1916 - 1997

Eysenck defined personality as a more or less stable and enduring organization of a person’s character, temperament, intellect, and physique, which determines his unique adjustment to the environment.

His definition emphasized traits (stable and enduring characteristics), which, when clustered together, are organized as types.

Eysenck’s typology is hierarchically organized, and consists of types, traits, and habits.

On the basis of numerous factor analysis of personality data gathered from different subject populations all over the world, Eysenck derived two types that could readily be labeled: introversion/extraversion and stability/neuroticism.

Later, on the basis of other statistical analyses, he postulated a third type, impulse control/psychoticism.

Extraverts are sociable and impulse individuals who like excitements and who are oriented toward external reality.

Introverts are quiet, introspective individuals who are oriented toward inner reality and who prefer a well-oriented life.

Neurotics, in Eysenck’s view, are emotionally unstable individuals. Some unreasonably fear certain objects, places, persons, animals, open spaces, or heights; others exhibit obsessional or impulsive symptoms.

The hallmark of the disorder for most neurotics is an anxiety level disproportionate to the realities of the situation.

Some neurotics are free from anxiety and fear.

In this grouping we find the psychopaths - individuals who seem unable to assess the consequences of their actions and who behave in an asocial or antisocial manner regardless of the punishment meted out by others.

Psychotics differ from neurotics. Showing the most severe type of

psychopathology, psychotics are insensitive to others, hostile, cruel, and inhumane, with a strong need to make fools of people and to upset them.

Despite these socially undesirable traits, psychotics tend to be creative.

The traits associated with psychoticism are conducive to the pursuit of a creative career.

Geniuses must buck tradition to strike out on their own.

The hallmark of the creative genius is her or his ability to think in unusual, almost bizarre ways.

If psychotics and geniuses share the trait of creativity, why do geniuses produce outstanding works that contribute to society, whereas most psychotics spend their lives in institutions and fail to achieve greatness?

We have to consider combinations of personality traits.

Geniuses are generally characterized by high ego strength and confidence, extraordinarily high persistence, motivation, and very high intelligence.

These same qualities do not characterize psychotics.

Eysenck maintained that extraverts have relatively strong inhibitory processes and weak excitatory processes.

Their strong nervous systems mean they have a large capacity to tolerate stimulation.

Introverts, in contrast, have strong excitatory processes and weak inhibitory processes.

Their weak nervous systems mean they have only a small capacity to tolerate stimulation.

Thus, the brains of extraverts react more slowly and weakly to stimuli, thereby creating a stimulus hunger, or desire for strong sensory stimulation, which causes them to seek excitement by approaching the environment, attending parties, making friends, taking risks, and so forth.

Introverts are inherently more cortically aroused, have brains that react more quickly and strongly to stimuli, and can tolerate only relatively small amounts of stimulation.

As a result, they spend more time in contemplative activities such as reading, writing, and playing chess.

This inhibition theory, leads to a host of behavioral predictions that have generally been empirically confirmed.

For example, in comparison to introverts, extraverts are fonder of loud music, bright colors, and jazz (unusual, and therefore more interesting and stimulating).

Extraverts are more likely to use alcohol and other drugs, to smoke, and to engage in various types of sexual activity.

Compared to introverts, extraverts have sexual intercourse at an earlier age, more frequently, with more partners, and in a wider range of positions.

Reactive inhibition - a neural fatigue that builds to the point where the individual can no longer respond.

Eysenck maintained that extraverts are more susceptible to reactive inhibition than introverts and, as a result, are more likely to tire of a given activity sooner and turn to another.

They thus tend to change jobs or careers more frequently, are more likely to change boyfriends or girlfriends and to get divorced.

According to Eysenck, socialized conduct is mediated by conscience, which he defines as the sum total of an individual’s learned or conditioned responses.

Individuals learn behaviors that run counter to their own wishes to avoid being punished by authority figures.

Thus, through conditioning, individuals learn to desist from performing behaviors that society deems harmful.

Society also rewards individuals for exhibiting certain behaviors, and thereby shapes their behavior in ways that society considers acceptable.

Eysenck proposed that introverts learn the rules more quickly and efficiently than extraverts.

He believes that the basis for these differences is genetic: Introverts have chronically higher cortical arousal; arousal tends to facilitate learning; therefore, introverts learn more readily than extraverts.

Because it is more difficult for extraverts to learn societal rules, they tend to be undersocialized, whereas extreme introverts tend to be oversocialized.

Extraverts are less mature generally than introverts.

For extraverts to learn the appropriate behaviors, it takes many more instances of pairing the lying - or stealing or other behavior - with punishment before the lessons are learned.

Psychoticism and intelligence level have also been linked to antisocial and criminal behavior.

Criminals tend to have lower IQs according to Eysenck.

Eysenck was most emphatic in pointing out that personality development can and does respond to socialization.

Predispositions for a person to behave in a certain manner are genetically determined, but these response tendencies can be modified by environmental influences.

In Eysenck’s view, neurotic behavior is most likely to be learned under certain environmental conditions.

The acquisition of disordered behavior by such individuals obeys the laws of learning, and these same conditioning principles can be used to eliminate the undesirable behaviors and to teach new, desirable ones.

Eysenck called the application of learning theory and principles to the treatment of disordered behavior behavior therapy.

Eysenck advocated three major behavior techniques that have been used successfully to treat a variety of phobias - enuresis, obsessions, compulsions, test anxiety, and public speaking anxiety.

These three techniques are modeling, flooding, and systematic desensitization.

In modeling, phobic people watch nonphobics cope successfully with dreaded objects or situations.

In flooding, clients are exposed to dreaded objects or situations for prolonged periods of time in order to extinguish their fear.

Systematic desensitization involves a gradual, client-controlled exposure to the anxiety-eliciting object or situation.

Systematic desensitization involves counterconditioning by having the client make a response antagonistic to anxiety in the presence of the anxiety-evoking stimuli, so that anxiety is suppressed.