AP Psychology Key Terms & Study Guide

AP Psychology covers an enormous range of topics. Nine units span everything from neuroscience to social influence, with hundreds of terms, dozens of researchers, and theories that overlap in ways that can blur together by exam week. Trying to cram all of it in a few nights does not work.

The structure of the course actually works in your favor. The College Board AP Psychology course description organizes the material into clear units with defined learning objectives, and certain topics appear on the exam far more often than others. A targeted review plan built around spaced repetition will lock high-yield material into long-term memory weeks before exam day. Research supports this: a meta-analysis of 254 studies found that spacing practice outperformed massed study in nearly every condition tested.

This guide breaks down each major unit, highlights the key terms and researchers that show up most often, and gives you a realistic study timeline.

How the AP Psychology Exam Works

Know the format before you start studying:

• Section I: Multiple Choice — 100 questions in 70 minutes. Tests recognition of terms, theories, researchers, and application of concepts to scenarios.
• Section II: Free Response — 2 questions in 50 minutes. Each question presents a scenario and asks you to apply specific psychological concepts.

The multiple choice section counts for two-thirds of your score. The free response counts for one-third. Both sections pull from all nine units, though some units carry more weight than others. Biological Bases of Behavior and Clinical Psychology tend to appear heavily.

For free response, you earn points by correctly identifying and applying each concept the question asks about. Partial credit is available, so always attempt every part.

Unit 1: Scientific Foundations of Psychology (Research Methods)

This unit appears on roughly 10 to 14 percent of the exam. It tests your understanding of how psychology research is conducted and evaluated.

Key terms to know:

• Independent variable — the variable the researcher manipulates
• Dependent variable — the variable being measured
• Operational definition — a specific, measurable description of a variable
• Correlation vs. causation — correlation describes a relationship; only controlled experiments establish causation
• Random assignment vs. random sampling — assignment controls for confounding variables; sampling ensures representativeness
• Statistical significance — a result unlikely to have occurred by chance (typically p < .05)
• Standard deviation — a measure of how spread out scores are from the mean

Important researchers: Wilhelm Wundt (founded first psychology lab, 1879), William James (functionalism), Sigmund Freud (psychoanalysis), John Watson (behaviorism), B.F. Skinner (radical behaviorism), Carl Rogers and Abraham Maslow (humanistic psychology).

Common exam traps: Students confuse correlation with causation, mix up random assignment and random sampling, and forget that case studies and surveys are descriptive methods (not experiments). Know the difference between experimental and correlational research designs.

Unit 2: Biological Bases of Behavior

This is one of the most heavily tested units, accounting for 8 to 10 percent of the exam. It requires significant memorization of brain structures and neurotransmitter functions.

Key terms to know:

• Neuron structure — dendrites (receive signals), axon (transmits signals), myelin sheath (speeds transmission), synaptic gap
• Neurotransmitters — acetylcholine (muscle movement, memory), dopamine (reward, movement), serotonin (mood, sleep), GABA (inhibition), glutamate (excitation), norepinephrine (alertness), endorphins (pain relief)
• Brain structures — hippocampus (memory formation), amygdala (emotion, fear), hypothalamus (homeostasis, hunger, thirst), thalamus (sensory relay), cerebellum (coordination), Broca's area (speech production), Wernicke's area (language comprehension)
• Nervous system divisions — central (brain + spinal cord), peripheral (somatic + autonomic), sympathetic ("fight or flight"), parasympathetic ("rest and digest")
• Endocrine system — pituitary gland ("master gland"), adrenal glands (cortisol, adrenaline), thyroid (metabolism)

Important researchers: Roger Sperry (split-brain research), Paul Broca (speech production area), Carl Wernicke (language comprehension area), Phineas Gage (case study on frontal lobe damage and personality change).

Common exam topics: Expect questions about what happens when specific brain areas are damaged, which neurotransmitter is involved in a given behavior, and how the sympathetic and parasympathetic systems differ in function.

Unit 3: Sensation and Perception

This unit covers how we take in and interpret sensory information. It accounts for 6 to 8 percent of the exam.

