AP Psychology Key Terms & Vocabulary

326 essential AP Psychology terms, defined — aligned to the College Board CED.

A
Absolute threshold: The minimum stimulus intensity detectable at least 50% of the time. The faintest signal you can catch.
Accommodation: Adjusting or creating a schema to incorporate new information that doesn't fit.
Acetylcholine: Neurotransmitter that enables muscle movement, learning, and memory. Linked to Alzheimer's when production declines.
Achievement vs. aptitude tests: Achievement tests measure what you've already learned; aptitude tests predict future performance.
Acquisition: The initial stage of learning the association between the neutral stimulus and the UCS in classical conditioning.
Action potential: The brief electrical impulse that travels down an axon when a neuron fires. Governed by the all-or-none principle.
Activation-synthesis theory: Dreams are the brain's attempt to make sense of random neural activity during REM sleep.
Actor-observer bias: We blame our own bad outcomes on the situation but others' on their character. Same flub, different explanation depending on whose it is.
Adverse childhood experiences (ACEs): Early sources of stress and trauma that can affect a person's mental and physical health across the lifespan. A key predictor of later health risk.
Agonist vs. antagonist: An agonist mimics or boosts a neurotransmitter's action; an antagonist blocks it. How psychoactive drugs hijack neural communication.
Agoraphobia: Intense fear of situations where escape might be hard, like open spaces, crowds, public transit, or being alone outside the home.
Algorithm: A step-by-step procedure that guarantees a solution by trying all possibilities. Slow but reliable.
All-or-none principle: A neuron either fires at full strength or not at all. Stronger stimuli mean more frequent firing, not bigger impulses.
Altruism: Selfless concern for others' welfare. Some researchers argue it's driven by social debt via the reciprocity norm and the social responsibility norm.
Amygdala: Two clusters tied to emotion, especially fear and aggression. The brain's threat detector.
Anorexia nervosa: A feeding and eating disorder marked by severe food restriction leading to dangerously low body weight and a distorted body image.
Anterograde amnesia: The inability to form new memories after an injury or onset, while older memories remain intact.
Antisocial personality disorder: A Cluster B disorder marked by a persistent disregard for, and violation of, the rights of others, often with a lack of remorse.
Anxiety disorders: Disorders marked by excessive fear or anxiety with related behavioral disturbance. In scope: specific phobia, agoraphobia, panic disorder, social anxiety disorder, and generalized anxiety disorder.
Applied behavior analysis: Treatment applying conditioning principles to change behavior and address disorders. Includes exposure therapies, aversion therapies, and token economies.
Arousal theory: People are motivated to maintain an optimal level of arousal, not too high or too low. Explains why we seek stimulation when bored and calm when overwhelmed.
Assimilation: Fitting new information into an existing schema without changing the schema.
Attachment styles: Patterns of infant bonding: secure and insecure (avoidant, anxious, disorganized). Linked to temperament and later relationships.
Attribution theory: How people explain the causes of behavior, splitting causes into dispositional (internal traits) or situational (external circumstances). Whether you see an action as 'who they are' or 'the situation they're in' drives how you judge it.
Autonomic nervous system: Governs involuntary processes (heart rate, digestion). Contains the sympathetic and parasympathetic branches.
Availability heuristic: Judging likelihood by how easily examples come to mind. Why vivid news makes rare events feel common.
B
Behavioral perspective: The view that psychology should focus on observable behavior learned through conditioning, not internal mental processes.
Belief perseverance: Clinging to a belief even after the evidence for it has been discredited. Often props itself up with confirmation bias.
Big Five: The trait model (OCEAN: Openness, Conscientiousness, Extraversion, Agreeableness, emotional stability/neuroticism) derived through factor analysis. The dominant scientific framework for personality.
Binocular depth cues: Depth cues requiring both eyes: retinal disparity (difference between each eye's image) and convergence (eyes turning inward for near objects).
Biofeedback: Using monitoring of body systems (like heart rate) to help clients learn to regulate physiological responses tied to anxiety or stress.
Biological preparedness: The predisposition to learn certain stimulus-response associations more easily than others, such as fearing snakes.
Biopsychosocial model: Any psychological problem may involve a mix of biological, psychological, and sociocultural factors. Treating only one dimension, as a doctor ignoring stress and support, misses the full picture.
Bipolar disorders: Disorders cycling between periods of mania (or hypomania) and depression. Bipolar I features full mania; Bipolar II features less severe hypomania with major depression.
Blind spot: The point where the optic nerve exits the eye, with no receptor cells. The brain fills in the gap so you don't notice.
Bottom-up processing: Perception that starts with raw sensory input and builds up to a whole. Driven by the data hitting your senses.
Brain plasticity: The brain's ability to rewire and form new connections, letting undamaged areas take over functions of damaged ones.
Brain stem: The brain's oldest structure, including the medulla, controlling basic survival functions like breathing and heartbeat.
Broaden-and-build theory: Positive emotions broaden awareness and encourage new thoughts and actions, while negative emotions narrow focus. Fredrickson's idea that good feelings build lasting resources.
