Understanding Personality

What is Personality?

• Personality comes the latin word 'persona'
• 'Persona' refers to the mask one wears to portray a character, or the role/character one plays in life's drama.
• Funder (1997) defined personality as an individual’s characteristic pattern of thought, emotion, and behavior, together with the psychological mechanisms (hidden or not) behind those patterns.
• Carver & Scheier (2000) described it as a dynamic organisation inside the person of psychophysiological systems that create a person's characteristic patterns of behavior, thoughts, and feelings.
• Wilt & Revelle (2014) defined it as abstractions that explain patterns of affect, behavior, cognition, and sometimes desires.

Overarching Approaches to Personality

• Nomothetic approach suggests that individual differences can be described and explained in terms of predefined attributes applicable to everyone.
• Idiographic approach suggests individuals are so unique that two different people cannot be described using the same concepts, like in Freud’s psychodynamic theory.
• Dispositional approach views personality as consistent, internal dispositions to think, act, and feel in similar ways, largely independent of the situation; relates to the nomothetic approach.
• Situational approach considers personality as a series of largely unrelated states, primarily determined by situational factors, with no core essence, but distinct behavioural signatures made of 'if A then B' rules.
• Dispositional theorists do not deny a role of context/situation in moderating behaviour.
• There is a significant correlation between traits and behaviour (estimates of r = 0.40 (Funder, 2001)) with traits also influencing the types of situations encountered.

Early Models of Personality: The Four Temperaments

• Early personality theory originated in ancient Greece philosophy, rooted in descriptions of physical and mental disturbance.
• Hippocrates (460-377 BC) described physical illnesses as arising from the balance of bodily fluids ('humours').
• Galen (AD 130-200) applied this theory to describe temperament.
• The four temperaments relate to a balance of bodily fluids, and includes:
  • Sanguine
  • Melancholic
  • Choleric
  • Phlegmatic
• Early models contribute to the notion of personality 'types', temperament descriptors have influenced modern personality theories, and specifies links between biology and temperament.

Biological Approaches: Eysenck's PEN theory

• Eysenck's initial theory (1947) Two dimensions of personality: Extraversion and Neuroticism

• Dimensions are orthogonal to one another (independent).

• Assumes a normal distribution for each dimension.

• The theory considers 'super traits' that provide complete description, with a biological underpinning.

• Higher neuroticism refers to a person's level of emotionality and tendency to worry.

• Eysenck was inspired by Galen’s four temperament model and created a model where:

  • Low extraversion is between melancholic and phlegmatic
  • Higher neuroticism is between melancholic & choleric
  • Low neuroticism is between phlegmatic & sanguine
  • High extraversion is between sanguine & choleric

• In the 1970s Eysenck observed individuals who were emotionally unstable (N) but with lower levels of fear and anxiety, lack of remorse/conscience, or appreciation of consequences, calling them “psychopaths”.

• Eysenck and Eysenck added “Psychoticism” dimension to the model.

• The 'Psychoticism' dimension is not normally distributed, and is not independent of N (some positive correlation).

• Psychoticism is a major trait in Eysenck's PEN model of personality, and is almost certainly misnamed (Lilienfeld et al., 2015). Described as perhaps better labelled as 'psychopathy'.

• Reticulo-cortical system explains extraversion and introversion explained by differential activity.

• Moderate levels of cortical arousal are preferred; Extraverts have lower levels and seek external stimulation, introverts have higher levels and avoid external stimulation.

• Hypothesis is that, in a given situation, extraverts will have lower levels of cortical arousal than introverts.

• Tran, Craig & McIsaac (2001) researched and addressed some methodological issues like:

  • Activity measured from frontal regions of the brain.
  • Older participants (22-60 years, mean age=38.3 years).
  • Used 'moderately demanding' task (opening and closing eyes)
  • Compared mean amplitude of EEG activity between extraverts and introverts.

• In this study it was found that there was a significant difference: The size of the waves was higher in extroverts whereas introverts was lower in amplitude The reticulo-limbic system explains Neuroticism-Stability based on the differential activity levels.

• Eysenck proposed that neuroticism results from greater arousal in the reticulo-limbic system and psychoticism is linked to male hormones or dopamine levels.

• Good (cross-cultural) evidence for E and N factors.

• Major contribution to trait and biological theories of personality

• Development of several personality questionnaires, including:

  • EPI (Eysenck Personality Inventory)
  • MMQ (Maudsley Medical Questionnaire)
  • EPQ-R (Eysenck Personality Questionnaire (revised))
  • EPP (Eysenck Personality Profiler)

• P factor is less accepted and is not featured in other models.

• The Neurobiology of emotional processing is more complex than originally thought.

• Too much focus on biology/genetics...?

Biological Approaches: Gray BAS/BIS (Reinforcement Sensitivity) Theory

• Jeffrey Gray (1934-2004) developed an alternative to Eysenck’s theory based on work with non-human animals and applied to all mammals.
• Assumes that Individual differences lie in strengths of BAS and BIS.
• Behavioural Activation System (BAS) activates 'approach' behaviour toward a goal, motivates to seek reward, and is based on conditioned responses associated with positive events.
• Behavioural Inhibition System (BIS) focuses attention on potential costs, inhibits behaviors associated with negative events, and motivates to avoid harm and punishment.
• BAS related to High impulsivity and High E (extraversion).
• BIS related to High anxiety and Low E (introversion).
• There is a newer revised theory in line with advances in neuroscience (r-RST).
• Walker et al. (2017) developed an additional ‘Fight/Flight/Freezing System' (FFFS) as well as BIS as an evaluative comparator of response conflicts.