- Negative reinforcement
- Removing an aversive stimulus after a behavior to increase it — not the same as punishment, which decreases behavior.
- Classical conditioning
- Pavlovian learning in which a neutral stimulus paired with an unconditioned stimulus comes to elicit a conditioned response.
- Type I error
- Rejecting a true null hypothesis — a false positive. Its probability is alpha.
- Reliability
- The consistency of a measurement across time, items, or raters.
- Object permanence
- The understanding that objects continue to exist when out of view; develops in Piaget's sensorimotor stage.
- Fundamental attribution error
- Overattributing others' behavior to internal traits while underweighting situational causes.
- Action potential
- The brief electrical impulse that travels down a neuron's axon when it fires, triggering neurotransmitter release at the synapse.
- Synapse
- The junction between two neurons where a neurotransmitter is released to communicate a signal.
- Reuptake
- Reabsorption of a neurotransmitter back into the presynaptic neuron after it has acted; SSRIs block serotonin reuptake.
- Neurotransmitter
- A chemical messenger released by a neuron that crosses the synapse to excite or inhibit the next cell.
- Dopamine
- A neurotransmitter for reward, motivation, and movement; excess is linked to psychosis, deficiency to Parkinson's disease.
- Serotonin
- A neurotransmitter regulating mood, sleep, and appetite; low activity is linked to depression and targeted by SSRIs.
- GABA
- The main inhibitory neurotransmitter in the brain; enhanced by benzodiazepines and alcohol, producing calming and sedation.
- Glutamate
- The main excitatory neurotransmitter; central to learning and memory, but excess is excitotoxic.
- Acetylcholine
- A neurotransmitter for memory and muscle activation; markedly depleted in Alzheimer's disease.
- Norepinephrine
- A neurotransmitter for arousal and the fight-or-flight response; implicated in mood and anxiety disorders.
- Broca's area
- A region in the left frontal lobe governing speech production; damage causes nonfluent (expressive) aphasia with intact comprehension.
- Wernicke's area
- A region in the left temporal lobe governing language comprehension; damage causes fluent but meaningless (receptive) aphasia.
- Broca's aphasia
- Nonfluent, effortful, telegraphic speech with relatively preserved comprehension, from damage near Broca's area.
- Wernicke's aphasia
- Fluent but meaningless speech with impaired comprehension, from damage near Wernicke's area.
- Frontal lobe
- Brain region for executive function, planning, judgment, personality, and voluntary movement (motor cortex).
- Occipital lobe
- The brain's posterior region, responsible for visual processing.
- Temporal lobe
- Brain region for hearing, language comprehension, and memory (contains the hippocampus and Wernicke's area).
- Parietal lobe
- Brain region for somatosensory processing, spatial awareness, and integration of sensory information.
- Limbic system
- A set of structures (amygdala, hippocampus, hypothalamus) central to emotion, memory, and motivation.
- Amygdala
- A limbic structure that processes fear and emotional salience; central to threat detection and conditioning.
- Hippocampus
- A limbic structure essential for forming new long-term (declarative) memories.
- Hypothalamus
- A brain structure regulating homeostasis — hunger, thirst, temperature, and the endocrine system via the pituitary.
- Basal ganglia
- Subcortical structures coordinating voluntary movement and habit learning; dysfunction underlies Parkinson's and Huntington's.
- Cerebellum
- A hindbrain structure coordinating balance, posture, and the timing of fine motor movements.
- Brainstem
- The structure (midbrain, pons, medulla) controlling vital functions such as breathing, heart rate, and arousal.
- Sympathetic nervous system
- The branch of the autonomic nervous system that mobilizes the body for fight-or-flight.
- Parasympathetic nervous system
- The branch of the autonomic nervous system that calms the body and conserves energy (rest-and-digest).
- HPA axis
- The hypothalamic-pituitary-adrenal system that governs the stress response, ending in cortisol release from the adrenal glands.
- REM sleep
- Rapid eye movement sleep, marked by vivid dreaming, brain activity resembling wakefulness, and muscle atonia.
- Sleep stages
- Sleep cycles through NREM stages N1–N3 (deepest, slow-wave) and REM, repeating roughly every 90 minutes.
- Behavioral genetics
- The study of how genes and environment jointly influence behavior, using twin, family, and adoption studies.