Broca's area: Left-hemisphere region responsible for speech production. Damage causes Broca's aphasia, impairing the ability to speak.
Bulimia nervosa: A feeding and eating disorder marked by cycles of binge eating followed by compensatory behavior like purging.
Bystander effect: The more witnesses present, the less likely any one person is to help, due to diffusion of responsibility. Kitty Genovese's case made the concept famous.
C
Central nervous system: The brain and spinal cord. The command center that interacts with every process in the body.
Cerebellum: The 'little brain' at the rear that coordinates muscle movement, balance, and some procedural learning.
Cerebral cortex: The brain's wrinkled outer layer of higher-order thinking, split into two hemispheres and four lobes.
Change blindness: Failing to notice large changes in the environment because attention is directed elsewhere.
Chunking: Grouping information into meaningful units to expand how much short-term memory can hold. A phone number broken into segments.
Circadian rhythm: The roughly 24-hour biological clock governing the sleep-wake cycle. Jet lag and shift work throw it off.
Classical conditioning: Learning to associate two stimuli so a neutral one triggers a response. Pavlov's dogs salivating to a bell.
Cocktail party effect: Selective attention that lets you focus on one voice in a noisy room, yet snap to attention when your name is mentioned.
Cognitive dissonance: The mental discomfort of holding conflicting attitudes or acting against one's beliefs. Festinger's idea: people reduce the tension by changing the attitude or the behavior.
Cognitive map: A mental representation of the layout of one's environment. Evidence that learning can happen without reinforcement.
Cognitive restructuring: A cognitive-therapy technique of identifying and replacing distorted, maladaptive thoughts with more realistic ones.
Cognitive therapy: Therapy targeting maladaptive thoughts and beliefs, often through cognitive restructuring. Built around correcting distorted thinking like the cognitive triad.
Cognitive triad: Beck's idea that depression involves negative automatic thoughts about oneself, the world, and the future. The target of cognitive therapy.
Cognitive-behavioral therapy (CBT): Therapy combining cognitive and behavioral techniques to change both maladaptive thoughts and behaviors. Includes dialectical behavior therapy and rational-emotive behavior therapy.
Concept: A mental grouping of similar objects, events, or ideas. The basis of thought.
Conditioned response (CR): The learned reaction to the conditioned stimulus, like salivating at the bell alone.
Conditioned stimulus (CS): A formerly neutral stimulus that, after pairing with the UCS, comes to trigger a learned response.
Cones: Retinal cells in the fovea that process color and fine detail in bright light. Come in short, medium, and long wavelength types.
Confirmation bias: Seeking and favoring information that supports an existing belief while ignoring contradicting evidence. The engine behind belief perseverance.
Conformity: Adjusting behavior or thinking to match a group's unspoken norms. Distinct from obedience, which responds to a direct order from authority.
Conservation: Grasping that quantity stays the same despite changes in shape or appearance. Lacking in the preoperational stage.
Consolidation theory: Sleep, especially REM, strengthens and organizes memories from the day. One reason all-nighters backfire.
Constructive memory: Memory is rebuilt at retrieval, not played back, making it vulnerable to distortion and imagination inflation.
Context-dependent memory: Retrieval improves when you're in the same environment where you encoded the information.
Corpus callosum: The thick band of fibers connecting the brain's two hemispheres, allowing them to communicate.
Counterconditioning: A therapy technique that replaces an unwanted conditioned response with a new, desirable one. Used to treat phobias.
Critical (sensitive) period: An optimal window when certain skills, like language, are most easily acquired. Miss it and learning is much harder.
Cross-sectional research: Comparing different age groups at one point in time. Fast, but confounds age with generational differences.
Crystallized vs. fluid intelligence: Crystallized intelligence (accumulated knowledge) stays stable with age; fluid intelligence (reasoning speed) tends to decline.
D
Deindividuation: Loss of self-awareness and restraint in group situations, often when anonymous. Helps explain mob behavior.
Deinstitutionalization: The mass release of patients from hospitals and asylums in the late 20th century, driven by effective psychotropic medications and a shift to decentralized, community-based care.
Depolarization: The shift in electrical charge that occurs when a neuron fires, triggering the action potential to move down the axon.
Depressants: Psychoactive drugs (alcohol) that decrease neural activity, slowing body functions and reactions.
Diagnostic and Statistical Manual (DSM): The American Psychiatric Association's manual for classifying mental disorders, updated regularly as research advances. The standard diagnostic tool in the U.S.
Diathesis-stress model: Disorders develop when a genetic or biological vulnerability (diathesis) meets stressful life experiences (stress). Neither alone is usually enough.
Diffusion of responsibility: In a group, each person feels less personally responsible to act because responsibility is spread across everyone. A key mechanism behind the bystander effect.
Displacement: Redirecting an emotional impulse from its real target to a safer one, like yelling at a sibling after a bad day with the boss. A defense mechanism.
Display rules: Culturally learned norms for when and how emotions should be expressed. Why the same feeling looks different across cultures, genders, or ages.
Dispositional attribution: Explaining behavior by internal qualities like personality or intelligence. The opposite of situational attribution.
