Memly's AP® Psychology Key Terms: 300 Free Study Cards

300 terms, with the confusable pair named on 52 of them.

300 cardsLast updated 2026-08-22

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Psychology terms fail in pairs. Negative reinforcement against punishment, random assignment against random sampling, sensory adaptation against habituation, proactive against retroactive interference, positive symptoms against desirable ones. Each pair is easy to define separately and easy to swap under time pressure, and swapping them is the difference between an answer and a near miss. So these 300 cards are built on the distinction as much as the definition. All 300 open with a definition, 195 add why it matters, 54 carry a short original scenario in place of an abstract restatement, and 52 name the term this one is most often confused with and say what separates them. The weighting is 38 cards each on biological bases and cognition, 35 on research methods and statistics, 33 on social psychology, 30 on disorders and treatment, 28 each on sensation and perception, learning, and development, 22 on motivation and emotion, and 20 on personality. The disorders section describes what the categories are, how classification works, and the models used to explain them. It does not turn symptoms into a diagnosis, because that is a judgement for a qualified professional and no flashcard can make it. Cards are tagged by area and sub-topic, so you can drill just the conditioning schedules, just the attribution biases, or just the memory effects, and the pairs that keep swapping keep coming back until they stop.

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Showing 100 representative cards from the full 300-card deck.

