AP Psych A-Z

Acetylcholine: A neurotransmitter involved in muscle movement, learning, and memory.

Achievement Test: A test measuring knowledge or skills in a specific subject.

Action potential: A brief electrical charge that travels down an axon.

Adverse Childhood Experiences (ACEs): Traumatic events in childhood linked to long-term health and behavioral issues.

Agonist: A chemical that mimics a neurotransmitter and activates a receptor.

All-or-none principle: A neuron either fires completely or not at all.

Altruism: Unselfish concern for the welfare of others.

Alzheimer’s Disease: A progressive neurodegenerative disorder causing memory loss and cognitive decline.

Anonymity: The condition of being unidentified in a study, protecting participant identity.

Antagonist: A chemical that blocks or inhibits a neurotransmitter’s action.

Aptitude Test: A test designed to predict future performance or ability to learn.

Assimilation: Interpreting new experiences using existing schemas (Piaget).

Attitude: A learned tendency to evaluate something in a certain way (cognitive, affective, behavioral).

Autonomic nervous system: Regulates involuntary bodily functions like heartbeat and digestion.

Axon: The neuron extension that carries messages away from the cell body.

Babinski reflex: Infant reflex where the toes fan out when the foot is stroked.

Broca’s area: Brain area in the frontal lobe responsible for speech production.

Bystander effect: The tendency for individuals to be less likely to help when others are present.

Cannon-Bard theory: Emotion theory stating physiological response and emotion occur simultaneously.

Case study: In-depth analysis of a single individual or group.

Central nervous system: Composed of the brain and spinal cord; controls most functions.

Central route to persuasion: Persuasion via logical arguments and evidence.

Cocktail Party Phenomenon: The ability to focus on one voice among many, like hearing your name.

Coercion: Forcing someone to act in a certain way, often unethical in research.

Collective unconscious (include archetypes): Jung’s idea of shared, inherited reservoir of memory traces and symbols.

Confidentiality: Protecting participants’ private information in research.

Confirmation bias: Tendency to search for info that confirms one's beliefs.

Conformity (include normative): Adjusting behavior to match group norms; normative means to gain approval.

Confounding variable (aka Third Variable Problem): An outside variable that affects the outcome of a study.

Control group: The group in an experiment that does not receive the treatment.

Correlation coefficient: A statistical measure of the relationship between two variables (ranges from -1 to +1).

Debriefing: Post-study explanation of purpose and any deception to participants.

Dendrite: The neuron’s branching extensions that receive messages.

Dependent variable (DV): The variable measured in an experiment; the outcome.

Descriptive Statistics: Stats that summarize or describe characteristics of a data set (mean, median, mode).

Diffusion of responsibility: Lessened sense of personal responsibility in a group setting.

Directionality Problem: In correlations, unclear which variable causes the other.

Dopamine: Neurotransmitter linked to reward, pleasure, and movement.

Double-blind procedure: Both participants and experimenters don’t know who’s receiving treatment vs placebo.

Effect Size: A measure of the strength of a relationship or treatment impact.

Elkind’s theory of adolescent egocentrism (include imaginary audience): Teens believe others are always watching them; includes "imaginary audience" and "personal fable."

Encoding: The process of turning sensory input into memory.

Endocrine system: A system of glands that secrete hormones into the bloodstream.

Endorphins: Neurotransmitters that reduce pain and promote pleasure.

Erikson’s Psychosocial stage theory: Eight-stage theory of social development across the lifespan.

Eugenics: The now-discredited practice of selective breeding to improve human traits.

Excitatory effect: Increases the likelihood of a neuron firing an action potential.

Experiment: A research method to test cause-and-effect by manipulating variables.

Experimental group: The group that receives the treatment in an experiment.

Factor analysis: A statistical method used to identify clusters of related traits or variables.

Fixation: In Freud's theory, a persistent focus on an earlier psychosexual stage due to unresolved conflicts.

Flashbulb memory: A vivid, detailed memory of an emotionally significant event.

Fluid intelligence: The ability to reason quickly and abstractly, tends to decline with age.

Foot-in-the-door phenomenon: Tendency to comply with a large request after first agreeing to a small one.

Framing effect: Decisions are influenced by how choices are presented.

Frontal lobe: Brain region responsible for decision-making, planning, and voluntary movement.

Functional fixedness: The tendency to think of objects only in terms of their usual functions.

Fundamental attribution error: Overestimating personality and underestimating situational factors in others' behavior.

GABA (gamma-aminobutyric acid): A major inhibitory neurotransmitter that reduces neural activity.

Gardner’s multiple intelligences: Theory proposing eight independent intelligences, including linguistic, spatial, musical, and interpersonal.