Key terms to know:

• Absolute threshold — the minimum stimulation needed to detect a stimulus 50% of the time
• Difference threshold (JND) — the minimum difference between two stimuli needed for detection
• Weber's Law — the difference threshold is a constant proportion of the original stimulus
• Signal detection theory — detection depends on signal strength and the observer's psychological state (expectations, motivation)
• Gestalt principles — proximity, similarity, closure, continuity, figure-ground
• Top-down vs. bottom-up processing — top-down uses expectations and context; bottom-up builds from raw sensory data

Important researchers: Gustav Fechner (psychophysics), Ernst Weber (Weber's Law), the Gestalt psychologists (Wertheimer, Koffka, Kohler).

Common exam topics: Questions often present a scenario and ask which Gestalt principle applies, or ask you to distinguish between top-down and bottom-up processing. Know the specific parts of the eye and ear and what each does.

Unit 4: Learning

Learning is one of the highest-yield units for the exam, making up 7 to 9 percent. The concepts here connect to clinical psychology, developmental psychology, and social psychology.

Key terms to know:

• Classical conditioning (Pavlov) — unconditioned stimulus (US), unconditioned response (UR), conditioned stimulus (CS), conditioned response (CR), acquisition, extinction, spontaneous recovery, generalization, discrimination
• Operant conditioning (Skinner) — positive reinforcement, negative reinforcement, positive punishment, negative punishment, shaping, schedules of reinforcement (fixed-ratio, variable-ratio, fixed-interval, variable-interval)
• Observational learning (Bandura) — modeling, the Bobo doll experiment, mirror neurons
• Latent learning (Tolman) — learning that occurs without obvious reinforcement and is not demonstrated until there is motivation to do so
• Learned helplessness (Seligman) — giving up after repeated exposure to uncontrollable negative events

Important researchers: Ivan Pavlov (classical conditioning), B.F. Skinner (operant conditioning), Albert Bandura (observational learning/social learning theory), Edward Thorndike (Law of Effect), John Watson and Rosalie Rayner (Little Albert experiment).

Common exam topics: You will almost certainly see questions asking you to identify components of classical or operant conditioning in a scenario. Know the four reinforcement schedules and which produces the highest, most consistent response rates (variable-ratio).

Unit 5: Cognitive Psychology

This unit covers memory, thinking, language, and problem-solving. It accounts for 13 to 17 percent of the exam, making it the largest single unit by weight.

Key terms to know:

• Memory stages — encoding, storage, retrieval
• Memory models — Atkinson-Shiffrin model (sensory, short-term, long-term), working memory model (Baddeley)
• Types of long-term memory — explicit/declarative (semantic and episodic) vs. implicit/nondeclarative (procedural)
• Forgetting — encoding failure, storage decay, retrieval failure, interference (proactive and retroactive)
• Heuristics — availability heuristic (judging probability by how easily examples come to mind), representativeness heuristic (judging by how well something fits a prototype)
• Confirmation bias — seeking information that supports existing beliefs
• Framing effect — how the way information is presented affects decisions

Important researchers: Hermann Ebbinghaus (forgetting curve), George Miller (magic number 7 plus or minus 2 for short-term memory capacity), Elizabeth Loftus (misinformation effect, false memories), Noam Chomsky (language acquisition device), Benjamin Whorf (linguistic relativity hypothesis), Daniel Kahneman and Amos Tversky (heuristics and biases).

Common exam topics: Memory questions are frequent. Understand the difference between proactive and retroactive interference, know what the forgetting curve looks like, and be able to identify heuristics in everyday scenarios.

Unit 6: Developmental Psychology

This unit spans the entire lifespan, from prenatal development through aging. It accounts for 7 to 9 percent of the exam.