Front	Back
Operational definition	Definition: A statement of exactly how a variable is measured or manipulated in a particular study. Example: Defining anxiety as a score on a published rating scale rather than as a feeling. Why it matters: Two studies claiming to measure the same thing may not, so the operational definition is what makes a finding checkable.
Independent and dependent variables	Definition: The independent variable is manipulated by the researcher, and the dependent variable is measured to see whether it responded. Example: Varying how long people study a word list and measuring how many words they recall.
Random assignment	Definition: Allocating participants to conditions by chance, so groups differ only randomly at the start. Often confused with: Random sampling, which is about who enters the study. Assignment supports causal claims, sampling supports generalization.
Control group in psychological research	Definition: A comparison group that does not receive the treatment, against which the experimental group is judged. Why it matters: Without it, a change over time cannot be separated from the effect of the manipulation.
Experimenter expectancy effect	Definition: Unintended influence of a researcher's expectations on participants' behaviour or on how it is recorded. Example: A researcher who expects a faster response timing that group slightly more generously.
Correlational study	Definition: A design measuring two variables to see whether they vary together, without manipulating either. Why it matters: It can establish that a relationship exists and cannot establish which direction it runs, or whether a third variable produces both.
Case study	Definition: An intensive examination of one individual or a small group. Why it matters: It is valuable for rare conditions and cannot support a general claim, since one case cannot show how typical it is.
Longitudinal and cross-sectional designs	Definition: A longitudinal design follows the same people over time. A cross-sectional design compares different age groups at one time. Why it matters: Cross-sectional differences may reflect the era people grew up in rather than age itself, which is the cohort problem longitudinal work avoids.
Measures of central tendency	Definition: The mean, median and mode, each summarizing where a distribution centres. Why it matters: The mean is pulled by extreme scores while the median is not, so a skewed distribution is better summarized by the median.
Standard deviation as a measure of spread	Definition: A summary of how far scores typically lie from the mean. Why it matters: Two distributions can share a mean and differ entirely in spread, so a mean quoted without it is incomplete.
Correlation coefficient	Definition: A number between minus one and one describing the strength and direction of a linear relationship. Why it matters: The sign gives direction and the distance from zero gives strength, so a strong negative relationship is not a weak one.
Illusory correlation	Definition: Perceiving a relationship between two variables where none exists, or a stronger one than the data support. Example: Believing that unusual events cluster on particular days because those coincidences are the ones remembered.
Reliability of a measure	Definition: The consistency of a measure, across occasions, across items, or across raters. Why it matters: A measure can be perfectly consistent and consistently measure the wrong thing, so reliability does not imply validity.
Informed consent	Definition: Agreement to take part given with adequate knowledge of what participation involves. Why it matters: It requires that a participant could reasonably decide, which is why consent obtained through incomplete information is treated as a separate problem.
Confidentiality in research	Definition: Protecting participants' identities and data from disclosure. Often confused with: Anonymity, where the researcher cannot identify participants at all. Confidentiality means the researcher can and undertakes not to.
Medulla	Definition: A hindbrain structure controlling automatic functions including heartbeat and breathing. Why it matters: Damage here is life-threatening in a way that damage to much larger cortical areas may not be, so importance does not track size.
Reticular formation	Definition: A network running through the brainstem that governs arousal and alertness. Why it matters: It filters incoming signals rather than carrying them, which is why it affects whether a stimulus is noticed at all.
Hypothalamus in behaviour	Definition: A small structure regulating hunger, thirst, temperature and sexual behaviour, and linking the nervous and endocrine systems. Why it matters: It converts a bodily state into a motivated behaviour, which is why it appears in both biological and motivational topics.
Amygdala	Definition: A structure involved in processing emotionally significant events, particularly fear and threat. Example: Reacting to a shape on a path before consciously recognizing what it is.
Frontal lobe functions	Definition: The cortical region associated with planning, judgement, working memory and voluntary movement. Why it matters: Its association areas mature late relative to other regions, which is a common explanation for age differences in impulse control.
Occipital lobe functions	Definition: The cortical region where visual information is processed. Why it matters: It sits at the back of the head, far from the eyes, so a blow there can affect vision without any injury to the eye.
Motor cortex and somatosensory cortex	Definition: Adjacent strips of cortex, one sending movement commands and the other receiving body sensation, each mapped to body regions. Why it matters: Area is allocated by sensitivity and precision rather than by body size, which is why the hands and lips occupy so much of both.
Wernicke's area	Definition: A temporal region associated with understanding language. Why it matters: Damage here can leave speech fluent but meaning disturbed, which is the pattern that separates the two language areas.
Corpus callosum and hemispheric communication	Definition: The bundle of fibres connecting the two cerebral hemispheres. Why it matters: Severing it leaves each hemisphere working with information the other cannot access, which is what made split-brain research informative.
Split-brain findings	Definition: Results from people whose hemispheres were surgically separated, showing each hemisphere can process information independently. Why it matters: The separated hemispheres could respond to different stimuli without the other knowing, which is direct evidence for lateralized function.