- Heritability
- The proportion of variation in a trait within a population that is attributable to genetic differences.
- Neuroplasticity
- The brain's ability to reorganize by forming new neural connections in response to learning or injury.
- SSRIs
- Selective serotonin reuptake inhibitors (e.g., fluoxetine, sertraline); first-line drugs for depression and anxiety disorders.
- Antipsychotics
- Medications that reduce psychotic symptoms; typical agents block dopamine D2 receptors, atypicals affect serotonin too.
- Benzodiazepines
- Anxiolytic and sedative drugs (e.g., diazepam, lorazepam) that enhance GABA; risk of dependence with long-term use.
- Lithium
- A first-line mood stabilizer for bipolar disorder; requires blood-level monitoring due to a narrow therapeutic window.
- Tardive dyskinesia
- Involuntary repetitive movements that can result from long-term use of typical antipsychotics.
- Endocrine system
- The system of glands that secrete hormones into the bloodstream to regulate body processes and behavior.
- Unconditioned stimulus (UCS)
- A stimulus that naturally and automatically triggers a response without learning (e.g., food causing salivation).
- Conditioned stimulus (CS)
- A previously neutral stimulus that, after pairing with a UCS, comes to elicit a conditioned response.
- Conditioned response (CR)
- The learned response elicited by a conditioned stimulus after conditioning.
- Extinction
- The weakening of a conditioned response when the CS is repeatedly presented without the UCS.
- Spontaneous recovery
- The reappearance of an extinguished conditioned response after a rest period.
- Stimulus generalization
- Responding to stimuli similar to the conditioned stimulus.
- Stimulus discrimination
- Learning to respond only to the specific conditioned stimulus and not to similar ones.
- Operant conditioning
- Learning in which behavior is shaped by its consequences — reinforcement increases it, punishment decreases it (Skinner).
- Positive reinforcement
- Adding a pleasant stimulus after a behavior to increase its frequency.
- Positive punishment
- Adding an aversive stimulus after a behavior to decrease its frequency.
- Negative punishment
- Removing a pleasant stimulus after a behavior to decrease its frequency.
- Fixed-ratio schedule
- Reinforcement after a set number of responses; produces high response rates with a brief post-reinforcement pause.
- Variable-ratio schedule
- Reinforcement after an unpredictable number of responses; produces the highest, most extinction-resistant responding (e.g., slot machines).
- Fixed-interval schedule
- Reinforcement for the first response after a set time; produces a scalloped pattern of responding.
- Variable-interval schedule
- Reinforcement for the first response after an unpredictable time; produces steady, moderate responding.
- Shaping
- Reinforcing successive approximations toward a target behavior.
- Social learning theory
- Bandura's theory that people learn by observing and imitating others (modeling), as in the Bobo doll study.
- Observational learning
- Acquiring new behaviors by watching others, without direct reinforcement.
- Sensory memory
- The brief, large-capacity store that holds sensory information for a fraction of a second.
- Short-term memory
- A limited store (about 7 ± 2 items) holding information for seconds unless rehearsed.
- Working memory
- Baddeley's model of the limited system that temporarily holds and manipulates information for cognitive tasks.
- Long-term memory
- The relatively permanent, large-capacity store of knowledge and experiences.
- Encoding
- The process of getting information into memory by converting it to a usable form.
- Retrieval
- The process of accessing and bringing stored information into conscious awareness.
- Serial position effect
- The tendency to best recall the first (primacy) and last (recency) items in a list.
- Proactive interference
- When older memories disrupt the recall of newly learned information.
- Retroactive interference
- When newly learned information disrupts the recall of older memories.
- Availability heuristic
- Judging the likelihood of an event by how easily examples come to mind.
- Representativeness heuristic
- Judging probability by how well something matches a prototype, often ignoring base rates.
- James-Lange theory
- The theory that emotion results from our perception of bodily arousal (we feel afraid because we tremble).
- Cannon-Bard theory
- The theory that physiological arousal and the emotional experience occur simultaneously and independently.
- Schachter-Singer theory
- The two-factor theory that emotion requires physiological arousal plus a cognitive label for that arousal.
- Lazarus theory of emotion
- The theory that cognitive appraisal of a situation precedes and determines the emotional response.
- Yerkes-Dodson law
- Performance is best at a moderate level of arousal; too little or too much arousal impairs it.
