Personality Psychology
Understanding individual differences: what makes you you.
What Is Personality?
Personality is the characteristic pattern of thinking, feeling, and behaving that:
- Distinguishes you from others
- Is relatively stable over time
- Is consistent across situations
Major Perspectives
Psychoanalytic (Freud)
Structure of personality:
| Component | Description | Principle |
|---|---|---|
| Id | Primitive drives | Pleasure principle |
| Ego | Reality mediator | Reality principle |
| Superego | Conscience, ideals | Morality principle |
Defense mechanisms:
| Mechanism | Description | Example |
|---|---|---|
| Repression | Blocking painful memories | Forgetting trauma |
| Denial | Refusing to accept reality | "I don't have a problem" |
| Projection | Attributing own traits to others | Cheater accuses partner |
| Rationalization | Logical excuses for behavior | "I deserved it" |
| Displacement | Redirecting emotion to safer target | Yelling at family after bad day |
| Sublimation | Channeling drives into acceptable outlets | Aggression into sports |
| Reaction formation | Acting opposite to feeling | Hatred expressed as excessive kindness |
Modern view: Defense mechanisms concept remains useful; Freud's specific theories less supported.
Trait Theory
The Big Five (OCEAN/CANOE):
| Trait | High | Low |
|---|---|---|
| Openness | Curious, creative, adventurous | Conventional, practical, routine |
| Conscientiousness | Organized, disciplined, reliable | Spontaneous, flexible, careless |
| Extraversion | Outgoing, energetic, talkative | Reserved, solitary, quiet |
| Agreeableness | Cooperative, trusting, kind | Competitive, skeptical, challenging |
| Neuroticism | Anxious, moody, vulnerable | Calm, stable, resilient |
Each trait is a spectrum, not a type.
Big Five correlates:
| Trait | Life Outcomes |
|---|---|
| High Conscientiousness | Job success, health, longevity, relationship stability |
| High Extraversion | Leadership, social success, subjective well-being |
| High Openness | Creativity, academic achievement, cultural interests |
| High Agreeableness | Relationship quality, cooperation, lower aggression |
| Low Neuroticism | Mental health, relationship stability, life satisfaction |
Humanistic (Maslow, Rogers)
Core ideas:
- People are inherently good
- Motivation toward growth and self-actualization
- Focus on subjective experience
Rogers' conditions for growth:
- Unconditional positive regard
- Empathy
- Genuineness
Social-Cognitive (Bandura)
Reciprocal determinism:
Behavior ←→ Environment ←→ Personal factors
Key concepts:
- Self-efficacy: Belief in ability to succeed
- Observational learning
- Situation-behavior interaction
Personality Assessment
Self-Report Inventories
| Test | Measures | Use |
|---|---|---|
| NEO-PI-R | Big Five | Research, clinical |
| MMPI-2 | Psychopathology | Clinical |
| 16PF | 16 factors | Research, selection |
Limitations:
- Social desirability bias
- Limited self-insight
- Reference group effects
Projective Tests
| Test | Method | Premise |
|---|---|---|
| Rorschach | Inkblots | Interpretation reveals personality |
| TAT | Ambiguous pictures | Stories reveal motives |
Limitations:
- Low reliability
- Validity questions
- Subjective interpretation
Behavioral Assessment
Observing actual behavior in relevant situations.
- Most valid for predicting specific behaviors
- Time-intensive
- Context-dependent
Personality Types
Myers-Briggs (MBTI)
| Dimension | Poles |
|---|---|
| Energy | Extraversion (E) vs. Introversion (I) |
| Information | Sensing (S) vs. Intuition (N) |
| Decisions | Thinking (T) vs. Feeling (F) |
| Lifestyle | Judging (J) vs. Perceiving (P) |
16 types (e.g., INTJ, ENFP)
Critique:
- Poor test-retest reliability
- Forces dichotomies on continuous traits
- Limited scientific support
- But useful as language for self-reflection
Enneagram
Nine personality types based on core motivations:
| Type | Core Fear | Core Desire |
|---|---|---|
| 1 Reformer | Being bad, corrupt | Being good, having integrity |
| 2 Helper | Being unloved | Being loved |
| 3 Achiever | Being worthless | Being valuable |
| 4 Individualist | Having no identity | Being unique |
| 5 Investigator | Being helpless | Being competent |
| 6 Loyalist | Being without support | Having security |
| 7 Enthusiast | Being trapped in pain | Being satisfied |
| 8 Challenger | Being controlled | Being in control |
| 9 Peacemaker | Conflict, disconnection | Inner peace |
Critique: Limited empirical support but useful for self-exploration.
Personality Development
Stability vs. Change
What stays stable:
- Rank order (if you're more extraverted than peers, you likely stay so)
- Core temperament
- Basic tendencies
What changes:
- Mean levels (most people become more conscientious with age)
- Characteristic adaptations
- Life narrative
Sources of Personality
| Source | Contribution |
|---|---|
| Genetics | ~40-60% |
| Non-shared environment | ~40-50% |
| Shared environment (family) | ~0-10% |
Surprising finding: Growing up in the same family doesn't make siblings more similar. Non-shared experiences (different friends, teachers, events) matter most.
Can Personality Change?
Yes, but:
- Change is slow (years, not weeks)
- Intentional change is difficult
- Therapy can help
- Life events can shift personality
- Change decreases with age
Most changeable: Neuroticism (with therapy), Conscientiousness (with practice)
Dark Personalities
The Dark Triad
| Trait | Description | Expression |
|---|---|---|
| Narcissism | Grandiosity, need for admiration | Self-focus, exploitation |
| Machiavellianism | Manipulation, cynicism | Strategic deception |
| Psychopathy | Callousness, impulsivity | Lack of empathy, remorse |
Subclinical levels: Many people have moderate levels. Only the extreme end is pathological.
Personality Disorders
| Cluster | Disorders | Characteristics |
|---|---|---|
| A (Odd) | Paranoid, Schizoid, Schizotypal | Eccentric, withdrawn |
| B (Dramatic) | Antisocial, Borderline, Histrionic, Narcissistic | Emotional, erratic |
| C (Anxious) | Avoidant, Dependent, Obsessive-Compulsive | Fearful, anxious |
Key: Personality disorders are extreme, inflexible patterns causing significant impairment.
Practical Applications
Know Yourself
Benefits of self-knowledge:
- Choose fitting careers
- Select compatible partners
- Understand your reactions
- Work with strengths
- Manage weaknesses
How to know yourself:
- Take validated assessments (Big Five)
- Ask for feedback
- Notice patterns
- Reflect on reactions
Work With Your Personality
| Trait | Use | Manage |
|---|---|---|
| Introversion | Deep focus, listening | Build in recharge time |
| Extraversion | Networking, energy | Avoid spreading too thin |
| High Openness | Creativity | May need to focus |
| High Conscientiousness | Reliability | Watch for rigidity |
| High Agreeableness | Relationships | Learn to say no |
| High Neuroticism | Vigilance | Practice regulation |
Understand Others
- Don't expect others to be like you
- Look for their pattern, not single behaviors
- Recognize different people need different things
- Appreciate complementary strengths
- Adjust your approach to fit their style
Personality at Work
Best fit matters more than "best" personality:
- Match role to traits
- Conscientiousness predicts performance across jobs
- Extraversion helps in social roles
- Openness helps in creative roles
Teams benefit from personality diversity.