Gate-control theory: The spinal cord contains a neurological "gate" that blocks or allows pain signals to reach the brain.

Gender identity: A person's sense of being male, female, or another gender.

Gender roles: Cultural expectations about what is appropriate behavior for each gender.

General adaptation syndrome (GAS): Selye's three-stage response to stress: alarm, resistance, exhaustion.

General intelligence (g): Spearman's theory that one general ability underlies all mental abilities.

Generalization (classical conditioning): Responding similarly to stimuli that resemble the conditioned stimulus.

Genotype: An organism’s genetic makeup or allele combinations.

Gestalt principles: Rules of perception that describe how we organize visual elements into groups or unified wholes.

Glial cells: Support cells in the nervous system that nourish and protect neurons.

Group polarization: Tendency for group discussion to strengthen the dominant position of members.

Groupthink: A group's desire for harmony leads to poor decision-making.

Habituation: Decreasing response to a repeated stimulus over time.

Hallucination: False sensory experiences, such as seeing something that isn’t there.

Halo effect: The tendency to let one positive trait influence perception of other traits.

Hindsight bias: The tendency to believe, after an event, that one would have predicted it ("I knew it all along").

Homeostasis: The body’s tendency to maintain a balanced internal state.

Hormones: Chemical messengers secreted by endocrine glands, affecting behavior and physiology.

Humanistic psychology: Focuses on free will, self-actualization, and human potential for growth.

Hypnosis: A state of heightened suggestibility and focused attention.

Hypothalamus: Brain region controlling hunger, thirst, temperature, and endocrine functions.

Hypothesis: A testable prediction derived from a theory.

Iconic memory: A fleeting visual memory lasting about a few tenths of a second.

Identical twins (monozygotic): Twins from the same fertilized egg, genetically identical.

Identification (Freud): Child adopts characteristics of same-sex parent as part of superego formation.

Identity vs. role confusion: Erikson’s stage (adolescence) focused on developing a personal identity.

Illusory correlation: The perception of a relationship where none exists.

Imaginary audience: Elkind’s term for adolescents’ belief that others are always watching them.

Implicit memory: Memory of skills and procedures independent of conscious recollection.

Independent variable (IV): The variable manipulated in an experiment.

Individualism: Giving priority to one's own goals over group goals; common in Western cultures.

In-group bias: Favoring one’s own group over outsiders.

Inattentional blindness: Failing to see visible objects when attention is directed elsewhere.

Incentive theory: Behavior is motivated by external rewards or punishments.

Incubation: Letting a problem sit while unconscious processing may yield a solution.

Inductive reasoning: Making generalizations from specific observations.

Inferential statistics: Techniques for determining whether findings can be generalized to a larger population.

Informed consent: Ethical principle requiring participants be told enough to choose participation.

Insomnia: Recurring problems in falling or staying asleep.

Instinct: A complex, unlearned behavior that is rigidly patterned throughout a species.

Institutional Review Board (IRB): Committee that ensures ethical standards are upheld in research.

Intelligence quotient (IQ): A score derived from standardized tests meant to measure intellectual ability.

Interference theory: Memory disruption due to overlap with other memories—can be proactive or retroactive.

Internal locus of control: Belief that one controls their own fate through effort and decisions.

Interneurons: Neurons in the brain and spinal cord that connect sensory and motor neurons.

Intrinsic motivation: Desire to perform a behavior for its own sake and personal satisfaction.

Introversion: Personality trait characterized by focus on internal thoughts, feelings, and moods.

James-Lange theory: Emotions result from awareness of physiological reactions to stimuli.

Just-world hypothesis: Belief that people get what they deserve and deserve what they get.

Karen Horney: Neo-Freudian psychologist who emphasized social relationships and rejected Freud's bias against women.

Kinesthesis: Sense of body position and movement of body parts.

Kohlberg’s stages of moral development: Theory proposing moral reasoning develops in six stages across three levels.

Latent content (Freud): The hidden psychological meaning of a dream.

Latent learning: Learning that occurs but is not shown until there is incentive to demonstrate it.

Law of effect (Thorndike): Behaviors followed by positive outcomes are more likely to recur.

Learned helplessness: Passive resignation after repeated exposure to uncontrollable events.

Learning: A relatively permanent change in behavior due to experience.

Limbic system: Brain structures involved in emotion, motivation, and memory (e.g., hippocampus, amygdala).

Longitudinal study: Research in which the same people are studied over a long period.

Long-term memory: Relatively permanent and limitless storehouse of the memory system.

Low-ball technique: Persuasion technique where agreement is secured at a low cost, then cost is raised.