- Maslow's hierarchy of needs
- A pyramid of needs from physiological and safety up to self-actualization, with lower needs met first.
- Intrinsic motivation
- Engaging in a behavior for its own inherent satisfaction rather than for an external reward.
- Extrinsic motivation
- Engaging in a behavior to obtain an external reward or avoid punishment.
- Overjustification effect
- When an external reward reduces a person's intrinsic motivation for a previously enjoyable activity.
- Actor-observer bias
- Attributing our own behavior to the situation but others' behavior to their character.
- Self-serving bias
- Attributing our successes to internal factors and our failures to external ones.
- Cognitive dissonance
- Festinger's concept: the discomfort of holding inconsistent cognitions, which motivates attitude or behavior change.
- Asch conformity study
- A study showing people conform to a unanimous majority's clearly wrong answer about line lengths.
- Conformity
- Adjusting one's behavior or beliefs to match those of a group.
- Milgram obedience study
- A study showing ordinary people will obey an authority figure's orders to deliver apparently harmful shocks.
- Obedience
- Complying with the direct commands of an authority figure.
- Bystander effect
- The tendency for individuals to be less likely to help when others are present (diffusion of responsibility).
- Diffusion of responsibility
- The reduced sense of personal responsibility to act when others are present.
- Social facilitation
- Improved performance on simple or well-learned tasks in the presence of others.
- Social loafing
- The tendency to exert less effort when working in a group than when working alone.
- Groupthink
- A mode of group decision-making in which the desire for harmony overrides realistic appraisal of alternatives.
- Group polarization
- The tendency for group discussion to strengthen the members' initial attitudes toward an extreme.
- Deindividuation
- A loss of self-awareness and personal responsibility in groups, which can lead to impulsive behavior.
- Elaboration likelihood model
- A model of persuasion with a central route (careful thought) and a peripheral route (superficial cues).
- Central route to persuasion
- Persuasion through careful consideration of the strength of an argument; produces lasting attitude change.
- Peripheral route to persuasion
- Persuasion through superficial cues such as attractiveness or source credibility; less durable change.
- Foot-in-the-door technique
- Gaining compliance with a large request by first securing agreement to a small one.
- Prejudice
- A negative attitude toward members of a group based on their group membership.
- Stereotype
- A generalized belief about the characteristics of a group, applied to its individual members.
- Discrimination
- Unjustified negative behavior toward members of a group.
- In-group bias
- The tendency to favor one's own group over out-groups.
- Just-world hypothesis
- The belief that people get what they deserve, which can lead to blaming victims.
- Mere exposure effect
- The tendency to develop a preference for stimuli simply because they are familiar.
- Attribution theory
- The study of how people explain the causes of behavior, as internal (dispositional) or external (situational).
- Acculturation
- The process of cultural and psychological change from contact between cultures; can be assimilation, integration, separation, or marginalization.
- Individualism
- A cultural orientation emphasizing personal goals, autonomy, and independence.
- Collectivism
- A cultural orientation emphasizing group goals, interdependence, and harmony.
- Multicultural competence
- The knowledge, awareness, and skills to work effectively with clients from diverse cultural backgrounds.
- Cultural humility
- An ongoing, self-reflective stance of openness and respect toward clients' cultural identities and experiences.
- Social identity theory
- The theory that people derive part of their self-concept from membership in social groups.
- Fundamental attribution error (FAE)
- Overattributing others' actions to disposition and underestimating situational influences.
- Piaget's sensorimotor stage
- Birth to about age 2; infants learn through senses and actions, achieving object permanence.
- Piaget's preoperational stage
- Ages 2–7; symbolic thought and language emerge, but children are egocentric and lack conservation.
- Piaget's concrete operational stage
- Ages 7–11; logical thought about concrete events, including conservation and reversibility.
- Piaget's formal operational stage
- Age 11 and up; abstract, hypothetical, and systematic reasoning develop.
- Conservation
- Understanding that quantity stays the same despite changes in shape or arrangement; emerges in the concrete operational stage.
- Egocentrism
- The preoperational child's difficulty taking another person's point of view.
- Assimilation
- Incorporating new experiences into existing mental schemas.
- Accommodation
- Modifying existing schemas to fit new information that does not fit.
- Schema
- A mental framework that organizes and interprets information.