Dissociative disorders: Disorders involving disruptions of consciousness, memory, or identity, usually linked to trauma. In scope: dissociative amnesia (with or without fugue) and dissociative identity disorder.
Dissociative identity disorder (DID): A dissociative disorder marked by two or more distinct identities controlling behavior, typically linked to severe trauma.
Distress: Stress experienced as negative and debilitating. The harmful side of the stress response.
Divergent thinking: Generating many possible solutions to a problem. Central to creativity, versus narrowing-down convergent thinking.
Door-in-the-face technique: Making a large request that gets refused, then following with a smaller one that looks reasonable by comparison. The opposite sequencing from foot-in-the-door.
Dopamine: Neurotransmitter tied to reward, movement, and motivation. Imbalances are linked to conditions like Parkinson's and schizophrenia.
Dopamine hypothesis: Schizophrenia is linked to excess dopamine activity or heightened dopamine sensitivity in the brain. A leading biological explanation.
Drive-reduction theory: Motivation arises from the drive to reduce internal tension and restore homeostasis (balance). A hungry body is driven to eat to return to equilibrium.
E
Eclectic approach: Drawing on more than one psychological perspective when diagnosing and treating clients. Most practicing clinicians use it.
Ecological systems theory: Bronfenbrenner's model of nested social environments (microsystem, mesosystem, exosystem, macrosystem, chronosystem) influencing development.
EEG and fMRI: Brain imaging tools. EEG records electrical activity; fMRI tracks blood flow to show which regions are active.
Ego defense mechanisms: Unconscious strategies (denial, displacement, projection, rationalization, reaction formation, regression, repression, sublimation) that protect the ego from threatening thoughts or anxiety.
Egocentrism: A preoperational child's inability to take another person's point of view.
Elaboration likelihood model: Persuasion travels two routes: the central route (logic and evidence) and the peripheral route (cues like attractiveness or a celebrity). Which route works depends on how motivated the audience is to think.
Electroconvulsive therapy (ECT): A biological treatment passing brief electrical currents through the brain, used mainly for severe depression that hasn't responded to other treatments.
Emotion-focused coping: Managing the emotional reaction to stress (through deep breathing, meditation, or medication) rather than the stressor itself. Useful when the stressor can't be changed.
Endorphins: The body's natural painkillers, which also produce feelings of pleasure. Released during exercise and stress.
Environment (nurture): External experiences like family, education, and culture that shape behavior. The 'nurture' half of the equation that constantly interacts with heredity.
Erikson's psychosocial stages: Eight lifespan stages, each with a conflict to resolve (e.g., trust vs. mistrust, identity vs. role confusion).
Ethnocentrism: Judging other cultures by the standards of one's own and treating it as superior. A driver of out-group prejudice.
Eustress: Stress experienced as positive and motivating, like the buzz before a big game. Contrasts with distress.
Evolutionary perspective: Explains behavior and mental processes through natural selection, focusing on traits that boosted survival and reproductive success. Misapplied historically to justify eugenics.
Excitatory vs. inhibitory neurotransmitters: Excitatory messages make an action potential more likely; inhibitory messages make it less likely. The push-pull that regulates neural firing.
Explanatory style: The habitual pattern of how someone explains good and bad events, which can be optimistic or pessimistic. Pessimistic style is tied to higher risk of depression.
Explicit memory: Consciously recalled memory you can describe, including episodic (events) and semantic (facts) memory.
Extinction: The weakening of a conditioned response when the CS is repeatedly presented without the UCS.
Extrinsic motivation: Doing something to earn a reward or avoid punishment. Incentive theory focuses on how these external pulls drive behavior.
F
Facial-feedback hypothesis: Facial expressions can influence the emotions we feel, not just reflect them. Forcing a smile may nudge mood upward, though research findings are mixed.
Factor analysis: A statistical method that clusters correlated test items into underlying dimensions. Used to derive the Big Five personality traits.
False consensus effect: Overestimating how widely others share your beliefs and behaviors. We assume our own views are more common than they are.
Fight-flight-freeze response: The body's automatic alarm reaction to a perceived threat, mobilizing it to confront, escape, or stay still. The first stage of the general adaptation syndrome.
Fixed vs. growth mindset: A fixed mindset sees intelligence as unchangeable; a growth mindset sees it as malleable through effort, which can boost achievement.
Fixed vs. variable schedules: Fixed schedules reinforce after a set number or time; variable schedules vary it. Variable schedules are most resistant to extinction.
Flynn effect: The worldwide rise in IQ scores over generations, attributed to factors like better nutrition, health care, and education.
Foot-in-the-door technique: Securing a small request first makes a person more likely to agree to a larger one later. Compliance built one step at a time.
Forgetting curve: Ebbinghaus's finding that forgetting is rapid right after learning, then levels off over time.
Framing: How an issue is worded shapes the decision. '90% survival' feels better than '10% mortality' for the same fact.
Free association: A psychodynamic technique where the client says whatever comes to mind without censoring, letting unconscious material surface.
Frequency theory: Pitch is determined by the rate at which the entire basilar membrane fires. Best for low-pitched sounds.