Lucid dreaming: Awareness during a dream that one is dreaming, sometimes allowing control over the dream.

Lying (polygraph): Polygraphs measure physiological indicators (e.g., heart rate) of stress, not lying directly.

Major depressive disorder: A mood disorder characterized by persistent sadness and loss of interest.

Margaret Floy Washburn: First woman to earn a Ph.D. in psychology; studied animal behavior.

Maslow’s hierarchy of needs: A motivational theory with five levels from physiological needs to self-actualization.

Mean: The average of a data set; sensitive to extreme values.

Median: The middle value in a ranked data set; less affected by outliers than the mean.

Mode: The most frequently occurring score in a dataset.

Medulla oblongata: Brainstem structure that controls vital life functions like heartbeat and breathing.

Memory consolidation: The neural process of stabilizing a memory trace after acquisition.

Mere exposure effect: Repeated exposure to a stimulus increases liking for it.

Misinformation effect: When misleading information distorts one's memory of an event.

MMPI (Minnesota Multiphasic Personality Inventory): A widely used personality test for diagnosing psychological disorders.

Modeling (observational learning): Learning by watching and imitating others' behavior.

Monozygotic twins: Identical twins formed from a single fertilized egg splitting into two.

Mood-congruent memory: Tendency to recall experiences consistent with one's current mood.

Moral development: The growth of understanding right from wrong, often studied through dilemmas.

MRI (magnetic resonance imaging): Brain scan using magnetic fields to produce detailed images.

Myelin sheath: Fatty layer that covers axons and speeds up neural impulses.

Narcolepsy: Sleep disorder with sudden uncontrollable sleep attacks, often triggered by strong emotion.

Naturalistic observation: Observing subjects in their natural environment without interference.

Nature vs. nurture: Debate over whether genetics or environment shapes behavior more.

Negative correlation: As one variable increases, the other decreases.

Negative punishment: Removing a desirable stimulus to decrease a behavior (e.g., taking away a toy).

Negative reinforcement: Removing an aversive stimulus to increase a behavior (e.g., seatbelt ding stops when buckled).

Neurogenesis: The formation of new neurons in the brain.

Neuroplasticity: The brain’s ability to reorganize and form new neural connections.

Neurons: Basic building blocks of the nervous system that transmit information.

Neurotransmitters: Chemicals that transmit messages across synapses between neurons.

Night terrors: Episodes of intense fear during sleep, often with screaming and movement, typically in children.

Noam Chomsky: Linguist and cognitive scientist who proposed an innate language acquisition device and universal grammar.

Norepinephrine: Neurotransmitter involved in arousal and alertness; also a hormone in the stress response.

Normal distribution: A bell-shaped curve representing a symmetrical distribution of scores around a mean.

Normative social influence: Influence resulting from a desire to gain approval or avoid disapproval.

Object permanence: Understanding that objects continue to exist even when not seen (Piaget).

Obsessive-compulsive disorder (OCD): A disorder marked by unwanted repetitive thoughts (obsessions) and actions (compulsions).

Occipital lobe: Brain region located at the back of the head; processes visual information.

Oedipus complex: Freud's theory that young boys develop unconscious desires for their mothers and rivalry with their fathers.

Operant conditioning: Learning based on consequences, where behaviors are strengthened or weakened.

Operational definition: A precise description of how variables are measured or manipulated in a study.

Openness to experience: A Big Five personality trait involving imagination, creativity, and curiosity.

Opponent-process theory (emotion): Emotions come in pairs; one is suppressed while the other is expressed.

Opponent-process theory (vision): Color perception is controlled by opposing retinal processes (red-green, blue-yellow).

Optimism: A general expectation that good things will happen.

Out-group: Any group with which an individual does not identify.

Out-group homogeneity bias: Tendency to view members of an out-group as more similar to each other than in-group members.

Overconfidence bias: The tendency to be more confident than correct in judgments.

Panic disorder: An anxiety disorder marked by unpredictable panic attacks.

Parallel processing: The brain’s ability to process many aspects of a problem simultaneously.

Parietal lobe: Brain region that processes sensory information like touch, spatial awareness, and navigation.

Parenting styles (authoritarian, authoritative, permissive, neglectful): Four styles characterized by varying levels of responsiveness and demandingness.

Partial reinforcement: Reinforcing a response only part of the time; slower learning but more resistant to extinction.

Paul Ekman: Psychologist who studied facial expressions and identified universal emotions.

Perception: The process of organizing and interpreting sensory information.

Peripheral nervous system: All nerves outside the brain and spinal cord; includes somatic and autonomic systems.