- Trust vs. mistrust
- Erikson's first stage (infancy): developing trust through reliable care; virtue is hope.
- Autonomy vs. shame and doubt
- Erikson's stage (toddlerhood): developing independence; virtue is will.
- Initiative vs. guilt
- Erikson's stage (preschool): asserting purpose through play and planning; virtue is purpose.
- Industry vs. inferiority
- Erikson's stage (school age): developing competence through achievement; virtue is competence.
- Identity vs. role confusion
- Erikson's adolescent stage: forming a coherent sense of self; virtue is fidelity.
- Intimacy vs. isolation
- Erikson's young-adult stage: forming close relationships; virtue is love.
- Generativity vs. stagnation
- Erikson's middle-adult stage: contributing to the next generation; virtue is care.
- Integrity vs. despair
- Erikson's late-life stage: reflecting on a meaningful life; virtue is wisdom.
- Kohlberg preconventional level
- Moral reasoning based on avoiding punishment and gaining rewards (self-interest).
- Kohlberg conventional level
- Moral reasoning based on social approval and maintaining law and order.
- Kohlberg postconventional level
- Moral reasoning based on abstract principles and universal ethics.
- Zone of proximal development
- Vygotsky's range between what a learner can do alone and what they can do with guidance.
- Scaffolding
- Providing temporary support that is gradually withdrawn as a learner becomes more competent.
- Attachment theory
- Bowlby's theory that infants form an emotional bond with caregivers that shapes later relationships.
- Strange Situation
- Ainsworth's procedure classifying infant attachment by reactions to caregiver separation and reunion.
- Secure attachment
- An attachment style marked by distress at separation and comfort on reunion; linked to responsive caregiving.
- Anxious-avoidant attachment
- An insecure style in which the infant shows little distress at separation and avoids the caregiver.
- Anxious-resistant attachment
- An insecure (ambivalent) style with intense distress at separation and difficulty being soothed.
- Disorganized attachment
- An insecure style with contradictory, confused behavior, often linked to frightening caregiving.
- Harlow's monkey studies
- Studies showing infant monkeys prefer a soft surrogate for comfort over a wire one that provides food.
- Temperament
- Biologically based individual differences in emotional and behavioral style, present from early infancy.
- Teratogen
- Any agent (e.g., alcohol, certain drugs, infections) that can cause harm during prenatal development.
- Kubler-Ross stages of grief
- Denial, anger, bargaining, depression, and acceptance — a model of responses to loss.
- Fluid intelligence
- The capacity to reason and solve novel problems; tends to decline with age.
- Crystallized intelligence
- Accumulated knowledge and vocabulary; tends to remain stable or grow with age.
- Authoritative parenting
- A warm, responsive parenting style with firm but reasonable demands; linked to the best child outcomes.
- Theory of mind
- The ability to attribute mental states to oneself and others, typically developing around age 4.
- Test-retest reliability
- The consistency of test scores when the same test is given on two occasions.
- Internal consistency
- The degree to which items on a test measure the same construct (e.g., Cronbach's alpha).
- Cronbach's alpha
- A statistic estimating internal-consistency reliability; values above about 0.70 are generally acceptable.
- Inter-rater reliability
- The degree to which different scorers or observers agree.
- Parallel-forms reliability
- The consistency of scores across two equivalent versions of a test.
- Split-half reliability
- Reliability estimated by correlating scores on two halves of a single test.
- Validity
- The degree to which a test measures what it claims to measure.
- Content validity
- The extent to which a test's items adequately cover the full domain being measured.
- Criterion validity
- The extent to which a test correlates with an outcome (concurrent if measured now, predictive if later).
- Concurrent validity
- Criterion validity established when the test and criterion are measured at the same time.
- Predictive validity
- Criterion validity established when the test predicts a future criterion.
- Construct validity
- Evidence that a test measures the theoretical trait it targets, supported by convergent and discriminant data.
- Convergent validity
- Evidence that a test correlates with measures of the same or related constructs.
- Discriminant validity
- Evidence that a test does not correlate with measures of unrelated constructs.
- Face validity
- Whether a test merely appears, on the surface, to measure what it intends to.
- Reliability-validity relationship
- A test can be reliable without being valid, but it cannot be valid unless it is also reliable.