Key terms to know:

• Piaget's stages — sensorimotor (object permanence), preoperational (egocentrism, conservation), concrete operational (logical thinking about concrete events), formal operational (abstract thinking)
• Erikson's psychosocial stages — trust vs. mistrust, autonomy vs. shame/doubt, initiative vs. guilt, industry vs. inferiority, identity vs. role confusion, intimacy vs. isolation, generativity vs. stagnation, integrity vs. despair
• Attachment theory (Harlow, Ainsworth) — secure attachment, insecure-avoidant, insecure-anxious/ambivalent, disorganized
• Kohlberg's moral development — preconventional (self-interest), conventional (social norms), postconventional (universal principles)
• Vygotsky's zone of proximal development — the gap between what a child can do alone and what they can do with guidance
• Teratogens — agents that can harm prenatal development (alcohol, drugs, viruses)

Important researchers: Jean Piaget (cognitive development), Erik Erikson (psychosocial development), Lawrence Kohlberg (moral development), Harry Harlow (contact comfort in monkeys), Mary Ainsworth (Strange Situation attachment research), Lev Vygotsky (sociocultural theory), Diana Baumrind (parenting styles).

Common exam topics: Piaget's stages and Erikson's stages appear almost every year. Be able to identify which stage a child is in based on a described behavior. Know that Piaget may have underestimated children's abilities.

Unit 7: Motivation, Emotion, and Personality

This unit combines several topics under one umbrella. It accounts for 11 to 15 percent of the exam.

Key terms to know:

• Maslow's hierarchy of needs — physiological, safety, belongingness, esteem, self-actualization
• Drive-reduction theory — behavior motivated by biological needs creating drives
• Incentive theory — behavior motivated by external rewards
• James-Lange theory — experience emotion after physiological response (you feel sad because you cry)
• Cannon-Bard theory — physiological response and emotional experience happen simultaneously
• Schachter-Singer two-factor theory — emotion requires both physiological arousal and cognitive labeling
• Personality theories — Freud's psychodynamic (id, ego, superego, defense mechanisms), trait theories (Big Five: openness, conscientiousness, extraversion, agreeableness, neuroticism), humanistic (Rogers' self-concept, unconditional positive regard)

Important researchers: Abraham Maslow (hierarchy of needs), Sigmund Freud (psychoanalysis, defense mechanisms), Carl Rogers (humanistic, unconditional positive regard), Paul Ekman (universal facial expressions of emotion), Walter Mischel (marshmallow test, person-situation debate), Hans Eysenck (introversion-extraversion).

Common exam topics: Emotion theories show up regularly. Be able to apply each theory to a scenario. For personality, know the Big Five traits and be able to distinguish between psychodynamic, humanistic, and trait approaches.

Unit 8: Clinical Psychology

Clinical psychology covers psychological disorders and their treatment. It accounts for 12 to 16 percent of the exam and is one of the most heavily tested units.

Key terms to know:

• DSM-5 — the Diagnostic and Statistical Manual, used to classify psychological disorders
• Anxiety disorders — generalized anxiety disorder, panic disorder, phobias, social anxiety disorder
• Depressive disorders — major depressive disorder (persistent sadness, loss of interest, sleep and appetite changes)
• Bipolar disorder — alternating episodes of depression and mania
• Schizophrenia — positive symptoms (hallucinations, delusions) and negative symptoms (flat affect, social withdrawal)
• Dissociative disorders — dissociative identity disorder (multiple personalities)
• Therapy approaches — psychoanalytic (free association, dream analysis), cognitive-behavioral (changing thought patterns and behaviors), humanistic (client-centered therapy), biomedical (medication, ECT)
• Drug categories — antidepressants (SSRIs increase serotonin availability), antipsychotics (block dopamine), anxiolytics (enhance GABA)

Important researchers: Aaron Beck (cognitive therapy for depression), Albert Ellis (rational emotive behavior therapy), Carl Rogers (client-centered therapy), Philippe Pinel (humane treatment of mentally ill), David Rosenhan ("On Being Sane in Insane Places" study).

Common exam topics: Be able to match disorders with their symptoms and match therapy types with their underlying theories. Understand the difference between psychotherapy approaches and biomedical treatments.

Unit 9: Social Psychology

Social psychology explores how people think about, influence, and relate to one another. It accounts for 8 to 10 percent of the exam.