Frontal lobes: Behind the forehead, controlling executive functioning, higher-order thinking, and (via the motor cortex) skeletal movement.
Functional fixedness: A mental block to using an object in a new way, hindering creative problem-solving.
Fundamental attribution error: Overestimating dispositional (internal) causes and underestimating situational ones when judging others' behavior. The classic trap: assuming the slow driver is a jerk, not that they're rushing to a hospital.
G
GABA: The brain's main inhibitory neurotransmitter, calming neural activity. Low GABA is linked to anxiety and seizures.
Gambler's fallacy: Wrongly believing that past random events change future odds, like thinking a coin is 'due' for heads.
Gate control theory: The spinal cord has a neural 'gate' that can block or allow pain signals to reach the brain. Explains why rubbing an injury can ease pain.
General adaptation syndrome (GAS): Selye's three-stage model of the body's stress response: alarm reaction (fight-flight-freeze), resistance, and exhaustion. Susceptibility to illness peaks in the exhaustion phase.
General intelligence (g): Spearman's idea that a single underlying factor drives performance across all mental abilities, versus theories of multiple intelligences.
Generalized anxiety disorder (GAD): Prolonged, nonspecific anxiety or worry not tied to any single object or situation. Free-floating dread rather than a focused fear.
Gestalt principles: Rules describing how we organize stimuli into wholes: closure, figure-ground, proximity, and similarity. The whole is more than the sum of its parts.
Ghrelin: A hormone that signals hunger to the hypothalamus, triggering the urge to eat. Works opposite to leptin.
Glial cells: Support cells that provide structure, insulation, communication, and waste transport for neurons. Often overshadowed but essential to neural function.
Glutamate: The brain's main excitatory neurotransmitter, key to learning and memory. Too much can overexcite and damage neurons.
Group polarization: Group discussion pushes members toward a more extreme version of their initial leanings. A room of mild supporters leaves as strong ones.
Groupthink: When the desire for group harmony overrides realistic appraisal of alternatives, producing bad decisions. Dissent gets suppressed to keep the peace.
H
Habituation: A decreased response to a repeated, harmless stimulus. The simplest form of learning.
Hallucinogens: Psychoactive drugs (marijuana) that distort perception and cognition without sensory input.
Halo effect: Letting one positive trait (like good looks) color overall judgment of a person. A peripheral-route persuasion cue.
Harlow's monkey studies: Research showing infant monkeys preferred a soft cloth 'mother' over a wire one with food, proving comfort matters more than feeding in attachment.
Health psychology: The field studying how psychological, behavioral, and social factors affect physical health and wellness. Bridges mind and body.
Heredity (nature): Genetic, predisposed traits you're born with that shape physical, behavioral, and mental processes. The 'nature' half of the nature-nurture interaction.
Heuristic: A mental shortcut for quick judgments. Fast but error-prone.
Higher-order conditioning: Using an established conditioned stimulus as if it were a UCS to condition a new neutral stimulus.
Hippocampus: Critical for forming new explicit (conscious) memories. Damage here can prevent making new long-term memories.
Hormones (endocrine): Chemical messengers released into the bloodstream that act like slow-acting neurotransmitters. AP-tested ones: adrenaline, leptin, ghrelin, melatonin, oxytocin.
Humanistic theory of personality: Personality centers on unconditional positive regard and the self-actualizing tendency as the main motivators. Rogers' emphasis on growth and acceptance. Note: Maslow's hierarchy of needs is out of scope for the AP exam.
Hypnosis: A focused, suggestible state shown effective for treating pain and anxiety, but not supported for recovering accurate memories or age regression.
Hypothalamus: Regulates body maintenance like hunger, thirst, body temperature, and links the nervous system to the endocrine system.
I
Identity statuses: Marcia's four ways adolescents form identity: achievement, diffusion, foreclosure, and moratorium.
Imaginary audience: An adolescent's belief that others are constantly watching and judging them. A form of adolescent egocentrism.
Implicit attitudes: Evaluations a person holds but may be unaware of or won't acknowledge. They can drive discriminatory behavior even in people who consciously reject prejudice.
Implicit memory: Memory expressed through behavior rather than conscious recall, such as procedural memory for skills like riding a bike.
Imprinting: When some animals form an attachment to the first moving object they encounter shortly after birth. Studied by Lorenz with goslings.
In-group bias: Favoring members of one's own group over outsiders. Pairs with out-group homogeneity bias, the tendency to see 'them' as all alike.
Incentive theory: Behavior is motivated by the pull of external rewards (incentives) rather than internal pushes. Explains motivation that drive-reduction can't, like eating dessert when already full.
Informational social influence: Conforming because you believe others have accurate information, especially in ambiguous situations. Going along because you think they know better.
Insight learning: Suddenly grasping a solution to a problem without trial-and-error. Kohler's chimpanzees.
Instinctive drift: The tendency for conditioned behavior to revert toward innate, instinctive responses, limiting what can be trained.
Intelligence quotient (IQ): Originally mental age divided by chronological age. Modern IQ scores are often used to identify students for educational services.
