Psychology Key Terms by Unit

Intro psychology exams lean on vocabulary: you are asked to name the concept, tell two similar ones apart, or apply a term to a short scenario. This glossary follows the sixteen units of Encodr's free Intro Psychology deck, and the definitions come from the deck's chapter notes. Cover the right-hand column, say each definition from memory, and check yourself.

Unit 1: What psychology is

Term	Definition
Psychology	The scientific study of the mind and behavior
Hypothesis and theory	A tentative, testable explanation; a broad explanation that evidence has repeatedly supported
Structuralism	Analyzing the basic elements of conscious experience by introspection (Titchener)
Functionalism	Asking what mental activities are for, using Darwin's idea of adaptation (James)
Behaviorism	Studying observable behavior and how learning shapes it (Watson, Skinner)
Humanism	Free will, personal growth and self-actualization (Maslow, Rogers)
Psychiatrist and clinical psychologist	A medical doctor who can prescribe medication; a doctoral-level clinician who assesses and treats with testing and therapy

Unit 2: Psychological research

Term	Definition
Case study, naturalistic observation, survey	Deep study of one person; watching behavior in its natural setting; questions given to a sample
Correlation	A relationship between two variables, summarized by r from -1 to +1
Independent and dependent variable	What the researcher manipulates; what is measured
Random assignment	Makes experimental groups comparable
Double-blind	Neither participants nor the researchers dealing with them know who gets the treatment
Descriptive and inferential statistics	Summarize collected data; judge whether a sample pattern likely holds in the population
Type I and Type II error	A false positive; a false negative
Reliability and validity	Consistency of a measure; measuring what it claims to measure
IRB and informed consent	The board reviewing human-participant research; participants learn the risks, take part voluntarily and can quit without penalty

The statistics terms come together in z-scores and percentiles explained, and the z-score calculator lets you practice.

Unit 3: Biopsychology

Term	Definition
Neuron and glia	Cells carrying electrochemical signals; cells that support them
Action potential	A fast, all-or-none impulse that fires at the threshold of excitation
Myelin	Fatty insulation made by glia that speeds signals
Agonist and antagonist	Boosts a neurotransmitter's effect; blocks it
Central and peripheral nervous system	Brain and spinal cord; the nerves linking them to muscles, organs and senses
Sympathetic and parasympathetic	Fight-or-flight arousal; rest and restore
Medulla, pons, cerebellum	The hindbrain structures
Lateralization	Some functions depending more on one hemisphere
Neuroplasticity	The brain's ability to change through new synapses, pruning, glial changes and new neurons
Epigenetics	The environment changing how genes are expressed without changing the DNA sequence

Unit 4: States of consciousness

Term	Definition
Circadian rhythm	A cycle of about 24 hours in body temperature, alertness and other functions
Suprachiasmatic nucleus	The body's clock in the hypothalamus, set by light through the retina
Sleep stages	Non-REM stages N1, N2 and N3, and REM sleep
Manifest and latent content	A dream's storyline; its hidden meaning, in Freud's theory
Insomnia	Persistent difficulty falling or staying asleep with daytime impairment
Hypnosis	A state of intense self-focus and heightened suggestibility
Tolerance and withdrawal	Needing more of a drug for the same effect; symptoms when use stops

Unit 5: Sensation and perception

Term	Definition
Sensation and perception	Receptors detect energy and transduction converts it to neural signals; the brain organizes and interprets those signals
Absolute and difference threshold	The weakest stimulus detected half the time; the smallest change detected half the time
Weber's law	The just noticeable difference is a constant proportion of the starting intensity
Sensory adaptation	Receptors responding less to a constant stimulus
Bottom-up and top-down processing	Driven by the stimulus; driven by goals, knowledge and expectation
Gestalt principles	Proximity, similarity, continuity, closure and figure-ground
Rods and cones	Dim light and motion, in the periphery; bright light, color and detail, clustered in the fovea
Trichromatic and opponent-process theory	Three cone types; opposing pairs of colors after the retina