Key terms to know:

• Attribution theory — fundamental attribution error (overestimating personality factors, underestimating situational factors when explaining others' behavior)
• Cognitive dissonance (Festinger) — discomfort from holding contradictory beliefs, resolved by changing attitudes or behavior
• Conformity (Asch) — adjusting behavior to match group norms, even when the group is clearly wrong
• Obedience (Milgram) — following orders from an authority figure, even when it means harming someone
• Stanford Prison Experiment (Zimbardo) — demonstrated how social roles and situational forces influence behavior
• Bystander effect (Darley and Latane) — less likely to help when others are present (diffusion of responsibility)
• Groupthink — desire for group harmony overrides realistic evaluation of alternatives
• Prejudice, stereotypes, and discrimination — cognitive (stereotypes), affective (prejudice), behavioral (discrimination) components

Important researchers: Solomon Asch (conformity experiments), Stanley Milgram (obedience experiments), Philip Zimbardo (Stanford Prison Experiment), Leon Festinger (cognitive dissonance), Muzafer Sherif (Robbers Cave experiment, realistic conflict theory), Henri Tajfel (social identity theory).

Common exam topics: Milgram's and Asch's experiments appear on nearly every exam. Know the specific findings, not just the general idea. Be able to identify the fundamental attribution error in a scenario.

Your AP Psychology Study Timeline

Here is an 8-week plan assuming 20 to 30 minutes of daily review:

Weeks 8-7: Research Methods and Biological Bases. These are the most technical units, so tackle them first. Create flashcards as you review and start spaced repetition immediately. Add 15 to 20 new cards per day.

Weeks 6-5: Sensation/Perception, Learning, and Cognition. Cover three units in two weeks. Learning and Cognition are high-weight units, so spend extra time on them. Your early cards from Weeks 8-7 will already be strengthening through spaced review.

Weeks 4-3: Developmental, Motivation/Emotion/Personality, and Clinical. Another three units. Clinical Psychology is heavily tested, so give it extra attention. By now you should have 200 or more cards in your deck.

Week 2: Social Psychology and full practice exam. Cover the final unit, then take a released practice exam. Identify your weakest areas and create targeted flashcards for concepts you missed.

Week 1: Review and refine. Focus on cards you keep getting wrong. Practice free response questions using released prompts from the College Board. Work on applying concepts to novel scenarios.

Final days: Light review only. Your spaced repetition schedule should have most cards at longer intervals by now. Skim your most-missed terms and get rest.

For a more detailed day-by-day approach, see our spaced repetition exam study plan.

Study Tips for AP Psychology

Pair every researcher with their theory. AP Psychology is full of researcher-theory pairings: Pavlov and classical conditioning, Piaget and cognitive development, Milgram and obedience. Create flashcards that test both directions (researcher to theory and theory to researcher). This is active recall at its most effective for this type of material.

Use real-life examples. Psychology concepts become much easier to remember when you connect them to everyday life. Operant conditioning? Think about how your phone's notification sound acts as a conditioned stimulus. Confirmation bias? Think about how you search for evidence that supports your opinion during an argument. Retrieval practice works best when you generate your own examples rather than memorizing textbook ones.

Don't confuse similar concepts. AP Psychology is full of pairs that students mix up: positive reinforcement vs. negative reinforcement, proactive vs. retroactive interference, sensory adaptation vs. habituation, Broca's area vs. Wernicke's area. Make comparison flashcards that force you to distinguish between them. See our guide on making effective flashcards for formatting tips.

Practice free response with the "identify and apply" method. Free response questions ask you to both identify a concept and apply it to a scenario. Practice by reading a scenario, underlining the key behavior described, writing the correct psychological term, and then explaining the connection in two to three sentences. Partial credit adds up quickly.

Study smarter, not longer. Twenty minutes daily with spaced repetition beats two hours of rereading your textbook. Research by Karpicke and Roediger (2008) showed that retrieval practice produced 80 percent recall on a delayed test compared to 36 percent for repeated studying. Short, consistent sessions that force you to recall information will outperform passive review every time. If cramming is your current strategy, our spaced repetition vs. cramming comparison explains exactly why switching pays off.