Personality: Introduction & Trait Theories

PSI 204: Individual Differences
Course Structure:
- First 6 weeks: Personality
- Last few weeks: Intelligence and Cognition
Focus: Differences between individuals, not groups
Perspective: General population, not mental health focused

Definition: Observable characteristics; a dimension of personality used to categorize people
Example: Extrovert vs. Introvert
Consistent patterns in behavior, feelings, and thoughts
Stable across situations and over time
Distinctive relative to other people
No good or bad traits
- Traits are just skills on which each and every one of us fall, which describe, which are a way to describe our personalities.

Describe: Classify people in how they typically feel and behave (observational tool)
Predict: Predict different types of behavior (e.g., job suitability)
Explain: Explaining why a person behaves in a certain way (even though this wasn't the original aim of trait theories)

Emphasize individual differences
Focus on characteristics stable across time and situations
Measurement is key: Done through tests, mostly self-report questionnaires
Terminology: Trait, dimension, factor, and construct are roughly equivalent in this module
Dimensional: Not binary; a continuum where everyone has a value for every trait
Not categorical: you are not an introvert check box or an extrovert check
Not 1 or 0
No positive or negative to each trait. traits just make up your personality

Overarching trait (e.g., extroversion)
Middle layer: habits or narrower traits (e.g., conversational)
Specific responses (e.g., greeting strangers)
Surface traits (observable behavior) vs. source traits (fundamental aspect of personality)

Lexical Hypothesis: Important personality characteristics become part of language
Galton: Estimated 1000 words expressive of character in a dictionary
Allport and Odbert: Found ~4500 trait words in Webster's Dictionary
Problem: Too many traits. Need to identify which traits are most important.

Correlation: Association between two numerical variables or behaviors
- Correlation Coefficient: Number between -1 and 1 describing the relationship
  - 1: Perfect positive correlation
  - -1: Perfect negative correlation
  - 0: No correlation
- Correlation is not causation
Factor Analysis: Statistical method to reduce variables into factors
- Aim: Data reduction
- Simplifies relationships among variables
- Identifies common patterns in data

Questionnaire example: 20 questions
Factor analysis identifies which questions correlate strongly
Groups questions into factors
Researchers then interpret what the factors mean (e.g., anxiety)
Identifies latent variables (unobservable, underlying variables)
Starting point: Correlation matrix
Looks for variables that correlate highly within a group but weakly with variables outside the group

Used factor analysis to identify basic structures of personality
Used three types of data:
- L-data (life record data)
- Q-data (self-report questionnaire data)
- OT-data (objective test data)
Identified 16 factors of personality

Examples: Outgoing vs. Reserved, Less intelligent vs. More intelligent, Affected by feelings vs. Emotionally stable, Submission vs. Dominance
Traits seem similar across cultures and age groups
Useful for predicting behavior
Some evidence of genetic contributions
Issue: Factors were sometimes correlated with each other

Extroversion:
- Low scores: Quiet, self-contained, timid
- High scores: Smile, laugh, competitive, ambitious
Neuroticism:
- Low scores: Low anxiety
- High scores: High anxiety, worry, sadness
Conscientiousness:
- Low scores: Frequently late, change plans, unreliable
- High scores: Stick to routine, punctual, self-discipline
Agreeableness:
- Low scores: Little regard for what other people think
- High scores: Attentive to needs of others
Openness:
- Low scores: Literal, concrete, old-fashioned beliefs
- High scores: Unusual beliefs, arts-focused, metaphorical
Acronym to remember the traits: OCEAN

Data-driven and a theoretical
Personality variation occurs with five principal orthogonal axis (independent factors)
Costa and McCrae suggested that all other taxonomies could be mapped onto the five-factor model
Each five factors is decomposable to finer facets
Five broad traits do not capture all variation in human personality

There are researchers out there that are no longer claiming it's the Big Five.
Colin Young and his lab. argue for the Big Two models.
Domains (traits): neuroticism, agreeableness, and openness
- Domains are split up into two different aspects each (e.g. neuroticism = volatility and withdrawal)
Meta Traits: stability and plasticity
- Stability is the need to maintain a stable psychosocial organization to achieve various goals.
- Plasticity is the need to incorporate novel information into an organization as the situation of the individual changes both internally and externally.

Essay is actually a proposal of a new tool or method for measuring personality or cognitive abilities.
Proposal of a new tool or method for measuring personality or cognitive abilities.
You might have intuitively thought that there are some that aren't always equally well captured within the existing five-factor model
Consider a narrow trait and see where it would fit in five-factor space.
Some Traits Examples:
- Resilience, impulsivity, mindfulness
- Perfectionism, optimism, self-efficacy, rumination
- Systemizing (associated with autism)
- Emotional intelligence (EQ)