Unit 6: Learning

Term	Definition
Learning	A relatively permanent change in behavior or knowledge that results from experience
Unconditioned stimulus and response	Naturally triggers a reflexive response, no learning needed
Conditioned stimulus and response	A neutral stimulus that, after pairing with the UCS, triggers the response
Extinction and spontaneous recovery	The CR fading when the CS appears without the UCS; its return after a rest
Positive and negative reinforcement	Adding something wanted; removing something unpleasant
Positive and negative punishment	Adding something unpleasant; removing something wanted
Shaping	Reinforcing successive approximations of a target behavior
Ratio and interval schedules	Count responses; count time
Vicarious reinforcement	Seeing a model rewarded, making imitation more likely

The first two forms of conditioning are compared side by side in classical vs operant conditioning.

Unit 7: Thinking and intelligence

Term	Definition
Concept, prototype, schema	A mental grouping of similar things; the best or most typical example; a larger cluster of related concepts
Algorithm and heuristic	A step-by-step procedure that guarantees a solution; a fast shortcut that can fail
Functional fixedness	Seeing an object only in its usual role
Confirmation bias	Favoring supporting evidence
Availability heuristic	Judging likelihood by how easily examples come to mind
Standardization and norming	Giving the test the same way to everyone; building the scale from a representative sample
IQ scale	Bell curve with a mean of 100 and a standard deviation of 15
Fluid and crystallized intelligence	Reasoning with new material; accumulated knowledge
Heritability	The share of variation in a trait within a group linked to genetic differences, not the share of one person's trait that is genetic

Unit 8: Memory

Term	Definition
Encoding, storage, retrieval	Getting information in, keeping it, getting it back out
Atkinson-Shiffrin model	Sensory memory, short-term memory and long-term memory
Working memory	Baddeley and Hitch's view of short-term memory: phonological loop, visuospatial sketchpad, episodic buffer and central executive
Explicit and implicit memory	Consciously recalled (episodic and semantic); shown in performance (procedural, priming)
Recall, recognition, relearning	Retrieval with no cues; identifying from options; faster the second time
Consolidation	Stabilizing a new memory
Proactive and retroactive interference	Old learning disrupting new; new learning disrupting old
Anterograde and retrograde amnesia	Unable to form new memories; unable to recall memories from before an injury
Massed and distributed practice	Cramming; spreading study over time

The deck notes that practice testing and spacing have strong evidence, while highlighting and rereading do not. Cramming vs spacing and the forgetting curve explain the evidence, and the retention curve simulator lets you see it.

Unit 9: Lifespan development

Term	Definition
Continuous and discontinuous development	Gradual and cumulative; distinct stages with sudden shifts
Teratogen	Any agent that can damage an embryo or fetus
Attachment styles	Ainsworth's secure, avoidant, resistant and disorganized
Assimilation and accommodation	Fitting new information into a schema; changing the schema
Piaget's stages	Sensorimotor, preoperational, concrete operational and formal operational
Erikson's psychosocial stages	Eight stages across the lifespan, each posing a social conflict
Authoritative, authoritarian, permissive, uninvolved	Baumrind's four parenting styles
Emerging adulthood	Arnett's term for about 18 to the mid-20s in industrialized societies

Unit 10: Emotion and motivation

Term	Definition
James-Lange	The body reacts first, and the felt emotion follows
Cannon-Bard	Arousal and the feeling occur at the same time
Schachter-Singer two-factor	Arousal plus a cognitive label produce the emotion
Display rules	Cultural norms about which emotions may be shown, and when
Intrinsic and extrinsic motivation	Doing something for its own sake; for an outside reward
Overjustification effect	A drop in intrinsic motivation after an external reward is added
Maslow's hierarchy	Needs ordered from physiological up to self-actualization

Unit 11: Personality

Term	Definition
Id, ego, superego	Seeks immediate satisfaction; weighs reality; the conscience
Defense mechanisms	Unconscious tactics that reduce anxiety
Big Five	Openness, conscientiousness, extroversion, agreeableness and neuroticism
Reciprocal determinism	Thoughts, behavior and environment influencing one another (Bandura)
Locus of control	Internal means outcomes are seen as controlled by yourself; external means luck or others (Rotter)
Self-report inventory and projective test	Questionnaire like the MMPI; ambiguous stimuli like the Rorschach
Temperament	Inborn, biologically based emotional and behavioral style

