The three dimensions of Hans Eysenck’s personality

Son of famous parents, Hans Eysenck was one of the most controversial and prolific psychologists of the 20th century. At the time of his death in 1997, he was the most cited researcher in psychology. He thus made a significant contribution to this field, publishing around 80 books and writing hundreds of articles. He was also the founding editor of the influential magazine Personality and Individual Differences.

He was born in Germany in 1916 but, in 1934, he was forced to emigrate from his country due to his opposition to the Nazi party. He took refuge in France until 1939 and later in Great Britain, where he completed his doctorate in psychology at the University of London in 1940.

During World War II, Hans Eysenck worked at the Mill Hill emergency hospital as a psychiatrist. Between 1945 and 1950 he was a psychologist at Maudsley Hospital. He later became head of the psychology department at the Institute of Psychiatry, University of London, a position he held until 1983.

Hans Eysenck developed a very influential theory of personality, based on biological factors; arguing that individuals inherit a type of nervous system that affects their ability to learn and adapt to the environment. However, her work drew criticism for suggesting that biological or genetic factors influence an individual’s personality and susceptibility to engaging in criminal behavior.

Dimensions of Hans Eysenck’s personality: the PEN model

In Eysenck’s personality theory, a person’s behavior can be organized into four different levels. Namely:

First level: Specific answers. They are responses that occur only once, in a particular situation and that do not in themselves determine the personality of the subject.Second level: Common responses. They are those that are frequently carried out in similar situations, and that resemble a personality style.Third level: Traits. Habitual responses will give rise to a personality trait. These traits are, for example, sociability, impulsivity, kindness, liveliness, etc.Fourth level: Dimensions. This is a more general level, which includes the grouping of traits, which is why it determines the individual’s way of being. According to Eysenck, personality is composed of three dimensions: Extraversion, Neuroticism and Psychoticism; which have their opposite: Introversion, Emotional Stability and Self-control, respectively.

Let’s see in detail the characteristics of these three dimensions.

Extraversion – Introversion

People with high levels of extraversion participate more in social activities. They tend to be more communicative and feel more comfortable in groups. In general, extraverts enjoy being the focus of attention and often accumulate a larger social network of friends and associates. Extraversion is measured on a continuum, ranging from high (extraverted) to low (introverted).

For its part, Introverts tend to be quieter, shy away from large social gatherings, and may feel uncomfortable interacting with strangers. Instead, they maintain smaller groups of close friends and are more likely to enjoy contemplative exercises.

The Swiss psychoanalyst Carl Jung suggested that levels of extraversion-introversion depend on the focus of an individual’s psychic energy. In extraverts, he believed this energy was directed outward toward other people, resulting in more social interactions. Meanwhile, introverts’ psychic energy is projected inward, leading them to engage in less sociable, internally focused activities.

However, Eysenck believes that extraversion is related to levels of brain activity or cortical arousal. Extraverts experience lower levels of cortical arousal, leading them to seek arousal from external stimuli. Higher arousal levels in introverts lead them to avoid stimuli that can lead to greater increases in arousal.

Neuroticism – Emotional Stability

On the other hand, People who score high on measures of neuroticism would tend to experience higher levels of stress and anxiety. They tend to worry about relatively insignificant matters, exaggerating their significance and feeling unable to cope with stressors.

Instead, a A person with a low neuroticism score will generally experience greater emotional stability. We are talking about people who, in general, feel more capable of coping with stressful events and setting goals that are more in line with their abilities.

Additionally, people low in neuroticism tend to be more tolerant of the faults of others and remain calmer in demanding situations.

Like extraversion, Eysenck offers a biological explanation for neuroticism. In this case, he refers to the activation of the sympathetic nervous system or visceral brain; in which structures such as the hippocampus, amygdala, septum and hypothalamus intervene. Now, these regulate emotional states such as fear and aggression, and are responsible for the fight or flight response to danger.

Having said that, People with high levels of neuroticism have low thresholds for visceral brain activation and are unable to inhibit or control their emotional reactions. Consequently, they experience negative effects in stressful situations; they get upset in moments of tension; and they get angry more easily than those who have high levels of emotional stability.

Psychoticism – Normality

Psychoticism was a late addition to Hans Eysenck’s theory of personality, and was included in 1976. This third dimension of personality ranges from normality (low psychoticism) to high psychoticism.

People with higher psychoticism scores are more likely to engage in irresponsible or misjudged behavior. They may also contravene accepted social norms and be motivated by a need for immediate gratification, regardless of its consequences.

However, psychoticism also has more positive associations. In a 1993 study, Hans Eysenck compared participants’ scores on the Barron-Welsh Art Scale and the Eysenck Personality Questionnaire and found that People scoring high on psychoticism tended to possess more advanced creative abilities.

Eysenck also suggested that psychoticism was influenced by biological factors and correlated with levels of hormones such as testosterone and enzymes such as monoamine oxidase (MAO). In this sense, it has been found that People who have psychotic episodes have high levels of testosterone and low levels of MAO.

For its part, According to the PEN model, high levels of psychoticism reduce a person’s responsiveness to conditioning, which means that it would have a harder time adapting to the social norms that we usually learn through reward and punishment.

As a result, the theory suggests that people may be more prone to criminal behavior to the extent that they seek to satisfy their own interests, while violating the rules of behavior accepted by others.

The association of personality traits, such as psychoticism, with criminal tendencies, along with Eysenck’s emphasis on genetics affecting such traits, has led some to criticize his theory for taking a deterministic view of behavior.

Criticisms of Hans Eysenck’s theory

Twin studies can be used to see if personality is genetic. However, the findings are contradictory and inconclusive. For example, monozygotic (identical) twins were found to be significantly more similar on the Introverted – Extroverted and Psychotic dimensions than dizygotic (non-identical) twins.

However, Loehlin, Willerman, and Horn (1988) found that only 50% of the variation in scores on personality dimensions is due to inherited traits. This suggests that social factors are also important.

A virtue of Eysenck’s theory is that it considers both nature and nurture as influencing factors. It maintains that biological predispositions towards certain personality traits, combined with conditioning and socialization during childhood, condition our personality.

This interactionist approach can therefore accumulate greater validity than a pure biological or environmental theory. It also ties in nicely with the diathetic stress model of behavior, which argues for a biological predisposition that combines with an environmental trigger for a particular behavior.

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