1. Psychobiological & lexical approaches to personality: Enter the matrix Dr Niko Tiliopoulos Room 448, Brennan McCallum building Email: nikot@psych.usyd.edu.au

2. Assumptions of the Traits approach I Personality exists! Personality exists! Personality is a probabilistic and dynamic system Personality is a probabilistic and dynamic system Personality has both quantity and quality properties Personality has both quantity and quality properties Systematically describes differences between (and within) individuals Systematically describes differences between (and within) individuals Emphasises the need of a useful scientific taxonomy Emphasises the need of a useful scientific taxonomy Personality is the dynamic & organised set of characteristics possessed by a person that uniquely influences her or his cognitions, motivations, attitudes, behaviour, and psychology as a whole

3. Assumptions of the Traits approach II Personality develops through the interplay between: –Cognition (memory, perception, thought, language, intelligence) –Temperament (characteristic reaction patterns, present from an early age) –Constitution or physiology (neurology, endocrinology, genetics, etc.) –Environment (both human and physical)

4. The Personality pie (an evidence-based representation) Non-shared environment Shared environment 50% 10% 40% Biologygenetics Unique experiences Diseases Accidents Diet Lifestyle Aspirations/Motives Religiosity/Spirituality Choices Chance! Unique experiences Diseases Accidents Diet Lifestyle Aspirations/Motives Religiosity/Spirituality Choices Chance! Family Socialisation Schooling Culture Religion Evolution Family Socialisation Schooling Culture Religion Evolution Neurotransmitters Brain systems Hormones Nervous system Age Sex Genes Evolution Neurotransmitters Brain systems Hormones Nervous system Age Sex Genes Evolution

5. Assumptions of the Traits approach III The building blocks of personality are called Traits Traits are “general dispositions that people possess that uniquely influence their psychology” –E.g. outgoing, impulsive, anxious, sociable, hostile, optimistic, altruistic Every human possesses ALL traits, but not at the same intensity (or centrality) Their development is assumed to end in early adulthood They are relatively stable over time and situation –Traits vs. States Personality is dimensionally and hierarchically arranged

6. The hierarchical arrangement of personality More stable Simpler Complex Less stable Fewer dimensions (higher level of dimensionality) More dimensions (lower level of dimensionality) 1. Stability 2. Complexity 3. Dimensionality 1. Stability 2. Complexity 3. Dimensionality

7. Situation ← Tendency to socialise or act on impulse ← Group-activities, leader, extreme sports, careless, promiscuous ← Differential cortical & dopaminergic activation

8. How does the Traits approach discover personality? (Common) assumptions: –The personality space is made up of dimensions –These dimensions tend to be independent from each other –These dimensions are finite –We can discover these dimensions by decomposing the personality matrix! Statistics –Factor analysis

9. Two main traits typologies The Lexical taxonomy (the Big-5) (seeks to identify trait-descriptors in natural language) –Neuroticism: Emotional stability –Extraversion: Having a social impact –Agreeableness: Maintaining positive relations with others –Conscientiousness: Responsibility and will to achieve –Openness: Artistic tendencies, intellect, being open to new ideas or change The Psychobiological taxonomy (the Big-3) (seeks to identify the biological/genetic markers of traits) –Neuroticism (related temperament: emotionality) A predisposition to mood and anxiety disorders –Extraversion (sociability and impulsivity) A predisposition to accidents and injuries It mediates the psychopathological effects of the other two dimensions –Psychoticism (tough- vs. tender-mindedness) A predisposition to psychotic disorders

10. Contributions Scientific theories that are evidence-based Clear-cut predictions Testable Cross-cultural validity Occupational/educational psychology Psychopathology (the foundation of Clinical Psychology) Evolutionary (personality) psychology & Animal psychology Forensic psychology & criminal profiling

11. Criticism How many traits or dimensions? Heavily dependent on statistics Heavily dependent on self-reports When assessment is based on medical methods it is impractical Actually, do traits exist at all?

12. Some famous individuals that exemplify trait characteristics Trait description Famous individual HighLowHighLow Assertive, dominant Humble, cooperative Genghin Khan Jesus Conscientious, persistent Expedient, undisciplined Mother Teresa Casanova Tense, driven Relaxed, tranquil MacbethBuddha Tough-minded, self-reliant Tender-minded, sensitive James Bond Robert Burns Self-sufficient, resourceful Group-dependent, affiliative Copernicus Marilyn Monroe Controlled, compulsive Undisciplined, lax Margaret Thatcher Mick Jagger Venturesome, socially bold Shy, retiring Columbus Sylvia Plath

13. Main traits theorists Gordon Allport (1897 - 1967) Raymond Cattell (1905 - 1998) Hans Eysenck (1916 - 1997) Jeffrey Alan Gray (1934 - 2004) Marvin Zuckerman (1928 - ) Kim Bartholomew (?) Claude Robert Cloninger (1944 - ) Theodore Millon (1928 - ) Cindy Hazan (?) David Buss (1953 - ) Samuel Gosling (?)