Electroencephalography	Definition: Recording electrical activity from the scalp. Why it matters: It has excellent timing and poor spatial resolution, so it shows when something happened far better than where.
Behaviour genetics	Definition: The study of how far differences between people in a trait relate to genetic differences. Often confused with: Claims about individuals. Estimates describe variation within a population and say nothing about any one person.
Neurotransmitter roles in behaviour	Definition: Different transmitters are associated with different behavioural functions, such as movement and reward, mood, arousal, and inhibition. Watch out: One transmitter is never responsible for one feeling, since each acts at many sites through many receptor types.
Serotonin in behaviour	Definition: A transmitter associated with mood, appetite and sleep. Watch out: The relationship with mood is far less direct than popular accounts suggest, and the simple deficiency explanation is not well supported.
Endorphins	Definition: Naturally produced substances that reduce pain and can produce a sense of wellbeing. Example: Discomfort noticed only after finishing a long run rather than during it.
Rapid eye movement sleep	Definition: A stage with rapid eye movements, brain activity resembling waking, and greatly reduced muscle tone. Why it matters: The loss of muscle tone is why vivid dreaming is not acted out, so the paralysis is a feature rather than an oddity.
Sensation and perception distinguished	Definition: Sensation is the detection of physical energy by receptors. Perception is the organization and interpretation of that input. Example: Two people receive the same pattern of light from an ambiguous figure and see different objects.
Difference threshold	Definition: The smallest change in a stimulus that can be detected. Why it matters: It grows in proportion to the original intensity, so a change detectable in a quiet room is missed in a loud one.
Signal detection theory	Definition: An account in which detection depends on both sensitivity and a decision criterion influenced by expectation and consequences. Why it matters: It explains why the same person detects differently when a miss is costly, which a fixed threshold cannot.
Structure of the eye in vision	Definition: Light passes the cornea and lens, which focus an inverted image on the retina where receptors sit. Why it matters: The image is inverted and reversed at the retina, so the upright world is a product of processing rather than of optics.
Blind spot	Definition: The retinal region where the optic nerve exits, containing no receptors. Why it matters: It is not experienced as a gap because the visual system fills it in, which is direct evidence that perception constructs rather than records.
Conduction and sensorineural hearing loss	Definition: Conduction loss involves the mechanical transmission of sound. Sensorineural loss involves the receptors or the auditory nerve. Why it matters: The distinction is about where the pathway is interrupted, which is why amplification helps one more than the other.
Bottom-up and top-down processing	Definition: Bottom-up processing builds a percept from sensory features. Top-down processing uses expectation and prior knowledge to interpret it. Example: Reading handwriting that is illegible in isolation but obvious within a familiar phrase.
Inattentional blindness	Definition: Failing to notice a visible object because attention is directed elsewhere. Why it matters: The object is fully in view and the failure is attentional rather than visual, which is why looking is not the same as seeing.
Gestalt principle of figure and ground	Definition: Organizing a scene into an object of focus and a background. Why it matters: The assignment can reverse in ambiguous images, showing that the division is imposed rather than present in the input.
Binocular depth cues	Definition: Depth information available only from two eyes, chiefly the slight difference between the two retinal images and the inward turn of the eyes for near objects. Why it matters: They work best at close range, which is why depth further away relies on the monocular cues.
Size constancy and visual illusions	Definition: Illusions in which distance cues lead the system to scale an object's apparent size. Why it matters: The illusion follows from a mechanism that is usually correct, so it is a by-product of accurate perception rather than a flaw.
Perceptual adaptation	Definition: Adjusting to an altered perceptual input, such as a displaced visual field, until coordinated action is restored. Why it matters: It shows the mapping between sensation and action is learned and revisable rather than fixed.
Classical conditioning	Definition: Learning in which a neutral stimulus comes to elicit a response after being paired with a stimulus that already produces it. Example: A cat running to the kitchen at the sound of a drawer that is always opened before feeding.
Conditioned stimulus and response	Definition: A previously neutral stimulus that has come to produce a learned reaction, and that reaction. Watch out: The conditioned response often resembles the unconditioned one but is not identical, and it is defined by having been learned.
Extinction and spontaneous recovery	Definition: The conditioned response weakens when the pairing stops, and can reappear after a rest period. Why it matters: Recovery shows the original association was suppressed rather than erased, which is why extinction is not unlearning.
Taste aversion learning	Definition: A strong association formed between a food and illness, often after a single pairing and with a long delay between them. Why it matters: It violates the usual requirements for close timing and repetition, which is evidence that organisms are biologically prepared to learn some associations more readily.
Reinforcement	Definition: Any consequence that makes the preceding behaviour more likely. Watch out: It is defined by its effect, not by whether it seems pleasant, so a consequence is reinforcing only if the behaviour increases.
Punishment	Definition: A consequence that makes the preceding behaviour less likely, by adding something unpleasant or removing something desired. Often confused with: Negative reinforcement. Punishment decreases behaviour and reinforcement increases it, regardless of whether something is added or removed.
Shaping	Definition: Reinforcing successive approximations to a target behaviour. Why it matters: It allows behaviour that has never occurred to be trained, which simple reinforcement cannot do because there is nothing to reinforce.