Personality: An individual’s unique patterns of thinking, feeling, and behaving.

Personality disorders: Chronic, inflexible patterns of behavior that impair social functioning.

Personality traits: Enduring characteristics that describe an individual’s behavior (e.g., Big Five).

PET scan (positron emission tomography): Brain imaging that shows activity by detecting radioactive glucose.

Phobia: An intense, irrational fear of a specific object or situation.

Piaget’s cognitive development theory: Four-stage theory of how children’s thinking changes over time.

Place theory: Pitch perception depends on the location of vibration along the cochlea’s basilar membrane.

Plasticity: The brain's capacity to change due to experience or damage.

Positive correlation: As one variable increases, the other increases as well.

Positive punishment: Adding an aversive stimulus to decrease a behavior (e.g., adding chores).

Positive reinforcement: Adding a desirable stimulus to increase a behavior (e.g., giving praise).

Postconventional morality: Kohlberg’s highest level of moral reasoning based on universal ethical principles.

Preconventional morality: Kohlberg’s first level of moral reasoning, focused on rewards and punishments.

Prefrontal cortex: Brain area involved in planning, decision-making, and impulse control.

Prejudice: A negative attitude toward a group and its members.

Primacy effect: Tendency to remember the first items in a list better than later ones.

Primary reinforcer: A stimulus that satisfies a biological need (e.g., food, water).

Priming: The activation of certain associations, often unconsciously, that influence perception and memory.

Projection: A defense mechanism where individuals attribute their own unacceptable thoughts to others.

Proactive interference: Older information interferes with learning new information.

Procedural memory: Memory for motor skills and habits (e.g., riding a bike).

Prosocial behavior: Positive, helpful, and cooperative behavior toward others.

Prototype: A mental image or best example of a category.

Psychodynamic theory: Freud-influenced theories that emphasize unconscious motives and conflicts.

Psychological disorders: Patterns of thoughts, feelings, or behaviors that are deviant, distressful, and dysfunctional.

Psychology: The scientific study of behavior and mental processes.

Psychoneuroimmunology: Study of how psychological, neural, and endocrine processes affect health and the immune system.

Psychopharmacology: The study of drug effects on mood, sensation, behavior, and cognition.

Psychosexual stages: Freud’s developmental stages (oral, anal, phallic, latency, genital) where the id’s energies focus on specific erogenous zones.

Psychosocial development: Erikson’s theory of eight stages of social and emotional growth across the lifespan.

Psychosomatic: Physical symptoms caused or exacerbated by psychological factors.

Puberty: The period of sexual maturation during which a person becomes capable of reproduction.

Punishment: A consequence that decreases the likelihood of a behavior recurring.

Random assignment: Assigning participants to experimental or control groups by chance to minimize preexisting differences.

Random sample: A sample in which each population member has an equal chance of inclusion.

Range: The difference between the highest and lowest scores in a dataset.

Rationalization: A defense mechanism where one offers self-justifying explanations for behaviors.

Reaction formation: A defense mechanism in which the ego switches unacceptable impulses into their opposites.

Recall: A memory task involving retrieving information learned earlier (e.g., short-answer test).

Recognition: A memory task involving identifying information learned earlier (e.g., multiple-choice test).

Reciprocal determinism: Bandura’s idea that behavior, environment, and personal factors all influence each other.

Reciprocity norm: The social rule that we should return help to those who have helped us.

Reflex arc: The neural pathway controlling a reflex action, bypassing the brain.

Refractory period (neuron): A brief period after firing during which a neuron cannot fire again.

Regression: A defense mechanism in which one retreats to a more infantile psychosexual stage.

Rehearsal (maintenance): Repeating information to keep it in short-term memory.

Rehearsal (elaborative): Linking new information to existing knowledge for better memory storage.

Reinforcement: A consequence that increases the likelihood of a behavior recurring.

Reliability: The consistency of a test or research findings over time.

REM sleep: A sleep stage with vivid dreams and rapid eye movement; associated with memory consolidation.

Repression: A defense mechanism that banishes anxiety-arousing thoughts from consciousness.

Representativeness heuristic: Judging the likelihood of something based on how well it matches a prototype.

Resilience: The capacity to recover quickly from difficulties or stress.

Response bias: The tendency of a participant to respond in a particular way regardless of actual experience.

Reticular formation: A nerve network in the brainstem that plays a role in arousal and alertness.

Retina: Light-sensitive layer at the back of the eye containing photoreceptor cells.

Retroactive interference: New information interferes with remembering old information.

Retrospective study: A study that looks backward and examines exposures to suspected risk factors.

