Personality is the complex interplay of an individual’s socio-physiological traits and attributes, which are manifested, in the unique adjustment to his social environments.
The definitions hereunder as given by some competent authorities in the subject will suffice to explain the concept of personality better:
1. “Personality is the dynamic organization within the individual of those psycho-physical systems that determine his unique adjustment to his environment”. (G.W. Allport: “Personality”, New York Holt 1937).
2. In the words of J.F. Dashiell, “Personality is man’s system of reaction and reaction possibilities as viewed by fellow members of society; it is the sum total of the behaviour traits manifested in his social adjustment”.
3. According to T. L. Engel and Louis Snellgrove, “Personality is the sum total of an individual’s relatively consistent, organized and unique reactions to the environment”.
From the above definitions, we deduce that personality is a person’s peculiar and enduring psycho-physical traits and attributes, which determine his adjustment to his social environment, and which make him unique and easily distinguishable among other persons.
The above definitions and meaning of personality will enable us to effectively analyse how personality development takes place. The analysis of personality development involves the understanding of the processes by which individuals acquire and build up those peculair traits and attributes, which make them easilu distinguishable among other individuals.
Man being a complex product of biogenic and sociogenic integration, it is the continuous interplay and development of these two factors that determine the kind of personality he develops into. Thus, many factors, such as intellectual ability, heredity and social factors, influence the development of human personality.
Specifically, the two known factors involved in personality development are:
1. The Biological (Genetic) Factors And
2. Social Or Environmental Factors
Biological Or Physiological (Genetic Factors)
At the time of birth, every human individual is already predisposed to certain inherent biological traits that are bound to influence the development of his/her personality either adversely or positively. One such outstanding biological factors is the hormone secreted by the Endocrine glands, or the glands, of internal secretion, or the ductless glands, as they are sometime called. The hormones secreted by these glands are directly delivered into the blood stream. The effects of these hormones are capable of raising or lowering the activity (metabolic system) level of the body system or certain organs therein. To better understand the important role of the endocrine system on the body and its influence on personality development, a brief explanation of some of these important glands is necessary.
1. The Pituitary Gland: This is a small grape-sized structure hanging from the base of the brain. One important role of the pituitary gland is the control of bodily growth. The pituitary secretes a set of hormones that regulates the rate of development. If too little growth hormone is released when an individual is still growing, the person may suffer a growth failure called dwarfism. Too mich growth hormone at this period leads to giantism. Excessive secretion of the growth hormone toward the end of the growth period leads to the condition known as acromegally, which is characterized by large arms, hands, feet, facial bones and general distortion in appearance, giving a previously normal person a gorilla-alike shape.
Somatotropin is the best known growth hormone of the pituitary gland. Its deficiency at infancy results in midget, which is a miniature adult.
The Pituitary also regulates the functioning of other glands, including the ovaries and testes. These glands in turn regulate such bodily processes as reproduction, metabolism and responses to stress. In women, the pituitary also controls the production of milk during pregnancy. Because of its many functions and effects, the pituitary is often called the “Master gland”. But the hypothalamus, which lies directly above the pituitary in the brain, directs and controls the activity of the pituitary, and hence other glands; this serves as the major link between the brain and the glandular system (Schally et al, 1977).
2. Thyroid Gland: This gland is located at the base of the neck, on each side of the windpipe. This glands secretes the hormone called thyroxin, which regulates the metabolic rate of the body. As a result, it can exert some effects on personality. A person with an over active thyroid gland (termed hyperthyroidism) tends to be thin, tense, excitable and nervous. An under active thyroid (hypothyroidism) in an adult causes sleepiness, inactivity, dullness and overweight. An extreme deficiency may lead to myzeodema and colloid goiter. While in infancy, it limits the development of the nervous system and can lead to severe mental retardation and a condition known as Cretinism. The principal ingredient of the thyroxine is iodine. Myxoedema is characterized by puffy skin, inert muscles and brain, and the individual becomes forgetful and unable to concentrate or to think and act effectively.
3. The Adrenal Glands: Located on top of the kidneys, the adrenal glands secrete two different sets of hormones. The adrenal modular or inner core of the glands produces two hormones – adrenaline and noradrenaline. These two hormones are responsible for the important changes, such as increase in heart-beat, blood pressure, release of stored sugar into the blood stream and preparedness of the blood to clot more quickly in the event of injury.
The adrenal cortex, or outer “bark” of the adrenal glands, produces another set of hormones called corticoids. One of the important jobs of these hormones is the regulation of salt balance in the body. The corticoids also help the body to adjust to stress. They also serve as a secondary source of sex hormone. The anabolic steroids used by some athletes to “bulk up” or promote muscular growth for strength, are the synthetic versions of one of the male corticoids. An over-secretion of the cortical sex hormones can cause virilism, in which case a woman grows bears, or a man’s voice becomes so low to be understood. Over secretion in children may lead to premature puberty, resulting in full sexual development and maturity at very tender age. One of the remarkable cases of such early sexual maturity is that of a five year old Peruvian girl who gave birth to a son (Strange, 1965).