Fixed and variable interval schedules	Definition: A fixed interval reinforces the first response after a set time. A variable interval reinforces after unpredictable periods. Example: Checking a delivery tracker rarely at first and constantly near the promised time reflects the fixed interval pattern.
Observational learning	Definition: Learning by watching others and the consequences their behaviour produces. Why it matters: It requires no direct reinforcement of the learner, which is why behaviour can be acquired before it is ever performed.
Latent learning	Definition: Learning that occurs without reinforcement and is not shown until there is reason to use it. Why it matters: It separates learning from performance, which strict behavioural accounts had treated as the same thing.
Learned helplessness	Definition: A reduced tendency to attempt escape or control after repeated experience that outcomes are independent of one's actions. Why it matters: The learning is about controllability rather than about the unpleasant events themselves, which is why it transfers to new situations.
Biological preparedness	Definition: A predisposition to learn some associations more readily than others. Why it matters: Associations that would have mattered for survival are learned faster, which is why fears of some stimuli are acquired more easily than others.
Encoding, storage and retrieval	Definition: The three stages of memory, getting information in, holding it, and getting it back out. Why it matters: A failure can occur at any stage, so forgetting a name may mean it was never encoded rather than that it has been lost.
Short-term and working memory	Definition: Short-term memory holds a small amount briefly. Working memory adds active manipulation of that content. Often confused with: One another. Working memory is the newer account and describes doing something with the information, not just holding it.
Rehearsal	Definition: Repeating information to maintain it, or relating it to what is already known. Why it matters: Simple repetition maintains but transfers poorly, while relating information to meaning produces far better later recall.
Long-term memory	Definition: A store of very large capacity holding information over long periods. Why it matters: Its limits are on retrieval rather than on capacity, which is why a forgotten item can resurface with the right cue.
Procedural memory	Definition: Memory for how to perform a skill, expressed through action rather than description. Why it matters: It is often difficult to verbalize, which is why explaining a well-practised skill can interfere with performing it.
Spacing effect	Definition: Better long-term retention from study distributed over time than from the same total time in one session. Why it matters: Massed study feels more effective because it produces fluency during the session, which is why the better method feels worse while doing it.
Concept and prototype	Definition: A concept is a mental grouping of similar items. A prototype is the best example of that category. Why it matters: Items resembling the prototype are categorized faster, which is why an unusual member of a category is recognized more slowly.
Confirmation bias	Definition: Seeking or weighting information that supports an existing belief. Example: Testing a rule only with cases expected to fit it rather than with cases that could break it.
Overconfidence	Definition: Greater certainty in one's judgements than accuracy warrants. Why it matters: It is largely unrelated to actual accuracy, which is why feeling sure is weak evidence of being right.
Phonemes and morphemes	Definition: Phonemes are the smallest sound units that distinguish meaning. Morphemes are the smallest units carrying meaning. Example: The ending marking a plural is a morpheme, and it may consist of a single phoneme.
Drive-reduction theory	Definition: The account that a physiological need creates a drive that motivates behaviour to restore balance. Why it matters: It explains hunger and thirst well and explains curiosity poorly, since exploration raises rather than reduces arousal.
Self-determination in motivation	Definition: An account emphasizing autonomy, competence and relatedness as sources of sustained motivation. Why it matters: It predicts that controlling rewards undermine motivation, which links it to the overjustification finding.
Components of emotion	Definition: Emotion is generally described as having physiological, expressive and cognitive components. Why it matters: Theories of emotion differ mainly in the order they place these in, so the components are the common ground.
Two-factor account of emotion	Definition: The proposal that emotion requires both physiological arousal and a cognitive label for that arousal. Why it matters: It predicts that the same arousal can be experienced as different emotions depending on the explanation available.
General adaptation syndrome	Definition: A three-stage description of the response to prolonged stress, moving through alarm, resistance and exhaustion. Why it matters: It describes a common pattern regardless of the stressor, which is what made it influential.
Nature and nurture in development	Definition: The question of how inherited and environmental influences combine to produce a characteristic. Why it matters: The modern framing is interaction rather than proportion, so asking which matters more is treated as the wrong question.
Maturation	Definition: Biologically driven development following a largely fixed sequence relatively independent of experience. Example: The order in which motor milestones appear is highly consistent while their timing varies.
Piaget's sensorimotor stage	Definition: The first period, in which understanding is built through action and sensation. Key development: Object permanence, the understanding that things continue to exist when out of sight.
Piaget's concrete operational stage	Definition: A period in which logical operations become available for concrete situations. Why it matters: Reasoning works well with real objects and poorly with hypotheticals, which is the boundary that defines the stage.
Vygotsky's zone of proximal development	Definition: The range between what a learner can do alone and what they can do with guidance. Why it matters: It places development in the social interaction rather than inside the individual, which is the main contrast with Piaget's account.