Right hemisphere: The cerebral hemisphere associated with spatial abilities, face recognition, and creativity.

Rods: Photoreceptors in the retina that detect black, white, and gray; necessary for peripheral and night vision.

Rorschach inkblot test: A projective test using ambiguous inkblots to uncover unconscious thoughts.

Sample: A subset of a population used to represent the whole.

Sampling bias: A flawed sampling process that produces an unrepresentative sample.

Scapegoat theory: Prejudice offers an outlet for anger by providing someone to blame.

Schema: A cognitive framework that helps organize and interpret information.

Schizophrenia: A severe psychological disorder marked by delusions, hallucinations, and disorganized thinking.

Secondary reinforcer: A learned reinforcer (e.g., money, praise) that gains value through association with primary reinforcers.

Selective attention: Focusing conscious awareness on a specific stimulus while ignoring others.

Self-actualization: The motivation to fulfill one’s potential, the highest level in Maslow’s hierarchy.

Self-concept: All our thoughts and feelings about ourselves; the answer to “Who am I?”

Self-efficacy: One’s belief in their ability to succeed in specific situations (Bandura).

Self-fulfilling prophecy: A belief that leads to its own fulfillment.

Self-serving bias: Tendency to attribute success to internal factors and failures to external ones.

Sensation: The process of detecting and encoding sensory input from the environment.

Sensory adaptation: Diminished sensitivity to a constant stimulus over time.

Sensory memory: The immediate, very brief recording of sensory information in the memory system.

Sensory neurons: Neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

Serotonin: A neurotransmitter involved in mood, appetite, and sleep; low levels are linked to depression.

Set point: The weight range in which your body is programmed to function optimally; influenced by genetics and biology.

Sexual orientation: An enduring sexual attraction toward members of one’s own sex, the opposite sex, or both.

Shaping: Reinforcing behaviors that are increasingly similar to the desired behavior.

Short-term memory: Memory system that holds a small amount of information for about 20–30 seconds.

Signal detection theory: Predicts how and when we detect a faint stimulus amid background noise, depending on context and experience.

Similarity: A Gestalt principle; we group similar elements together as part of the same form.

Simulation: An imitation of a real-world process or system over time, often used in experiments.

Single-blind procedure: Experimental design in which the participant does not know whether they are in the control or experimental group.

Situational attribution: Explaining behavior in terms of external circumstances rather than personal traits.

Skinner box: An operant conditioning chamber used to train animals with reinforcement or punishment.

Sleep apnea: A sleep disorder where breathing repeatedly stops and starts during sleep.

Social anxiety disorder: Intense fear of social situations and being judged by others.

Social cognitive theory: Bandura’s theory that learning occurs through observation, imitation, and modeling.

Social exchange theory: Human relationships are formed by weighing costs and benefits.

Social facilitation: Improved performance on simple tasks when others are watching.

Social loafing: Tendency for individuals to exert less effort in a group than when alone.

Social-responsibility norm: Expectation that people will help others who depend on them.

Somatic nervous system: Controls voluntary movements of skeletal muscles.

Somatoform disorders: Psychological disorders where symptoms take a physical form without a physical cause.

Source amnesia: Attributing an event to the wrong source, a cause of false memories.

Spacing effect: Information is better retained when learning is spread out over time.

Split-brain research: Studies of patients with a severed corpus callosum, revealing hemispheric specialization.

Spontaneous recovery: The return of a previously extinguished conditioned response after a rest period.

Standard deviation: A measure of variation indicating how much scores differ from the mean.

Stanford Prison Experiment: Zimbardo’s study of the power of roles and the situation on behavior.

State-dependent memory: Improved recall when in the same state of consciousness as when the memory was encoded.

Stereotype: A generalized belief about a group of people.

Stereotype threat: The risk of confirming negative stereotypes about one’s group, which can impair performance.

Stimulants: Drugs that increase neural activity and speed up body functions (e.g., caffeine, nicotine, cocaine).

Storage: The process of retaining encoded information over time.

Stranger anxiety: The fear of unfamiliar people, typically beginning around 8 months of age.

Structuralism: Early school of psychology using introspection to explore the structure of the mind.

Sublimation: A defense mechanism where socially unacceptable impulses are transformed into acceptable actions.

Substance use disorder: Continued substance craving and use despite significant life disruption or physical risk.

Sudden infant death syndrome (SIDS): The unexplained death of an apparently healthy baby during sleep.

Superego: Freud’s part of personality that represents internalized ideals and moral standards.

Surveys: Research method involving questionnaires or interviews to gather data on attitudes and behaviors.

Synapse: The junction between two neurons where neurotransmitters are released.

