Environmental and parental experiences during childhood influence an individual's personality during adulthood. For example, during the first two years of life the infant who is neglected (insufficiently fed) or who is over-protected (over-fed) might become an orally-fixated person (Freud, 1905).
Freud's Tripartite Theory of Personality
Freud (1923) saw the personality structured into three parts (i.e. tripartite), the id, ego and superego (also known as the psyche), all developing at different stages in our lives.
These are systems, not parts of the brain, or in any way physical.
The id is the primitive and instinctive component of personality. It consists of all the inherited (i.e. biological) components of personality, including the sex (life) instinct – Eros (which contains the libido), and aggressive (death) instinct - Thanatos.
It operates on the pleasure principle (Freud, 1920) which is the idea that every wishful impulse should be satisfied immediately, regardless of the consequences.
The ego develops in order to mediate between the unrealistic id and the external real world (like a referee). It is the decision making component of personality
The ego operates according to the reality principle, working our realistic ways of satisfying the id’s demands, often compromising or postponing satisfaction to avoid negative consequences of society. The ego considers social realities and norms, etiquette and rules in deciding how to behave.
The superego incorporates the values and morals of society which are learned from one's parents and others. It is similar to a conscience, which can punish the ego through causing feelings of guilt.
Trait Approach to Personality
This approach assumes behavior is determined by relatively stable traits which are the fundamental units of one’s personality. Traits predispose one to act in a certain way, regardless of the situation. This means that traits should remain consistent across situations and over time, but may vary between individuals.
It is presumed that individuals differ in their traits due to genetic differences.
These theories are sometimes referred to a psychometric theories, because of their emphasis on measuring personality by using psychometric tests.
Eysenck’s Personality Theory
Eysenck (1952, 1967, 1982) developed a very influential model of personality. Based on the results of factor analyses of responses on personality questionnaires he identified three dimensions of personality: extraversion, neuroticism and psychoticism.
During 1940s Eysenck was working at the Maudsley psychiatric hospital in London. His job was to make an initial assessment of each patient before their mental disorder was diagnosed by a psychiatrist. Through this position he compiled a battery of questions about behavior, which he later applied to 700 soldiers who were being treated for neurotic disorders at the hospital (Eysenck (1947).
He found that the soldiers's answers seemed to link naturally with one another, suggesting that there were a number of different personality traits which were being revealed by the soldier's answers. He called these first order personality traits
He used a technique called factor analysis. This technique reduces behavior to a number of factors which can be grouped together under separate headings, called dimensions.
Eysenck (1947) found that their behavior could be represented by two dimensions: Introversion / Extroversion (E); Neuroticism / Stability (N). Eysenck called these second-order personality traits.
According to Eysenck, the two dimensions of neuroticism (stable vs. unstable) and introversion-extroversion combine to form a variety of personality characteristics.
Extraverts are sociable and crave excitement and change, and thus can become bored easily. They tend to be carefree, optimistic and impulsive.
Introverts are reserved, plan their actions and control their emotions. They tend to be serious, reliable and pessimistic.
Neurotics / unstables tend to be anxious, worrying and moody. They are overly emotional and find it difficult to calm down once upset.
Stables are emotionally calm, unreactive and unworried.
Eysenck (1966) later added a third trait / dimension - Psychoticism – e.g. lacking in empathy, cruel, a loner, aggressive and troublesome.
Eysenck related the personality of an individual to the functioning of the autonomic nervous system (ANS). Personality is dependent on the balance between excitation and inhibition process of the nervous system. Neurotic individuals have an ANS that responds quickly to stress.
Cattell's 16PF Trait Theory
Cattell (1965) disagreed with Eysenck’s view that personality can be understood by looking at only two or three dimensions of behavior.
Instead, he argued that that is was necessary to look at a much larger number of traits in order to get a complete picture of someone’s personality.
Whereas Eysenck based his theory based on the responses of hospitalized servicemen, Cattell collected data from a range of people through three different sources of data.
- L-data - this is life record data such as school grades, absence from work etc.
- Q-data - this was a questionnaire designed to rate an individual's personality.
- T-data - this is data from objective tests designed to 'tap' into a personality construct.
Cattell analyzed the T-data and Q-data using a mathematical technique called factor analysis to look at which types of behavior tended to be grouped together in the same people. He identified 16 personality traits / factors common to all people.
Cattell made a distinction between source and surface traits. Surface traits are very obvious and can be easily identified by other people, whereas source traits are less visible to other people and appear to underlie several different aspects of behavior. Cattell regarded source traits are more important in describing personality than surface traits.
Allport's Trait Theory
Allport's theory of personality emphasizes the uniqueness of the individual and the internal cognitive and motivational processes that influence behavior. For example, intelligence, temperament, habits, skills, attitudes, and traits.
Allport (1937) believes that personality is biologically determined at birth, and shaped by a person's environmental experience.
Critical Evaluation of Trait Theories
Twin studies can be used to see if personality is genetic. However, the findings are conflicting and non-conclusive.
Shields (1976) found that monozygotic (identical) twins were significantly more alike on the Introvert – Extrovert (E) and Psychoticism (P) dimensions than dizygotic (non-identical) twins.
Loehlin, Willerman and Horn (1988) found that only 50% of the variations of scores on personality dimensions are due to inherited traits. This suggests that social factors are also important.
Adorno et al. (1950) proposed that prejudice is the results of an individual’s personality type.