gestalt school which maintained
that psychology should study the whole pattern and behaviour or
experience or the perception of organized configuration. It’s
fundamental principle states that the whole is more than the sum
of all it’s parts.
• In Duke University of Durham, North Carolina, William
McDougall conducted researches in the field of psychology. He
believes that objects, movements and behaviour have definite
purpose and that the ductless glands in man produce hormones
which give him purpose. The importance of hormones in life
made Purposivism be called “hormic” psychology.
• Explains the underlying principles of human behaviour. The
study of how and why people behave this way or that way and the
principles of the structural and functional mechanisms of the
human body are discussed.
• Is that branch of psychology which treats of the behaviour and
mental processes of the different species. This is also known as
the animal psychology where the activities of both man and
animals are compared and differentiated, particularly in relation to
generic and evolutionary theory.
Developmental and Genetic Psychology
• Concerns itself with the study of human behaviour in all of its
aspects with growth and development. The entire life of
individual which is divided into the stages of prenatal, neonatal,
infancy, childhood, adolescence, adulthood and senescence are
scientifically presented with its physical, mental, emotional, social
and moral development during the period.
• Is the scientific study of human behaviour from its prenatal
beginnings up to early adolescence. This science deals with the
stages of growth and maturation , the effects of environmental
influences upon individual patterns of development, and the
psychological and social interaction between the child and the
society into which he is born and in which he is reared.
• Is the study of behaviour from puberty to later life. It involves the
physical and mental maturation of an individual, as well as the
attainment of emotional and social maturity.
• Is the scientific study of human behaviour in old age.
• Is that study of etiology or cause of personality defects, or that
man’s behaviour which deviates from the average reaction, hence
• Deals with the observations and the experiments in a
psychological laboratory in the investigation of different types of
behaviour, the aim of which the understanding of the
fundamental causes of behaviour.
• Is a branch of study which investigates differences and similarities
existing between individuals, social groups, and races.
• Is a scientific interpretation of mental phenomena emphasizing
internal drives and motives as the cause of behaviour. In
contemporary psychology, this is also referred to as personality
psychology, which is largely concerned with understanding of the
non-deviant individual case.
• Is the branch which investigate the functions of the different
organs of the body, especially the nervous system and their
bearing on behaviour and mental processes.
• Are found in medicine, education, law, business and industries,
and many fields in society.
• Is a field of specialization concerned with Psychological aspects
of teaching and of formal learning processes in schools.
Important laws of learning useful in effective instruction are put
• Psychology as applied in medicine is called psychiatry. It concerns
with the treatment of mental deseases.
• Is the application of the principles of human behaviour in law, or
any legal proceedings. Psychological facts are employed by lawyers
in their professional goals. It deals with the testimony and
evidences, the examination of witnesses, study of individual
delinquent and criminal and with problems of the law.
• Pertains with the diagnosis and evaluation of the symptoms and
records of events relevant to the condition of the person who
has a problem. In this field there are three kinds of specialists
who do and applied clinical work: psychiatrist, psychoanalyst and
• Deals particularly with the behaviour of the consumers.
Psychological methods are employed to gain more customers.
And impress prospective buyers.
Industrial and Engineering Psychology
• Is a branch of applied psychology which investigates the problem
and situations found in firms, and industries, as personnel
management and administration. It deals with the improvement
of the efficiency of employees and the promotion of the welfare
of the management.
There are six well-known method used in psychology. Although
they are not use at all times, a knowledge of this approaches will help
one in choosing the most suitable way to get all facts and the most
effective technique in a particular situation or study.
• A subject method of observation which has introduce by St.
Augustin. In this process of mental self-analysis, the psychologist
studies himself, records his own feelings and experiences, analyses
this experiences and later interprets them.
• Is the most widely used in the study of behaviour. There are
several kinds of observation: uncontrolled or informal
observation, naturalistic observation, controlled or formal
• Psychological research makes used of life-history methods, which
involve extensive studies of individuals by tracing the
development of a particular form of behaviour. The life-history
methods are of three basic forms: the day book method, the
clinical method, or the biographical method.
Survey Method or the Group Method
• Through written questionnaires or interviews, data are obtained
from a large group, particularly the group which will constitute
the representative sample. This is used in obtaining norms,
surveys, or opinion polls.
• This is used to study behaviour which can be brought into the
laboratory and studied under controlled conditions. It involves
variables that can be measured and varies quantitatively.
• Statistics is the science that deals with the collecting and handling
numerical data, and making interferences from such data. A
knowledge of methods of statistics is needed for understanding
the tests to appraise individuality such as intelligence tests,
personality tests and many appraisal devices.
Objectives of Psychology as a
Psychology as a science has certain objectives, which are to
understand, predict, and control behaviour. After various observation,
the psychologist classifies his facts into meaningful categories on the
basis of stated aspects of similarity. This is the first goal of
understanding. The class of classification employed are: qualitative and
• Is one wherein items are grouped into categories on the basis of
some particular quality or characteristics they have in common.
Students, for example are classified as freshmen, sophomores,
etc.; as males or females; as single or married; as Liberals or
Nationalist; as professional students or working students.
• Is one wherein categories are determined on the basis of some
characteristics which is present in different degrees and this is
measurable on mathematical scale. The prerequisite to quantitative
classification is measurements.