Syntax: The rules for combining words into grammatically sensible sentences.

Systematic desensitization: A behavioral therapy technique that pairs relaxation with gradual exposure to a feared stimulus.

Taste aversion: A learned avoidance of a particular food due to a negative experience.

Temporal lobe: Brain region responsible for auditory processing and memory.

Thalamus: The brain’s sensory relay station, directing messages to the cortex (except smell).

Thematic Apperception Test (TAT): A projective test where people create stories from ambiguous images to reveal inner feelings.

Theory of mind: Understanding that others have thoughts, feelings, and perspectives different from one’s own.

Therapeutic alliance: The bond and trust between therapist and client that facilitates effective therapy.

Token economy: Operant conditioning procedure using tokens as rewards that can be exchanged for desired items.

Tolerance: Reduced responsiveness to a drug after repeated use, requiring increased doses for the same effect.

Top-down processing: Information processing guided by higher-level mental processes, like expectations and experiences.

Trait: A characteristic pattern of behavior or disposition to feel and act in certain ways.

Transduction: Conversion of physical stimuli (like light or sound) into neural signals.

Transference: In psychoanalysis, the patient transfers feelings for others (e.g., parents) onto the therapist.

Trait theory: Personality theory that describes people’s traits rather than explaining their origins.

Type A personality: Competitive, impatient, and more prone to stress-related illnesses.

Type B personality: Relaxed, easygoing, and less likely to suffer from stress-related illness.

Unconditioned response (UCR): In classical conditioning, an automatic, unlearned reaction to a stimulus.

Unconditioned stimulus (UCS): A stimulus that naturally and automatically triggers a response.

Unconscious: Freud’s concept of thoughts, memories, and desires not within conscious awareness.

Validity: The extent to which a test measures or predicts what it is supposed to.

Variable interval schedule: In operant conditioning, reinforcement is given after an unpredictable time interval.

Variable ratio schedule: Reinforcement after an unpredictable number of responses (e.g., gambling).

Vestibular sense: The sense of body movement and balance, located in the inner ear.

Visual cliff: A device used to test depth perception in infants and young animals.

Weber’s Law: The just noticeable difference of a stimulus is a constant proportion, not a constant amount.

Wechsler Adult Intelligence Scale (WAIS): A widely used IQ test with verbal and performance subtests.

Whorf’s linguistic relativity hypothesis: Language shapes the way we think and perceive reality.

Wilhelm Wundt: Founder of modern psychology; established the first psychological lab in 1879.

Working memory: A newer understanding of short-term memory focusing on conscious processing of information.

Yerkes-Dodson law: Performance increases with arousal to a point, but too much arousal decreases performance.

Zimbardo: Psychologist who conducted the Stanford Prison Experiment on social roles and power.

Zone of proximal development: Vygotsky’s concept of the range of tasks a child can perform with guidance but not yet alone.

Zygote: The fertilized egg that begins the process of development into an embryo.

Addiction: Compulsive craving and use of a substance despite harmful consequences.

Adolescence: The transition period from childhood to adulthood, extending from puberty to independence.

Amygdala: Brain structure involved in emotion, especially fear and aggression.

Anal stage: Freud’s second psychosexual stage (18–36 months), focused on bowel and bladder control.

Anorexia nervosa: An eating disorder characterized by an intense fear of weight gain and severe food restriction.

Antidepressant drugs: Medications used to treat depression and anxiety by altering neurotransmitter levels.

Antipsychotic drugs: Medications that reduce hallucinations and delusions by affecting dopamine pathways.

Arousal theory: Motivation theory proposing people seek an optimal level of arousal for best performance.

Association areas: Brain regions involved in higher mental functions such as learning, remembering, and thinking.

Authoritarian parenting: A parenting style characterized by strict rules and little warmth.

Authoritative parenting: A balanced parenting style that combines responsiveness with reasonable demands.

Availability heuristic: Judging the likelihood of events based on how easily examples come to mind.

Aversion therapy: A behavioral treatment pairing an unpleasant stimulus with a behavior to reduce that behavior.

Avoidant personality disorder: Characterized by social inhibition and feelings of inadequacy and hypersensitivity to criticism.

Basal ganglia: Brain structures involved in movement regulation and habit formation.

Behavior genetics: The study of the relative power and limits of genetic and environmental influences on behavior.

Behavior therapy: Therapy that applies learning principles to eliminate unwanted behaviors.

Behaviorism: Psychological perspective focusing on observable behaviors and the effects of learning.

Binocular cues: Depth cues that depend on the use of both eyes (e.g., retinal disparity).

Biological perspective: Psychological view that behavior is the result of physical processes like brain function and genetics.