Unit 12: Social psychology

Term	Definition
Fundamental attribution error	Overweighing dispositions and underweighing the situation when explaining others' behavior
Actor-observer bias	Explaining others' behavior by dispositions but our own by the situation
Self-serving bias	Crediting success to yourself and blaming failure on the situation
Cognitive dissonance	Discomfort from holding inconsistent attitudes, behaviors or cognitions
Conformity, compliance, obedience	Going along with a group; with a request; with an authority
Normative and informational influence	Conforming to fit in; conforming because you think the group knows better
Groupthink and group polarization	Shifting opinions to match a perceived consensus; discussion strengthening the initial leaning
Bystander effect	Witnesses being less likely to help when others are present, through diffusion of responsibility
Prejudice, stereotype, discrimination	A negative feeling; a fixed belief; unfair behavior

Unit 13: Industrial-organizational psychology

Term	Definition
I-O psychology	How psychology and behavior shape work, and how work shapes people
Human factors	Designing machines and environments to fit human abilities
Job analysis and KSAs	A systematic study of what a job requires; knowledge, skills and abilities
Structured interview	Every candidate gets the same prepared questions with standard scoring
360-degree feedback	Ratings from supervisor, peers, direct reports and the employee
Transactional and transformational leaders	Use rewards and punishments to keep the status quo; inspire change and commitment

Unit 14: Stress, lifestyle and health

Term	Definition
General adaptation syndrome	Selye's alarm reaction, stage of resistance and stage of exhaustion
Primary and secondary appraisal	Judging whether an event is threatening, challenging or irrelevant; judging whether you can cope
Eustress and distress	Positive, motivating stress; negative stress
Problem-focused and emotion-focused coping	Acting on the stressor; managing the emotional response
Learned helplessness	Giving up after uncontrollable aversive events (Seligman and Maier)
Burnout	Emotional exhaustion, depersonalization and reduced personal accomplishment (Maslach)
Psychoneuroimmunology	Links among psychology, the nervous system and the immune system

Unit 15: Psychological disorders

Term	Definition
DSM and ICD	The American Psychiatric Association's manual; the World Health Organization's classification
Comorbidity	Two or more disorders in the same person
Diathesis-stress model	A disorder appears when a predisposed person meets adverse experience
Panic attack and panic disorder	An abrupt surge of fear peaking within about 10 minutes; repeated unexpected attacks plus at least a month of worry
Generalized anxiety disorder	Continuous, hard-to-control worry about many everyday matters for at least 6 months
Obsession and compulsion	A persistent, unwanted intrusive thought; a repetitive behavior done to reduce distress
Major depressive disorder	Depressed mood and/or loss of interest or pleasure, plus other symptoms, for at least 2 weeks
Schizophrenia	A psychotic disorder in which a person loses touch with shared reality
Personality disorder clusters	A (odd), B (dramatic) and C (anxious)

Unit 16: Therapy and treatment

Term	Definition
Psychotherapy	The umbrella term for psychological treatment of personal problems
Psychoanalysis	Freud's treatment of problems as repressed impulses and childhood conflict
Behavior, cognitive and CBT	Learning principles to change behavior; targeting distorted thoughts; the combination
Client-centered therapy	Carl Rogers's nondirective approach, offering unconditional positive regard
EBPP	Evidence-based practice in psychology: best research, clinical expertise and client characteristics
ECT and TMS	A brief controlled seizure under anesthesia; magnetic pulses, no seizure
Deinstitutionalization	The mass movement of patients out of large psychiatric institutions into community care
Stigma	Shame and negative labeling attached to mental illness

How to use the glossary

A glossary only works if you test yourself on it. Cover the definitions, retrieve each one from memory and mark the ones you miss. The testing effect is the research behind that advice, and the Encodr deck does the scheduling for you. For what each unit contains, see what's in intro psychology, and for a plan, see how to study for intro psychology.