Attachment	Definition: An enduring emotional bond between an infant and a caregiver. Why it matters: Evidence indicates it forms around comfort and responsiveness rather than around feeding alone.
Erikson's psychosocial stages	Definition: A sequence of periods each framed around a central social conflict, spanning the whole lifespan. Why it matters: It extends development beyond childhood, which distinguishes it from accounts that end at adolescence.
Psychodynamic approach to personality	Definition: An approach emphasizing unconscious processes and early experience as determinants of personality. Watch out: Its central claims are difficult to test directly, which is the principal scientific criticism made of it.
Humanistic approach to personality	Definition: An approach emphasizing subjective experience, personal growth and the drive toward fulfilling one's potential. Why it matters: It was framed as an alternative to accounts that reduced people to drives or to conditioning histories.
The five-factor model	Definition: A widely used trait framework with five broad dimensions covering openness, conscientiousness, extraversion, agreeableness and emotional stability. Why it matters: The dimensions emerged from statistical analysis of descriptive terms rather than from a theory of causes.
Self-efficacy	Definition: A person's belief in their capacity to succeed at a specific task. Often confused with: Self-esteem, which is a general evaluation of worth. Self-efficacy is task-specific and can be high in one domain and low in another.
Self-report personality inventories	Definition: Questionnaires in which people describe their own characteristics, scored against comparison groups. Watch out: They are open to social desirability, which is why some include measures designed to detect it.
Attribution	Definition: The process of explaining the causes of behaviour, either in terms of the person or of the situation. Why it matters: The explanation chosen shapes the response, so the same act draws sympathy or blame depending on the attribution made.
Cognitive dissonance	Definition: Discomfort arising from holding inconsistent beliefs, or from acting against a belief, which motivates a change in one of them. Why it matters: The change usually falls on the attitude rather than the action, because the action has already happened.
Conformity	Definition: Adjusting behaviour or judgement to match a group. Why it matters: It occurs even when the group is plainly incorrect, which is why the classic demonstrations used unambiguous tasks.
Ethical questions raised by classic social research	Definition: Several influential studies would not receive approval today, on grounds of deception, distress and the difficulty of withdrawing. Why it matters: The findings are taught alongside the objections, since the ethics are part of what the field learned from them.
Deindividuation	Definition: Reduced self-awareness and restraint in situations offering anonymity and group arousal. Example: Behaviour in a large anonymous crowd that the same person would not show alone.
Bystander effect	Definition: Reduced likelihood that any individual helps as the number of witnesses increases. Why it matters: The chance that someone helps may not fall, while the chance that any particular person does clearly falls.
Altruism	Definition: Acting to benefit another at a cost to oneself. Why it matters: Whether genuinely selfless motives exist is debated, since helping also relieves the helper's own discomfort.
Out-group homogeneity effect	Definition: Perceiving members of another group as more alike than members of one's own. Why it matters: It is largely explained by unequal exposure, so it can appear without any hostility.
Scapegoat explanation of prejudice	Definition: The proposal that frustration is redirected toward a group that is not its source. Why it matters: It predicts prejudice should rise under economic strain, which is a testable consequence rather than a description.
Defining a psychological disorder	Definition: Definitions generally combine deviation from a norm, personal distress, and impaired functioning, none of which is sufficient alone. Why it matters: Each criterion fails in some case, which is why the boundary is described as a judgement rather than a measurement.
Diathesis-stress model	Definition: The proposal that a predisposition combines with environmental stress to produce a condition. Why it matters: It explains why the same predisposition leads to different outcomes in different circumstances, which a purely biological account cannot.
Anxiety-related conditions as a category	Definition: A grouping unified by persistent anxiety or fear that is disproportionate and interferes with functioning. Why it matters: The grouping is by the central feature rather than by cause, which is why several different accounts of origin coexist within it.
Obsessive-compulsive conditions as a category	Definition: A grouping characterized by intrusive unwanted thoughts and repetitive acts performed to reduce the distress they cause. Why it matters: The acts are understood as maintaining the cycle by preventing the distress from subsiding on its own.
Bipolar conditions as a category	Definition: A grouping defined by periods of markedly elevated or irritable mood and activity alongside periods of low mood. Often confused with: Ordinary mood variation. The category concerns sustained episodes representing a clear change from usual functioning.
Schizophrenia spectrum as a category	Definition: A grouping involving disturbances of thought, perception and behaviour representing a marked departure from previous functioning. Why it matters: It is a spectrum rather than a single condition, so presentations within it vary widely.
Psychodynamic therapy as an approach	Definition: An approach seeking insight into unconscious conflicts and their origins in earlier experience. Why it matters: Its aim is understanding rather than symptom removal, which is why its outcomes are assessed differently from briefer approaches.
Systematic desensitization	Definition: A behavioural technique pairing gradual exposure to a feared stimulus with a response incompatible with anxiety. Why it matters: The graded order and the incompatible response are both essential, which is what distinguishes it from simply confronting the fear.
Evaluating therapy outcomes	Definition: Assessment of whether an approach produces improvement beyond what time, expectation and regression toward the average would give. Why it matters: Many people improve without any intervention, which is why an untreated comparison group is essential to any claim about effectiveness.