Intrinsic motivation: Doing something for its own sake, out of internal interest or satisfaction. Contrasts with extrinsic motivation.
J
Just-noticeable difference: The smallest detectable change between two stimuli. Tied to Weber's law.
Just-world phenomenon: The belief that people get what they deserve, which leads to blaming victims for their misfortune. A way of preserving the comforting idea that the world is fair.
K
Kinesthesis: The sense of the position and movement of your body parts, letting you move in a coordinated way without looking.
L
Language development stages: The universal sequence of cooing, babbling, one-word, and telegraphic speech across cultures.
Latent learning: Learning that occurs without reinforcement and stays hidden until there's a reason to use it. Demonstrated by cognitive maps.
Law of Effect: Thorndike's principle that behaviors followed by rewards are repeated, while those followed by punishment are not.
Learned helplessness: Giving up and feeling powerless after repeated, uncontrollable aversive experiences. Seligman's research; linked to depression.
Leptin: A hormone that signals satiety, reducing hunger. Balances against ghrelin to regulate eating.
Levels of processing model: Memory is stronger the more deeply information is encoded: structural (shallow), phonemic, then semantic (deepest).
Limbic system: Emotion and memory hub including the thalamus, hypothalamus, hippocampus, and amygdala.
Lobotomy: A form of psychosurgery popular in the mid-20th century but rarely if ever performed today. A cautionary example of crude biological intervention.
Locus of control: Whether a person believes outcomes come from their own actions (internal) or from luck and outside forces (external). Internal locus generally predicts greater effort and persistence.
Long-term potentiation: The strengthening of synaptic connections through repeated activation. The neural basis of learning and memory.
Longitudinal research: Following the same individuals over a long period. Reveals true change but is slow and costly.
M
Maintenance vs. elaborative rehearsal: Maintenance rehearsal is simple repetition; elaborative rehearsal connects new info to meaning, which retains it better.
Major depressive disorder: A depressive disorder marked by persistent sad or empty mood plus physical and cognitive changes lasting at least two weeks, impairing daily function.
Menarche and spermarche: The first menstrual period (menarche) and first ejaculation (spermarche), key markers of puberty.
Menopause: The natural end of menstrual cycles in adulthood, marking the close of reproductive ability.
Mental set: The tendency to approach a problem the way that worked before, even when it no longer fits.
Mere exposure effect: Repeated exposure to a stimulus increases liking for it, even with no reward attached. Why a song you ignored at first ends up your favorite.
Metacognition: Thinking about your own thinking and monitoring what you do and don't know. Key to effective studying.
Misinformation effect: Memory distortion when misleading post-event information reshapes the recollection. Demonstrated by Loftus's eyewitness studies.
Mnemonic devices: Memory aids like the method of loci that improve encoding by organizing information meaningfully.
Monocular depth cues: Depth cues needing only one eye: relative size, relative clarity, texture gradient, linear perspective, and interposition. How flat art conveys depth.
Motivational conflicts theory: Lewin's idea that choices create conflicts we must resolve: approach-approach (two good options), approach-avoidance (one option with pros and cons), and avoidance-avoidance (two bad options).
Multi-store model: Memory model proposing three stages information passes through: sensory memory, short-term memory, and long-term memory.
N
Negative symptoms: In schizophrenia, the absence of typical behaviors, such as flat affect or catatonic stupor. 'Negative' means something is missing.
Neurodevelopmental disorders: Disorders with onset during the developmental period, judged against age-appropriate behavior. In scope for the AP exam: ADHD and autism spectrum disorder.
Neuron: The basic cell that transmits information throughout the nervous system. The building block of all behavior and mental processes.
Normative social influence: Conforming to be accepted and avoid rejection, not because you think the group is right. Going along to fit in.
NREM sleep: Non-REM sleep, occurring in Stages 1 through 3, that decreases in duration as the night progresses. Includes deep restorative sleep.
O
Obedience: Complying with the directives of an authority figure. Milgram's shock studies showed how far situational authority pressure can push ordinary people.
Object permanence: Understanding that objects still exist when out of sight. Develops in the sensorimotor stage.
Observational learning: Learning by watching and imitating others, without direct reinforcement. Central to Bandura's social learning theory.
Obsessive-compulsive disorder (OCD): Marked by obsessions (intrusive thoughts) and compulsions (repetitive behaviors done to neutralize the distress). The compulsion temporarily reduces anxiety the obsession creates. Don't confuse it with obsessive-compulsive personality disorder.
Occipital lobes: Rear-of-brain lobes that process visual information. Damage can cause blindness even with healthy eyes.
Operant conditioning: Learning in which behavior is shaped by its consequences (reinforcement and punishment). Skinner's framework.
Opponent-process theory: Color vision works through opposing pairs (red/green, blue/yellow, black/white). Explains afterimages.
Overgeneralization: A language error where a child misapplies a grammar rule, like saying 'goed' instead of 'went.'
P
Panic disorder: Recurrent, unexpected panic attacks (sudden, overwhelming surges of fear with physical symptoms). Can take culture-bound forms like ataque de nervios.