- Standard error of measurement
- An estimate of how much an observed score would vary across repeated testings; smaller when reliability is higher.
- Norm-referenced test
- A test that interprets a score by comparing it to a representative norm group (e.g., IQ tests).
- Criterion-referenced test
- A test that interprets a score against a fixed standard of mastery rather than a peer group.
- Standardization
- Administering and scoring a test in a uniform way and establishing norms from a representative sample.
- WAIS
- The Wechsler Adult Intelligence Scale, an individually administered IQ test (mean 100, SD 15).
- WISC
- The Wechsler Intelligence Scale for Children, an individually administered IQ test for ages 6–16.
- Stanford-Binet
- An individually administered intelligence test usable across a wide age range.
- MMPI
- The Minnesota Multiphasic Personality Inventory, an objective, empirically keyed personality test with validity scales.
- Validity scales
- MMPI scales (e.g., L, F, K) that detect response distortion such as faking good or faking bad.
- Rorschach
- A projective personality test in which a person interprets inkblots.
- Thematic Apperception Test (TAT)
- A projective test in which a person tells stories about ambiguous pictures.
- Projective test
- An assessment using ambiguous stimuli to reveal underlying motives and conflicts (e.g., Rorschach, TAT).
- Beck Depression Inventory
- A widely used self-report scale measuring the severity of depressive symptoms.
- Normal curve
- A symmetric, bell-shaped distribution in which about 68% of scores fall within 1 SD of the mean and 95% within 2 SD.
- Z-score
- A standardized score expressing how many standard deviations a value is from the mean (mean 0, SD 1).
- T-score
- A standardized score with a mean of 50 and a standard deviation of 10, used on tests like the MMPI.
- Percentile rank
- The percentage of scores in a distribution that fall below a given score.
- Base rate
- The naturally occurring frequency of a condition in a population; ignoring it leads to diagnostic error.
- Sensitivity
- A test's ability to correctly identify those who have a condition (true positive rate).
- Specificity
- A test's ability to correctly identify those who do not have a condition (true negative rate).
- False positive
- A test result indicating a condition is present when it is actually absent.
- False negative
- A test result indicating a condition is absent when it is actually present.
- DSM-5-TR
- The American Psychiatric Association's current diagnostic manual, classifying mental disorders by formal criteria.
- Differential diagnosis
- The process of distinguishing a disorder from others with overlapping symptoms.
- Mental status exam
- A structured assessment of a client's current cognitive and emotional functioning.
- Halstead-Reitan Battery
- A fixed neuropsychological battery assessing brain function across multiple domains.
- Luria-Nebraska Battery
- A standardized neuropsychological battery assessing functions based on Luria's theory.
- Bender-Gestalt Test
- A test of visual-motor integration in which a person copies geometric designs.
- Incremental validity
- The extent to which a new test adds predictive power beyond existing measures.
- Psychodynamic therapy
- Therapy rooted in Freud that explores unconscious conflict, defenses, and transference to produce insight.
- Unconscious
- In psychoanalytic theory, the reservoir of thoughts, wishes, and memories outside conscious awareness.
- Transference
- A client's redirection of feelings about important figures onto the therapist.
- Countertransference
- A therapist's emotional reactions to a client rooted in the therapist's own experiences.
- Free association
- A psychoanalytic technique of saying whatever comes to mind without censorship.
- Defense mechanism
- An unconscious strategy the ego uses to reduce anxiety (e.g., repression, projection, denial).
- Repression
- A defense mechanism that pushes anxiety-provoking thoughts out of conscious awareness.
- Projection
- A defense mechanism that attributes one's own unacceptable impulses to others.
- Displacement
- A defense mechanism that redirects an impulse from a threatening target to a safer one.
- Sublimation
- A defense mechanism that channels unacceptable impulses into socially acceptable activities.
- Reaction formation
- A defense mechanism that expresses the opposite of one's true (anxiety-provoking) feelings.
- Person-centered therapy
- Carl Rogers's humanistic therapy emphasizing empathy, unconditional positive regard, and genuineness.
- Unconditional positive regard
- A Rogerian therapist's nonjudgmental acceptance and warmth toward the client.
- Congruence
- Genuineness — the therapist being authentic and transparent in the relationship (Rogers).
- Systematic desensitization
- Wolpe's behavioral technique pairing relaxation with a graded fear hierarchy to reduce a phobia.
