This summary includes the Personality traits Lecture, it's a recorded lecture. The lecture covered Chapter 10, 11, 12, and only pages 429 – 448 (without the boxes on pages 437- 439, and 444 - 445), and pages 461 - 467 of chapter 18 The Individual Book (de Bruin, E., 1st Edition)

DISPOSITIONAL TRAITS

Personality Psychology:

• The scientific study of the whole person
  • focusing on individual similarities and differences
  • in biological and social-cultural context

MCADAMS & PALS (2006)

• Dispositional traits --> Sketch a behavioural outline
• Characteristic adaptations --> Fill in details of human individuality
• Integrative life narratives --> Tell what a person’s life means
• Biological context --> Heritability and physiology
  
  • William Utermohlen:
    
    • Painter with Alzheimer --> kept on painting self-portraits --> they increasingly fade out (lose of personality + cognitive abilities to paint)
• Cultural context --> Socio-cultural processes
  
  • Primo Levi --> Auschwitz camp survival --> Writes a book on ‘How is it possible to survive there?’ --> killed himself
    
    • He felt as his personality was taken away from him (shaving head, …) --> “the only way someone can survive that environment is by keeping their personality alive”

DISPOSITIONAL TRAITS

APPROACHES

• Hippocrates (460-370 BC): Medicine
  • Four ‘humors’ or bodily fluids: Blood, yellow bile, black bile, phlegm
• Galenus (130-200 AD): 4 temperaments
  
  • Sanguine, choleric, melancholic, phlegmatic
• Personality types: A set of dispositions within the individual that are organized and relatively enduring and that influence his or her interactions with and adaptations to the environment
  
  • Enneagram: a model of the human psyche which is principally understood and taught as a typology of nine interconnected personality types.
  • Myers-Briggs Type Indicator: a self-help assessment test which helps people gain insights about how they work and learn.
  • The Big Five: Almost unlimited combinations across dimensions of personality

TAXONOMIES

HOW CAN WE IDENTIFY TRAITS?

• Theoretical approach (Eysenck): Define number and content of traits top-down 
• Lexical approach (Cattell, Wiggins, Goldberg, Costa & McCrae, Hexaco)
  
  • Assess natural language bottom-up
  • Synonyms and cross-cultural universality
• Statistical approach: used in all Taxonomies
  
  • Develop tests
  • Assess psychometric properties (factor analysis, CTT, and IRT analysis)

WHICH TRAITS DO EXIST?

• Eysenck: Extraversion, Neuroticism, Psychoticism
• Cattell: 16 factors, like Warmth, Impulsivity, Dominance etc.
• Goldberg Big Five: Intellect, Conscientiousness, Surgency, Agreeableness, Neuroticism
• Costa & McCrae Big Five: Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism
• Hexaco model: Humility-Honesty, Emotionality, extraversion, Agreeableness, Conscientiousness, Openness to experience

HOW ARE TRAITS ORGANIZED?

Megatraits (DeYoung):

• Stability: Agreeableness, Conscientiousness, low Neuroticism
  • The tendency to resist being distracted from pursuing your long-term goals by immediate interruptions such as emotions and doubts
• Plasticity: Extraversion, Openness to Experience
  
  • The tendency to generate and attend to new experiences by generating new strategies to pursue new goals and responding more eagerly to unusual experiences

MEASURMENT:

WHAT IS THE HISTORY OF PSYCHOLOGICAL TESTING?

• Charles Darwin --> Individual differences
• Wilhelm Wundt --> Standardization
• Francis Galton/Karl Pearson/Charles Spearman --> Statistical approach, Classical test theory
• James Cattell --> Mental test

HOW CAN WE DEVELOP PERSONALITY TESTS?

• Different Approaches:
  • Theoretical approach
  • Lexical approach
  • Statistical approach
• Examples:
  
  • Act frequency approach --> How often are you engaged in the following acts?
    
    • Steps: Traits are categories of acts
      
      • Act nomination
      • Prototypicality judgement
      • Recording act performance
  • Sentence items (Neo-PI-3, Costa & McCrae) --> How much do you disagree or agree with the following items?
  • Trait adjectives (Goldberg) --> How much do you disagree or agree that you are… Talkative, Warm, Moody

QUALITY ISSUES

• Validity
  • Does the scale measure what you want to measure?
  • Test validity --> factor analysis
• Reliability
  
  • Are the findings consistent and replicable?
  • Test validity --> Classical Test Theory, Item Response Theory
• Usability
  
  • Is the test ‘economical’ and communicable?

LIFESPAN DEVELOPMENT

HOW DO WE DEVELOP DISPOSITIONAL TRAITS WHEN GROWING UP?

• Reliable measurement from age 5 onwards
• Relative stability on short term, less on longer term
• Development of children and parents influence each other