4. The Pancreas: This glands has two secretions. The commonly known pancreatic juice is not an internal secretion because it passes from the gland into the intestine where it acts on the food and plays an important part in digestion.
However, there is another secretion of the pancreas that is directly discharged into the blood stream. It is a very important hormone known as Insulin. The insulin passes to the muscles through the blood stream and enables the body to convert sugar into fuel, i.e. Oxidation or burning of sugar for sugar. Failure of the pancreas to secrete insulin results to diabetes, a condition in which unoxidized sugar accumulates in the blood till it ir removed by the Kidneys.
Variation in the output of insulin is the major cause of variations in the individual’s level of blood sugar, which plays an important role on the personality and behaviour of individuals, if the blood sugar falls below certain level, mental function is impaired (adversely affected) and alteration in personality result. The most outstanding ones include changes in mood, increased irritability and vague feelings of apprehension.
Besides the endocrine systems, other biological factors such as physical structure, body chemistry, etc., also affect personality. It is obvious that one’s physical size, fitness, etc., help to determine one’s relationship with others and the type of attitude one adopts under social situations. Also, presence of certain chemicals in the body, have been known to exert some influence on individual’s personality traits.
Prolonged and acute illness can also leas to a marked change in personality. Encephalitis is an example of such disease. According to experts, it gives rise to exaggerated emotionality and irritability with over-activity and impulsiveness.
The socio-environmental factors that influence the development of personality follow the process of social learning through interaction with others; and this begins to take place immediately after birth. It is through this process of social interaction that the biological traits inherent in man are transformed to social realities, thus, giving real form to the complex and complete personality of the individual. The social factors through which this development takes place include the following:
1. The family or Home environment and the neighbourhood
2. School and peer groups
3. The entire society environment.
1. The Home Or Family is the very first social environment an individual comes in contact with at the beginning of his life. As the individual child begins to attain maturity, he identifies himself with members of the family. Through the process of socialization, the child learns and acquires certain social traits and behaviours. He or she also acquires certain basic principles and values of life based on the cultural, educational, religious and economic backgrounds of the family. At this stage of personality development, the developing individual learns by imitating the parents and other members of the family and those within the neighbourhood whom he or she identifies as models. All these social traits will later form part of the individual’s personality attribute, which disposes him/her to cope with his/her social environment.
The differences in socialization in different family settings and backgrounds go along way to accounts for individual differences in personality among persons of the same social group and community; just the same way as genetic composition and position in birth order, may help to account for the personality differences among siblings of the same family and parentage.
2. The School And Peer Group, become the next important agencies in personality development during later stages of childhood and adolescence. At the school environment and other such places of learning, the developing individual becomes more exposed and closer to the realities of certain values and principles of life outside the family system. He or she tries to make adjustment in order to fit in within the larger social system as he or she begins to associate with other people from different family and cultural backgrounds. Directly and indirectly, the teachers and member of his different peer groups begin to exert influence on his family-based values and principles. Some of these principles and values are either donw away with, or modified as the individual tries to adjust to the school environment and peer group influences and values.
3. The Entire Society Environment, also plays its own role on the development of individual’s personality. Society is a large group of people who share common ways of life and values. As individuals grow older, they become more exposed to social lives and values, which help to mould their personality to a more complex and sophisticated one. By exposure to different skills, professional groups and other formal institutions and organizations, an individual acquires those personality traits, which enables him or her to cope with more complex social situations and to perform different roles in the group he belongs to. Besides, the individual also becomes aware of the difference between the society he or she belongs to and other societies, and learns how to influence others through his social exposure and experiences.
It may suffice to say that the various socialization processes and stages, which an individual passes through, are the major socio-environmental factors that influence his personality development. Socialization having been defined as a “process of human development from biological to social being through the process of learning and interaction. Thus, as one passes through and interacts with the various informal and formal agencies of socialization, he acquires certain personality traits and attributes that make him unique in his social adjustment. For instance, such informal agencies of socialization, like the family, peer groups, neighbourhood, etc., and formal ones like educational institutions, cultural/socail organizations, etc, serve as agencies or media of socialization and personality development.
Personality Type Theories
William Sheldon’s Personality Type
The theory of personality type based on body structure or physique expressed in the writing of a German Psychiatrist (Kretschmer), was modified by William Sheldon, an American who classified personality into three components of body build as follows:
i. Endomorphy: Which refers to the relative predominance of softness and roundness throughout the body. The endomorphs appear fat with flabby muscles. They love eating because of their well-developed digestive system. They tend to be apprehensive and insecure which makes them behave like conformist.
ii. Mesomorphy: Individuals having mesomorphic physique are characterized with massive, solid and well developed muscles, bones and joints. They tend to be bold, love sports, physical exercises and adventure.
iii. Ectomorphy: According to Sheldon, people of this body buid are predominantly linear and fragile. They have slender limbs and bodies. They are very analytic and critical of others, inhibit their feelings, sensitive and prefer solitude to mixing up.