Parasympathetic nervous system: The 'rest and digest' branch that calms the body and conserves energy after arousal, returning the body to baseline.
Parenting styles: Patterns of caregiving identified by research: authoritarian, authoritative, and permissive, with culturally varying effects.
Parietal lobes: Lobes containing the somatosensory cortex, processing touch sensitivity and body position.
Perceptual constancy: Perceiving objects as stable in size, shape, and color even as their retinal image changes.
Perceptual set: A mental predisposition to perceive one thing and not another, based on expectations and context.
Peripheral nervous system: All the nerves outside the brain and spinal cord, relaying messages between the CNS and the rest of the body. Splits into autonomic and somatic.
Person-centered therapy: Rogers' humanistic therapy using active listening and unconditional positive regard to support the client's growth. The therapist guides rather than directs.
Personal fable: An adolescent's sense of being uniquely special and invulnerable. A form of adolescent egocentrism.
Personality disorders: Enduring, inflexible patterns of inner experience and behavior that deviate from cultural expectations and cause distress or impairment. Grouped into three clusters: A (odd/eccentric), B (dramatic/erratic), and C (anxious/fearful).
Phonemes and morphemes: Phonemes are the smallest sound units of language; morphemes are the smallest units carrying meaning.
Piaget's stages: Four discontinuous stages of cognitive development: sensorimotor, preoperational, concrete operational, and formal operational.
Place theory: Pitch is determined by where on the cochlea's basilar membrane sound waves peak. Best for high-pitched sounds.
Positive psychology: The study of factors that lead to well-being, resilience, positive emotions, and psychological health, rather than just treating illness.
Positive symptoms: In schizophrenia, the presence of added experiences not normally there, like hallucinations, delusions, and disorganized speech. 'Positive' means added, not good.
Post-traumatic growth: Positive psychological change that can emerge from the struggle with trauma or major stress. Growth, not just recovery.
Posttraumatic stress disorder (PTSD): A trauma- and stressor-related disorder where exposure to a traumatic event causes lasting distress: hypervigilance, flashbacks, insomnia, and emotional detachment.
Primary vs. secondary reinforcers: Primary reinforcers satisfy biological needs (food); secondary reinforcers gain value through association (money).
Proactive vs. retroactive interference: Proactive interference is old learning disrupting new; retroactive is new learning disrupting old.
Problem-focused coping: Managing stress by attacking the stressor directly and working toward a solution. Effective when the problem is controllable.
Projection: Attributing your own unacceptable thoughts or feelings to someone else. A defense mechanism that keeps the threat at arm's length.
Projective test: A personality assessment using ambiguous stimuli (like the Rorschach inkblots) to probe the preconscious and unconscious mind. Critics question their reliability and validity.
Prospective memory: Memory for things you intend to do in the future, like remembering to take medication.
Prototype: The best, most typical example of a concept. A robin is a stronger prototype of 'bird' than a penguin.
Psychoactive medications: Drugs (antidepressants, antianxiety drugs, lithium, antipsychotics) that interact with specific neurotransmitters to treat biochemical causes of disorders. Can cause side effects like tardive dyskinesia.
Psychodynamic theory of personality: Personality is driven by unconscious processes and conflicts. Note: psychosexual stages are out of scope for the AP exam.
Psychodynamic therapy: Therapy that uses free association and dream interpretation to surface unconscious conflicts driving behavior. Rooted in the psychodynamic perspective.
Psychotherapy: The treatment of psychological disorders through psychological techniques rather than medication. Meta-analyses generally find it effective.
Punishment: Any consequence that decreases the likelihood of a behavior. Can be positive (adding an aversive) or negative (removing a pleasant).
R
Recall vs. recognition: Recall is retrieving memory without cues (fill-in-the-blank); recognition is identifying it among options (multiple choice).
Reciprocal determinism: Bandura's idea that behavior, personal factors (like self-efficacy), and environment all continuously influence one another. None acts alone.
Reflex arc: A neural pathway in the spinal cord where sensory neurons, interneurons, and motor neurons produce an automatic response without involving the brain. Why your hand jerks off a hot stove instantly.
Refractory period: The brief recovery phase after firing during which a neuron cannot fire again, ensuring impulses travel in one direction.
Reinforcement: Any consequence that increases the likelihood of a behavior. Can be positive (adding something) or negative (removing something).
Reinforcement schedules: Patterns of delivering reinforcement: continuous (every time) or partial (fixed/variable, interval/ratio), each shaping behavior differently.
Relative deprivation: Feeling worse off by comparison to others rather than by any objective lack. Explains why rising wealth doesn't always raise satisfaction.
Reliability: Whether a test yields consistent results over time. Includes test-retest and split-half reliability.
REM rebound: The tendency to spend more time in REM sleep after being deprived of it. Evidence the brain needs REM.
REM sleep: Paradoxical sleep with brain waves like wakefulness but a deeply relaxed body. When most dreaming happens; increases as the night goes on.
Representativeness heuristic: Judging likelihood by how well something matches a stereotype or prototype, ignoring base rates.
Repression: In psychodynamic theory, banishing distressing memories from consciousness to protect the ego.