Bipolar disorder: A mood disorder with alternating periods of depression and mania.

Blind spot: The point on the retina where the optic nerve leaves the eye and there are no receptor cells.

Bottom-up processing: Analysis that begins with sensory receptors and works up to brain integration.

Bulimia nervosa: An eating disorder marked by binge eating followed by purging or excessive exercise.

Burnout: A state of emotional, mental, and often physical exhaustion caused by prolonged stress.

Case formulation: A clinician’s summary of a client’s psychological issues, including causes and treatment plan.

Catatonia: A state of immobility and unresponsiveness often seen in schizophrenia.

Catharsis: Emotional release; the idea that expressing emotions can reduce psychological tension.

Central tendency: A statistical measure (mean, median, mode) indicating the center of a data distribution.

Cerebellum: Brain structure responsible for coordination, balance, and fine motor skills.

Circadian rhythm: The biological clock; regular bodily rhythms occurring on a 24-hour cycle.

Classical conditioning: Learning process where two stimuli are repeatedly paired, leading to a learned response.

Client-centered therapy: Rogerian therapy emphasizing unconditional positive regard and empathy in a non-directive setting.

Cognitive dissonance: The discomfort felt when holding conflicting beliefs or behaviors.

Cognitive map: A mental representation of spatial relationships or environments.

Cognitive therapy: Therapy that teaches people more adaptive ways of thinking to change emotions and behaviors.

Collectivism: Cultural value that emphasizes group goals over individual goals; common in Eastern cultures.

Comorbidity: The presence of two or more disorders in the same individual at the same time.

Compulsion: Repetitive behavior driven by an obsession, intended to reduce anxiety.

Concept: A mental grouping of similar objects, events, or people.

Concrete operational stage: Piaget’s stage (7–11 yrs) where children gain mental operations for logical thinking.

Conservation: The understanding that quantity remains the same despite changes in shape or arrangement (Piaget).

Consolidation: The process by which memories become stable in the brain over time.

Construct validity: The extent to which a test measures the theoretical construct it claims to measure.

Context-dependent memory: Recall is improved when the context at retrieval matches the context during encoding.

Continuous reinforcement: Reinforcing a behavior every time it occurs.

Conversion disorder: A somatic disorder where psychological stress is expressed as physical symptoms with no medical cause.

Corpus callosum: The large band of neural fibers connecting the two brain hemispheres.

Crystallized intelligence: Accumulated knowledge and verbal skills; tends to increase with age.

Deindividuation: Loss of self-awareness and restraint in group situations that foster anonymity.

Delusions: False beliefs, often of persecution or grandeur, that persist despite contrary evidence.

Dementia: A group of symptoms affecting memory, thinking, and social abilities; often includes Alzheimer’s.

Determinism: The belief that all behavior is caused by preceding factors, not free will.

Developmental psychology: The study of how people grow and change throughout life.

Diagnosis: The process of identifying a disorder using signs, symptoms, and criteria (like the DSM-5).

Diffusion tensor imaging (DTI): A brain imaging method that maps white matter pathways.

Discrimination (classical conditioning): The learned ability to distinguish between different stimuli.

Discrimination (social): Unjustifiable negative behavior toward a group or its members.

Displacement: A defense mechanism where emotional impulses are redirected to a less threatening target.

Dispositional attribution: Attributing behavior to internal traits, motives, or personality.

Dissociation: A disconnection between thoughts, identity, consciousness, and memory.

Dissociative amnesia: Inability to recall important personal information, usually after trauma.

Dissociative fugue: Sudden travel away from home with memory loss and possible identity confusion.

Dissociative identity disorder (DID): A disorder marked by two or more distinct identities controlling a person’s behavior.

Disruptive mood dysregulation disorder (DMDD): A childhood disorder with severe, recurrent temper outbursts and persistent irritability.

Double approach-avoidance conflict: Choosing between two options, each with both appealing and unappealing aspects.

Drive-reduction theory: Motivation arises from the desire to reduce internal tension caused by unmet biological needs.

DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition): The standard classification system for mental disorders.

Dual-processing theory: The idea that the brain processes information on both conscious and unconscious levels.

Eclectic approach: Using techniques from various psychological theories in therapy.

Electroconvulsive therapy (ECT): A biomedical treatment for severe depression involving electrical stimulation of the brain.

Empiricism: The view that knowledge comes from experience and observation.

Endophenotype: A measurable component unseen by the unaided eye that links genetics to behavior.

Engram: The physical trace of a memory in the brain.

Environmental psychology: The study of the relationship between humans and their physical surroundings.

