Hans Eysenck's Three-Factor Model Notes

The Big Five vs Hans Eysenck's Three-Factor Model

• The Big Five (five-factor model) is described as the main or overarching approach to traits.
• In crime research, the dominant figure discussed is Hans Eysenck, who developed a three-factor model.
• The three factors are:
  • Extraversion
  • Neuroticism
  • Psychoticism
• Relationship to the Big Five:
  • Extraversion and Neuroticism align closely with the Big Five components.
  • Psychoticism is roughly a blend of Agreeableness and Conscientiousness from the Big Five; Openness is not represented in the three-factor model.
• Structure of the model (the ‘super trait’ idea):
  • Psychoticism is the larger trait, under which sit related primary traits (or trays).
  • Examples of primary trays under Psychoticism include:
  • Impulsivity
  • Empathy
  • These trays can be viewed separately or grouped under Psychoticism.
  • Under Extraversion, related traits include:
  • Sensation seeking is positioned under Extraversion along with other related attributes.
  • Under Neuroticism, related traits include:
  • Anxiousness
  • Depression
  • Guilt feelings
  • Low self-esteem
  • Other related behaviours
• The three-factor model’s strength is that Eysenck explicitly tried to develop the biological foundations of these trays and link them to prior topics in the course.

Biological Foundations and the Three Dimensions

• Psychoticism (the larger trait) and its biology:
  • Associated with a lack of empathy and with “tough-minded”, potentially aggressive individuals.
  • Biologic underpinnings: high levels of testosterone and low levels of serotonin are suggested as contributing factors.
  • Note: the transcript uses the term “Coticism” which appears to be a misspelling of Psychoticism.
• Extraversion:
  • Traits: liveness, sensation seeking, sociability.
  • High Extraversion individuals seek a lot of external stimulation.
  • This tendency is assumed to be underpinned by sub-optimal arousal (under arousal).
• Neuroticism:
  • Traits: emotional instability, anxiety, moodiness.
  • High Neuroticism: more easily provoked, less likely to weigh up consequences.
  • Linked to the autonomic nervous system and the fight-or-flight responses discussed in an earlier lecture.
• Orthogonality (independence) of the three dimensions:
  • The three dimensions are orthogonal, meaning they are independent and do not correlate with each other.
  • This independence is represented visually as three-dimensional axes.
• Three-dimensional representation:
  • A 3D space with the following axes:
  • X axis: Introversion – Extraversion
  • Y axis: Emotional stability – Emotional instability
  • The Psychoticism trait extends outward from the page, creating a 3D configuration
  • This setup yields eight different possible permutations of high/low levels across the three traits.
  • The eight permutations arise from combining high or low levels on each of the three dimensions.
• Notation of highs and lows:
  • The transcript indicates that uppercase designations represent high levels, and lowercase indicate low levels.
  • Example: a profile could be High Psychoticism (P), High Extraversion (E), High Neuroticism (N) or any combination thereof.
• The eight possible permutations (illustrative):
  • High P, High E, High N
  • High P, High E, Low N
  • High P, Low E, High N
  • High P, Low E, Low N
  • Low P, High E, High N
  • Low P, High E, Low N
  • Low P, Low E, High N
  • Low P, Low E, Low N
  • Note: these permutations yield different personality clusters or profiles within the three-factor framework.

Core Takeaways and Implications

• The three-factor model offers a biologically inspired alternative to the Big Five, with clear mappings to behavior relevant to crime research.
• Openness is not captured by Eysenck’s three-factor model, which is a key divergence from the Big Five.
• The model emphasizes a biologically grounded explanation for personality traits and their interrelationships, but it remains controversial in criminological research.
• The orthogonality claim implies that interventions or assessments targeting one dimension should not assume automatic changes in the others, due to independence.
• The eight-trait permutation framework provides a practical way to categorize individuals into distinct personality clusters for research and potential prediction, while acknowledging that real-world personality may be more nuanced.

Connections to Earlier Topics and Real-World Relevance

• Links to prior discussions on arousal theory (underarousal as a driver for Extraversion-related behaviors).
• Autonomic nervous system involvement aligns with earlier lectures on physiological bases of emotion and behavior.
• The climate of controversy around “psychoticism” as a trait in criminology, balancing predictive utility with concerns about labeling and interpretive risks.

Important Observations and Caveats

• The transcript emphasizes that Psychoticism is not simply Agreeableness or Conscientiousness but a composite construct with distinct implications for behavior.
• The absence of Openness highlights a limitation of collapsing Big Five dimensions into a three-factor model.
• While the biological associations are presented, these are theoretical links that have been debated and refined in subsequent research.
• The idea of eight trait permutations is a simplification; real-world personality spectra are continuous and multidimensional beyond a simple high/low dichotomy.

$8$ possible permutations of high/low across the three factors illustrate the combinatorial space of Eysenck’s model.

Quick Reference: Key Terms

• Extraversion (E)
• Neuroticism (N)
• Psychoticism (P)
• Orthogonal dimensions
• Underarousal (sub-optimal arousal) concept for Extraversion
• Autonomic nervous system (fight/flight) linkage for Neuroticism
• Testosterone and serotonin (5-HT) as proposed biological factors for Psychoticism
• Big Five (Five-Factor Model): Openness, Agreeableness, Conscientiousness, Extraversion, Neuroticism