Resting potential: The neuron's stable, negatively charged state when not firing, ready to fire once threshold is reached.
Reticular activating system: Network controlling arousal and alertness, filtering incoming stimuli to keep you awake and attentive.
Retina: The light-sensitive surface at the back of the eye where visual transduction begins.
Retrograde amnesia: The loss of memories formed before an injury or trauma.
Reuptake: The process where a neuron reabsorbs leftover neurotransmitters from the synapse. Many drugs work by blocking it.
Rods: Retinal cells in the periphery that detect shapes and movement (not color), most active in low light.
Rooting reflex: A newborn's automatic turning toward a touch on the cheek to find a nipple. A sign of on-track development.
S
Scaffolding: Vygotsky's idea of providing temporary support that helps a learner accomplish a task just beyond their current ability.
Schema: A mental framework that organizes and interprets information. Shapes perception and can distort memory.
Schizophrenia: A disorder marked by some mix of delusions, hallucinations, disorganized thinking or speech, disorganized motor behavior, and negative symptoms. Has a strong genetic and biological component.
Self-actualizing tendency: The innate drive to fulfill one's potential, a core motivator in humanistic personality theory.
Self-concept: How a person views themselves and their relationship to others. Built up from self-efficacy and self-esteem.
Self-determination theory: Motivation runs on intrinsic (internal interest) versus extrinsic (external reward) sources. Intrinsic motivation tends to sustain behavior longer.
Self-efficacy: A person's belief in their own ability to succeed at a specific task. High self-efficacy predicts persistence and effort.
Self-fulfilling prophecy: A belief that triggers behavior which makes the belief come true. A teacher who expects a student to fail may act in ways that cause the failure.
Self-serving bias: Crediting your successes to internal factors but blaming your failures on external ones. It protects the ego, which is what separates it from the fundamental attribution error.
Sensation: Detecting stimuli from the environment and transducing them into neural signals the brain can process. The raw input before perception.
Sensation-seeking theory: Motivation stems from one's need for varied, novel experiences, across types like thrill seeking, experience seeking, disinhibition, and boredom susceptibility.
Sensory adaptation: Diminished sensitivity to a constant, unchanging stimulus. Why you stop noticing a smell or the feel of your clothes.
Sensory interaction: Senses working together to influence one another, like how smell shapes the taste of food.
Sensory memory: The brief, initial recording of sensory input. Includes iconic (visual) and echoic (auditory) memory.
Separation anxiety: Heightened distress an infant shows when separated from a caregiver. A normal part of attachment.
Serial position effect: The tendency to best recall the first (primacy) and last (recency) items in a list, forgetting the middle.
Serotonin: Neurotransmitter influencing mood, sleep, and appetite. Low levels are associated with depression, which is why it's a target for many medications.
Shaping: Reinforcing successive approximations toward a desired behavior, gradually guiding it into existence.
Situational attribution: Explaining behavior by external circumstances rather than the person's traits. Knowing which attribution someone makes predicts how they'll react to the same act.
Sleep disorders: AP-tested disruptions to healthy sleep: insomnia, narcolepsy, REM sleep behavior disorder, sleep apnea, and somnambulism (sleepwalking).
Social clock: The culturally set timetable for life events like marriage or career. Shapes what counts as 'on time.'
Social comparison: Evaluating yourself by measuring against others, either upward (to those better off) or downward (to those worse off). It shapes self-esteem more than absolute standing does.
Social facilitation: The presence of others boosts performance on well-learned tasks but hurts it on difficult or new ones. Arousal helps the easy, hinders the hard.
Social loafing: People exert less effort on a task when working in a group than when working alone, since individual contribution is harder to see.
Social norms: Shared expectations and roles a society holds for how its members should behave in given situations. Breaking them is one factor in defining behavior as abnormal.
Social trap: When individuals act in their own short-term self-interest to the long-term detriment of the whole group. Think overfishing a shared lake.
Social-cognitive theory of personality: Personality is shaped by the interaction of thoughts, behavior, and environment. Bandura's framework, built on reciprocal determinism.
Somatic nervous system: Controls voluntary movement of skeletal muscles. The part you consciously command when you raise your hand.
Source amnesia: Remembering information but misattributing where it came from. A common cause of false memories.
Spacing effect: Information is retained better when study is distributed over time rather than crammed all at once. The core of how Blitz drills.
Specific phobia: An intense, focused fear of a particular object or situation, such as heights (acrophobia) or spiders (arachnophobia). Distinct from broader social or generalized anxiety.
Split-brain research: Studies on patients whose corpus callosum was severed (often to treat epilepsy), revealing that the two hemispheres specialize in different functions.
Spontaneous recovery: The reappearance of an extinguished conditioned response after a rest period.
Stage theories of development: Theories proposing development unfolds in distinct, discontinuous steps rather than a smooth continuous curve.
Standardization: Administering and scoring a test with consistent, uniform procedures so results are comparable.
State-dependent memory: Retrieval improves when your physical or emotional state matches the state during encoding.