Like Kretshmer, Sheldon maintained that there exists a close relationship between physique and temperament and between physique and psychosis (mental problem).
The psychological type of personality theory was pioneered by William James. But it was popularized by Gustarv Jung, a Swiss psychologist whose concept of “introversion – extroversion” personality types became a general concept of personality.
According to Jung, personality can be divided into two psychological types:
1. Introversion: This implies turning inward interest and energies with highest values being placed on subjective or personal factors. An introvert, according to Jung, is an individual who habitually thinks, feelds and acts in a way that demonstrates that he is motivated chiefly by his own ideas and self principles than by objective or material values in their behaviour.
The common characteristics of introverts are as follows
a. Behaviours are determined by subjective and idealistic considerations
b. They are quiet, aloof and prefer solitude.
c. They are rigid and live by rules and ideas.
d. Touchy, sensitive and suspicious.
e. Emotionally reserved and self-analytic.
2. Extroversion: Extroversion implies direction of interests and energies outward, with high values being placed on external material objective. Extroverts habitually think, feel and act in relation to external objects. Their common traits and characteristics are as follows;
i. Behaviour determined by objective environment.
ii. Talkative, good mixer, confiding and prefer company.
iii. Adaptable, conduct governed by the need of the time (expendiency)
iv. Indifferent to criticism, not suspicious.
v. Emotionally uninhibited, warm-hearted, impulsive and rarely self-analytical.
According to Jung, those who manifest the combined characteristics and traits of both the introvert and the extrovert are referred to as ambiverts.
Trait Theories Of Personality
A trait is a psychological construct or personality dimension approach on the basis of which individuals may be placed according to how much of the characteristic they posses. In most case, traits are continuous dimensions, ranging from one extreme (e.g. extremely strong) to the opposite extreme (extremely weak). A given individual may fall or be placed at any point in between the two extremes.
According to J.P. Guilford, “A trait is any distinguishable, relatively enduring way in which one individual varies from another” (1959 .p.6).
Allport’s Trait Theory
Gordon W. Allport (1937, 1961, 1966) became the most influential of the trait theorists. He postulated that “traits are the building blocks of personality, the guideposts for actions, the source of uniqueness of the individual. According to him, “traits are inferred predispositions that direct the behaviour of an individual in consistent and characteristic ways. In addition, traits produce consistencies in behaviour because they are enduring attributes and they are general and broad in their scope. That means that thet stand between and unify a variety of specific stimuli and responses.
Allport identified three types of traits which include:
1. Cardinal traits, which he said, are highly generalized dispositions around which a person organizes his or her whole life. For some, it may be power or achievement, while some others may be disposed toward self-sacrifice for the good of others.
2. Central traits: These traits are never the less, broad and general in their influence, but they are less dominant and are in less total control of behaviour.
3. Secondary traits, are those specific ones that guide our actions in more limited channels and situations.
According to Allport, traits form the structure of personality, which in turn determine an individual’s behaviour. He saw personality structure rather than environmental conditions as the critical determiner of psychological reality. “The same fire that melts the butter hardens the egg”. Allport used this expression to show how the same stimuli have different effects on different individuals. Although he recognized common traits that were shared by individuals in a given culture. Allport was most interested in discovering the unique traits that made each person a singular entity.
In a later paper he presented in 1966, he made it clear that the core concept of “traits” was basic, general term covering all the permanent possibilities for human action”. These include long-range sets, attitudes, “perceptual response disposition”, and cognitive styles”.
As the “most acceptable unit for investigation in psychology of personality” (1937), Allport saw traits as “biophysical facts” – the personal realities whereby neural and mental energies affect how we think, feel and act.
Besides Allport, other three notable trait theorists include; Raymond Cattell (1965), J.P. Guilford (1959), and the British Psychologist, Hans Eysenck (1967, 1973). It was the last mentioned that developed a personality inventory that can be used to identify people who vary along the trait dimension of extraversion – introversion.
Criticisms Of Trait Theories
The main grounds on which the trait theories have been criticized are that:
1. They do not explain the causal determinants of behaviour, but merely identify trait labels that are correlated with behaviour.
2. Further more, trait theories offer no conception of the development of personality. Rather, emphasis is only placed on the structure of personality and its elements, without corresponding concern for its origins or the dynamic interrelation of the traits that are assumed to interplay to form personalities.
However, a positive value of the trait theory lies in the fact that it recognizes that predictions of behaviour are usually improved by taking account of both situational variables and dispositional variable; that is, the inherent and acquired traits of the individual.