Frequently asked

What is on each card?

A term on the front. On the back, a definition on all 300, then on 195 the reason it matters. 54 carry a short original scenario rather than an abstract restatement, and 52 name the term this one is most often mixed up with and say what separates them. Each line is labeled, so the back reads as a short structured answer.

How does it handle the disorders and treatment material?

At the level of what the categories are and how they are explained: how classification systems work, the biopsychosocial and diathesis-stress models, what unifies each grouping, and the main theoretical accounts. Treatment appears as schools of approach, such as behavioural, cognitive and humanistic. It does not map symptoms onto a diagnosis and does not compare treatments, because those are judgements for a qualified professional.

Which areas get the most cards?

Biological bases 38 and cognition 38, then research methods and statistics 35, social psychology 33, disorders and treatment 30, sensation and perception 28, learning 28, development 28, motivation and emotion 22, and personality 20. The weighting follows where terminology is densest and most confusable rather than where the reading is longest.

Why so many cards on research methods?

Because method questions are answerable from principle rather than recall, so they repay study more per card than any single content area. The 35 cards cover design, the statistics needed to read a result, measurement quality, and research ethics, including why several classic studies would not be approved today.

How is it organized for studying one area at a time?

Every card carries an area tag and a finer sub-topic tag, across research methods, biological bases, sensation and perception, learning, cognition, motivation and emotion, development, personality, social psychology, and disorders and treatment. Filter by a tag to drill one area, or by the finer tag for a single block such as conditioning, memory, or attribution.

Can I import the whole deck on the free plan?

Yes. Importing a saved deck runs no new AI generation and spends no AI credits, so the free plan imports every card. You can study, edit and delete them afterwards.

Will importing it twice create duplicates?

No. Cards you already have are skipped and only cards added in a revision come through. Including re-imports after deleting it, one official deck can be imported three times per account.

Can I edit the cards after importing?

Yes. Once imported they are your cards: edit either side, delete the ones you already know cold, retag them, or move them into another deck.