Eysenck's Trait Model and the Big Five Personality Factors

Introduction to Trait Theory

A trait is a unit of analysis used to describe, explain, and predict human thought and behavior (Lecci, 2015). Traits are the building blocks of personality. The earliest contributors to the trait personality model include Hippocrates and Galen, Carl Jung, and Gordon Allport. This paper traces the development of personality theory with specific reference to Eysenck's three-factor model. It also discusses the five personality dimensions of the Big Five model and uses self-assessment results to evaluate personality.

Eysenck's Three-Factor Theory

Personality models are among the earliest forms of psychological theory. Throughout history, personality theories have evolved as theorists attempt to build the most plausible foundations for understanding an individual's personality. The earliest documented works related personality to internal balances within the humors system and the central nervous system, both of which limited quantitative measurement (Lecci, 2015).

Hans Eysenck was among the greatest contributors to the field of personality psychology. He believed that biological factors underlie all human traits (Allemand, Steiger, & Hill, 2013). As such, all individuals inherit a type of nervous system that influences how they learn and adapt to their environment. Eysenck viewed people as having three personality dimensions: introversion vs. extraversion, stability vs. neuroticism, and socialization vs. psychoticism (Kussner, 2017; Lecci, 2015). Each aspect of personality can be traced to a different biological cause. For instance, Eysenck believed that extraversion was caused by differences in cortical arousal, with introverts having a lower activity level than extraverts in this area. Neuroticism, on the other hand, was attributed to differences in the limbic system — the part of the brain involved in motivation, emotion, and emotional association with memory.

Eysenck posited that an individual's personality is influenced by the balance between inhibition and excitation processes of the autonomic nervous system (Kussner, 2017). According to the theory, extraverted people are outgoing, sociable, and readily connect with others, while introverts have a higher need to be alone and to engage in solitary behavior (Lecci, 2015). In the stability/neuroticism dimension, people high on neuroticism are anxious and tend to enter a fight-or-flight reaction even under low levels of stress, while those high on stability are more emotionally stable. In the socialization/psychoticism dimension, people high on socialization have strong impulse control and are more cooperative and altruistic, while those high on psychoticism are more antisocial, impulsive, cold, and independent in their thinking. Eysenck's theory was an improvement on earlier personality trait approaches because it was more quantifiable — psychological theories have long been criticized for not being empirically verifiable (McCrae, 2011). However, the theory has since been superseded by newer frameworks such as the Five-Factor Model (McCrae, 2011).

Differences Between Eysenck's Theory and Psychodynamic Theory

Eysenck's theory of personality shares some similarities with Sigmund Freud's psychodynamic theory. The psychodynamic theory assumes that there is an interaction between innate instincts (nature) and parental influences (nurture). Both models theorize a high-level mental mechanism that either requires the satisfaction of sexual desires (Freud) or the stimulation of arousal needs (Eysenck). The psychodynamic model is founded on the sexual desire principle, which is innate and demands instant gratification (Nettle, 2009). Accordingly, the individual under the psychodynamic model is driven by unconscious processes influenced by sex, aggression, and childhood experiences. Conversely, Eysenck argued that personality is driven by brain arousal needs, which lead to extraversion or introversion, stability or neuroticism, and socialization or psychoticism (Nettle, 2009).

Another difference between the two theories concerns the measurability of variables. Eysenck used statistical methods to support the existence of personality factors, while Freud's psychodynamic theory emphasizes the idea of the human unconscious, which is not empirically testable (Nettle, 2009). A third difference involves the mode of acquiring personality: Eysenck argued that an individual's personality is present at birth and does not fundamentally change over their lifetime. The psychodynamic theory, by contrast, holds that personality is acquired through childhood experiences, particularly parental influence. In Freud's view, personality develops through the interplay of one's environment and instincts during the formative years of life (Nettle, 2009). Parental behavior is therefore crucial for a child's development, and mental health or personality problems in adulthood may be traced to the first five years of life. Despite their differences, both theories share a common weakness: neither adequately explains possible changes in an individual's personality over time.

The establishment of the Big Five model of personality represented a major turning point in the history of personality psychology (McCrae, 2011). The Big Five model is the observation that all personality traits are aspects of one or more of five fundamental factors: neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness (McCrae, 2011).

The Big Five Model

Conclusion

This paper summarizes the concepts and assumptions of Freud's psychodynamic theory and Eysenck's personality theory. The fundamental differences between the two models lie in the inheritability of personality traits and the causes of personality differences. Eysenck assumes that personality is driven by brain arousal needs, while the psychodynamic theory argues that personality is driven by unconscious processes. Furthermore, Eysenck assumes that personality is innate, while Freud's psychodynamic theory holds that personality is shaped during early childhood, particularly through parental influence. The Big Five personality self-assessment revealed high scores in conscientiousness and agreeableness, a moderate score on openness to experience, and low scores on both neuroticism and extraversion.