Episodic memory: Memory of personal experiences and specific events, including context like time and place.

Equity theory: The idea that individuals are motivated by fairness in social exchanges and relationships.

Eustress: Positive stress that can motivate and enhance performance.

Explicit memory: Memory of facts and experiences that one can consciously know and declare.

External locus of control: The belief that outside forces determine one’s fate.

False consensus effect: The tendency to overestimate how much others share our beliefs and behaviors.

Feature detectors: Specialized neurons in the visual cortex that respond to specific features like edges and angles.

Fetal alcohol syndrome (FAS): Physical and cognitive abnormalities in children caused by heavy drinking during pregnancy.

Figure-ground: A Gestalt principle where the visual system separates objects (figures) from their background (ground).

Fixation (problem solving): Inability to see a problem from a new perspective due to a mental set.

Flooding: A behavioral therapy technique involving exposure to a feared stimulus until the fear response is extinguished.

Flynn effect: The observed rise in average IQ scores over generations.

Foot-in-the-face technique: A persuasion method that begins with a large request that is likely refused, followed by a smaller one.

Forensic psychology: Application of psychological principles to legal and criminal justice systems.

Free association: A psychoanalytic technique in which the patient says whatever comes to mind to uncover unconscious material.

Freudian slip: An unintentional error regarded as revealing unconscious feelings.

Functionalism: An early school of thought focusing on how mental and behavioral processes function and help adapt to environments.

Gender dysphoria: Distress experienced when one’s gender identity does not align with their assigned sex at birth.

Genital stage: Freud’s final psychosexual stage (puberty onward), focused on mature sexual interests.

Gestalt psychology: A psychological approach that emphasizes that the whole is more than the sum of its parts.

Group therapy: A form of psychotherapy involving one or more therapists and several clients.

Health psychology: A subfield that studies how psychological factors affect health and illness.

Hippocampus: A brain structure involved in forming new memories.

Historical bias: The tendency to view past events through the lens of current norms and knowledge.

Human factors psychology: A field focused on designing products and systems that improve usability and efficiency.

Hypnagogic sensations: Sensory experiences (e.g., falling or floating) that occur during the transition to sleep.

Id: Freud’s part of the personality driven by unconscious desires and the pleasure principle.

Illusion: A false perception of reality, often studied in sensation and perception research.

In-group: A group to which one belongs and identifies with.

Insight learning: A sudden realization of a problem’s solution without trial-and-error.

Instinct theory: A theory that behavior is motivated by instincts, or unlearned fixed action patterns.

Interactionism: The perspective that behavior is a result of both individual characteristics and situational influences.

Introspection: Examining one’s own thoughts and feelings; used in early structuralist psychology.

Latent content: The symbolic meaning of dreams, according to Freud.

Learning disability: A neurological disorder affecting the ability to read, write, or do math.

Libido: In Freudian theory, the energy of the sexual drive as a component of the life instinct.

Long-term potentiation (LTP): A lasting increase in synaptic strength believed to be the basis for learning and memory.

Magnetoencephalography (MEG): A brain imaging technique that measures magnetic fields from neural activity.

Metacognition: Thinking about one’s own thinking; awareness and understanding of cognitive processes.

Mindfulness: A mental state achieved by focusing awareness on the present moment, often used in therapy.

Minnesota Multiphasic Personality Inventory (MMPI-2): An updated, standardized personality test to assess mental disorders.

Mood disorder: A category of psychological disorders involving disturbances in emotional state.

Motor neurons: Neurons that carry information from the brain and spinal cord to muscles and glands.

Multifactorial: Involving or dependent on multiple genetic and environmental factors.

Natural selection: Darwin’s principle that traits aiding survival and reproduction are more likely to be passed on.

Neuroticism: A Big Five trait associated with emotional instability and anxiety.

Norms: Socially accepted rules for behavior in a group.

Obsessions: Repetitive, intrusive thoughts or urges that cause distress.

Operant behavior: Behavior that operates on the environment to produce consequences.

Opponent-process theory (motivation): The idea that emotions are followed by opposing emotions to maintain balance.

Perceptual set: A mental predisposition to perceive one thing and not another.

Phenotype: The observable physical and behavioral traits of an organism.

Placebo effect: Improvement due to the expectation of treatment rather than the treatment itself.

Plasticity (brain): The brain’s ability to change and adapt as a result of experience.

Projective test: A personality test that provides ambiguous stimuli to reveal hidden emotions and internal conflicts.

Psychopathology: The study of mental disorders and abnormal behavior.

Relative deprivation: The perception that one is worse off relative to those with whom one compares oneself.

Theory: An explanation using principles to organize and predict behavior or events.