Stereotype: A generalized belief about a group that reduces mental effort but often fuels prejudice and discrimination. Can be both the cause and the result of biased experiences.
Stereotype threat: Anxiety from fear of confirming a negative stereotype about your group, which can lower performance.
Stimulants: Psychoactive drugs (caffeine, cocaine) that increase neural activity, speeding up body functions and alertness.
Stimulus discrimination: Learning to respond only to the specific conditioned stimulus and not to similar ones.
Stimulus generalization: Responding to stimuli similar to the conditioned stimulus. Little Albert fearing all furry things.
Stress: The process of appraising and responding to threatening or challenging events. Linked to hypertension, headaches, and immune suppression when chronic.
Subjective well-being: A person's own evaluation of their happiness and life satisfaction. Practices like expressing gratitude have been shown to raise it.
Sublimation: Channeling unacceptable impulses into socially acceptable activities, such as aggression into competitive sport. Often seen as the most adaptive defense mechanism.
Sunk-cost fallacy: Continuing a losing course of action because of resources already invested.
Superordinate goals: Shared objectives that require cooperation between rival groups and reduce conflict between them. Sherif's Robbers Cave study showed common goals could dissolve hostility.
Superstitious behavior: Behavior accidentally reinforced by an unrelated consequence, creating a false sense of cause and effect.
Sympathetic nervous system: The 'fight or flight' branch that arouses the body for action, spiking heart rate and energy. Why your heart pounds before a test.
Synesthesia: A blending of senses where one sensation triggers another, such as 'seeing' colors when hearing music.
Systematic desensitization: An exposure therapy that pairs a graduated fear hierarchy with relaxation to reduce anxiety. Used to treat phobias by conditioning calm in place of fear.
T
Taste aversion: A learned avoidance of a food after it's paired with illness, often in a single trial. Shows biological preparedness.
Temporal lobes: Side lobes handling auditory and linguistic processing.
Tend-and-befriend theory: Some people respond to stress by nurturing others and seeking social connection rather than fighting or fleeing. Observed more often in women.
Teratogens: Harmful agents like drugs or viruses that can damage prenatal development and cause lasting effects.
Testing effect: Actively retrieving information through self-testing strengthens memory more than rereading. The science behind flashcards.
Thalamus: The brain's sensory relay station, routing incoming signals to the right cortex areas. Smell is the one sense that skips it.
Theory of mind: Understanding that others have their own beliefs, desires, and perspectives. Begins developing in early childhood.
Therapeutic alliance: The quality of the trusting working relationship between therapist and client. A common factor that predicts therapy success across approaches.
Threshold: The minimum stimulation needed to trigger a neural impulse. Below it, nothing fires; at or above it, the action potential goes.
Tip-of-the-tongue phenomenon: The frustrating sense that a word is retrievable but temporarily inaccessible. An example of retrieval failure.
Token economy: A behavioral technique that rewards desired behaviors with tokens exchangeable for privileges. An application of operant conditioning principles.
Tolerance: When repeated drug use requires larger doses to get the same effect. A step on the road to addiction.
Top-down processing: Perception guided by prior expectations, experience, and context. Your mind fills in what it expects.
Trait theory: Personality consists of enduring, measurable characteristics that produce typical responses to situations. Focuses on describing traits rather than explaining their origin.
Transduction: Converting physical stimuli (light, sound) into neural impulses the brain understands. The bridge from world to mind.
Trichromatic theory: Color vision arises from three cone types tuned to red, green, and blue wavelengths.
Twin, family, and adoption studies: The main research designs for teasing apart genetic versus environmental influence on behavior. Comparing relatives with known degrees of shared genes and environments.
U
Unconditional positive regard: Full acceptance and support of a person regardless of what they do, central to Rogers' humanistic view. Believed to free people to grow toward their potential.
Unconditioned response (UCR): The natural, unlearned reaction to the unconditioned stimulus, like salivating at food.
Unconditioned stimulus (UCS): A stimulus that naturally and automatically triggers a response without learning, like food causing salivation.
V
Validity: Whether a test measures what it claims to measure. Includes construct and predictive validity.
Vestibular sense: The sense of balance and body position, monitored by the semicircular canals in the inner ear.
Vicarious conditioning: Learning from the consequences others experience rather than from your own. Watching someone get rewarded or punished.
Visual cliff: An apparatus used to test depth perception in infants, suggesting depth perception emerges early.
W
Weber's law: The change needed to detect a difference is a constant proportion of the original stimulus, not a fixed amount.
Wernicke's area: Left-hemisphere region responsible for speech comprehension. Damage causes Wernicke's aphasia, impairing understanding.
Working memory model: A model of active short-term memory with a central executive directing a phonological loop and visuospatial sketchpad.
Y
Yerkes-Dodson law: Performance is best at a moderate level of arousal; too little or too much hurts it. The optimal level is lower for hard tasks than for easy ones.
Z
Zone of proximal development: Vygotsky's gap between what a learner can do alone and what they can do with guidance (scaffolding).

Where these terms show up

Every AP Psychology term below belongs to one of the units on the exam. Each unit page has sample questions that put the vocabulary to work:

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