AP Psychology · Unit 4

AP Psychology Unit 4: Social Psychology and Personality

Unit 4 covers how people influence and explain each other, and what makes individuals consistent. It's home to psychology's most famous experiments — Milgram, Asch, the bystander studies — and the big theories of personality.

Social Thinking and Attribution

Start with attribution — explaining behavior as dispositional (internal) or situational (external). Know the fundamental attribution error (over-blaming personality in others), the self-serving bias, and the actor-observer difference. For attitudes, master cognitive dissonance (Festinger), the foot-in-the-door phenomenon, and how attitudes and behavior shape each other.

Social Influence

The headline studies live here: Asch's line study (conformity to a group) and Milgram's shock experiment (obedience to authority). Add normative vs. informational social influence and group effects — social facilitation, social loafing, deindividuation, groupthink, and group polarization.

Relations: Prejudice, Aggression, Attraction, Helping

Cover prejudice and discrimination (in-group bias, stereotypes, scapegoating), influences on aggression, and the factors in attraction — proximity, the mere exposure effect, and similarity. For prosocial behavior, know the bystander effect and diffusion of responsibility from Darley and Latané.

Personality Theories

Four perspectives to compare:

• Psychodynamic (Freud): id, ego, superego, the unconscious, defense mechanisms, and psychosexual stages; plus the neo-Freudians.
• Humanistic: Maslow's hierarchy of needs and self-actualization; Rogers's unconditional positive regard.
• Trait: the Big Five (OCEAN — openness, conscientiousness, extraversion, agreeableness, neuroticism).
• Social-cognitive (Bandura): reciprocal determinism, self-efficacy, and locus of control (Rotter).

Personality Assessment

Distinguish projective tests (Rorschach, TAT) from objective inventories (the MMPI), and know the critiques of each.

How to Study Unit 4

Build a study-and-researcher table — name, study, finding — because the exam loves "which study showed X?" Then connect the social biases here to the thinking shortcuts in Unit 2: the cognitive bias test even touches attribution. Drill it all on the practice test. Finish with Unit 5: Mental and Physical Health or the units overview.

AP Psychology Unit 4 — FAQ

What is covered in AP Psychology Unit 4?

Unit 4, Social Psychology and Personality, covers how people influence and explain one another (attribution, attitudes, conformity, obedience, group behavior, prejudice, attraction, and helping) and the major theories of personality — psychodynamic, humanistic, trait, and social-cognitive.

What is the difference between conformity and obedience?

Conformity is adjusting your behavior to match a group (Asch's line study). Obedience is following the direct orders of an authority figure (Milgram's shock study). Conformity responds to peers; obedience responds to authority.

What is the fundamental attribution error?

The fundamental attribution error is overestimating personality and underestimating the situation when explaining other people's behavior — assuming someone is rude rather than just having a bad day. It contrasts with the self-serving bias we use to explain our own actions.

What are the famous studies in AP Psychology Unit 4?

Asch's conformity study, Milgram's obedience experiment, the bystander research of Darley and Latané, and Festinger's work on cognitive dissonance are the most-tested studies in Unit 4.

Catch Your Own Biases

Attribution and heuristics in action — three quick tasks that reveal your shortcuts.

Run the Cognitive Bias Test

Aligned to the College Board's redesigned AP Psychology course (2024–25). AppsychologyLab is not affiliated with the College Board.