- Exposure therapy
- A behavioral treatment that confronts feared stimuli to extinguish the fear response.
- Flooding
- An exposure technique using prolonged, intense confrontation with the feared stimulus.
- Token economy
- A behavioral system reinforcing desired behaviors with tokens exchangeable for rewards.
- Cognitive behavioral therapy (CBT)
- An evidence-based therapy that restructures distorted thoughts and changes maladaptive behaviors.
- Cognitive distortions
- Beck's systematic errors in thinking (e.g., all-or-nothing thinking, catastrophizing) targeted in CBT.
- REBT
- Ellis's Rational Emotive Behavior Therapy, which disputes irrational beliefs using the ABC model.
- ABC model
- Ellis's framework: an Activating event leads to Beliefs that produce emotional Consequences.
- Structural family therapy
- Minuchin's model that maps and reorganizes family boundaries, subsystems, and hierarchy.
- Dialectical behavior therapy (DBT)
- Linehan's therapy combining acceptance and change skills; effective for borderline personality disorder.
- Acceptance and commitment therapy (ACT)
- Hayes's therapy promoting psychological flexibility through acceptance and values-based action.
- Motivational interviewing
- A client-centered, directive method for resolving ambivalence and strengthening motivation to change.
- Stages of change
- Prochaska's model: precontemplation, contemplation, preparation, action, and maintenance.
- Therapeutic alliance
- The collaborative bond and agreement on goals between therapist and client; a strong predictor of outcome.
- Yalom's therapeutic factors
- Curative elements of group therapy such as universality, instillation of hope, and cohesiveness.
- Universality
- The group-therapy factor of realizing one is not alone in one's problems.
- Evidence-based practice
- Integrating the best available research with clinical expertise and patient values and characteristics.
- Common factors
- Elements shared across therapies (alliance, empathy, hope) that contribute to outcomes.
- Electroconvulsive therapy (ECT)
- A somatic treatment using brief electrical stimulation of the brain; effective for severe, treatment-resistant depression.
- Primary prevention
- Intervention that reduces the incidence of a disorder before it starts, in a whole population.
- Secondary prevention
- Early screening and intervention to reduce the prevalence and duration of a disorder.
- Tertiary prevention
- Reducing the disability and relapse associated with an already-established disorder through rehabilitation.
- Consultation
- Indirect service in which a psychologist helps a consultee improve their work with a third party.
- Clinical supervision
- An evaluative, hierarchical relationship developing a supervisee's competence; the supervisor retains responsibility for client care.
- Gatekeeping
- A supervisor's duty to protect the public by ensuring only competent trainees advance in the profession.
- Systematic desensitization vs. flooding
- Desensitization uses gradual exposure with relaxation; flooding uses prolonged, intense exposure without it.
- Solution-focused therapy
- A brief therapy focusing on clients' strengths and preferred future rather than problem analysis.
- Empirically supported treatment
- A specific intervention shown to be effective for a specific disorder in controlled research.
- Independent variable
- The variable a researcher manipulates to observe its effect.
- Dependent variable
- The variable measured to see whether it is affected by the independent variable.
- Internal validity
- The degree to which a study supports a causal claim, free of confounds; protected by random assignment.
- External validity
- The degree to which findings generalize to other people, settings, and times.
- Confound
- An extraneous variable that varies with the independent variable and offers an alternative explanation.
- Random assignment
- Allocating participants to conditions by chance, which controls confounds and supports causal inference.
- Random sampling
- Selecting participants so each member of the population has an equal chance, supporting generalizability.
- Experimental design
- A study that manipulates an independent variable and uses random assignment to test cause and effect.
- Quasi-experimental design
- A study comparing groups without random assignment, limiting causal conclusions.
- Correlational study
- A study measuring the relationship between variables without manipulation; cannot establish causation.
- History (threat)
- An outside event during a study that affects the outcome, threatening internal validity.
- Maturation (threat)
- Natural changes in participants over time that threaten internal validity.
- Regression to the mean
- The tendency for extreme scores to move toward the average on retesting, mimicking an effect.
- Selection bias
- Systematic differences between groups before treatment, threatening internal validity.
- Attrition
- The loss of participants over a study, which can bias results if dropout is nonrandom.
- Mean
- The arithmetic average of a set of scores.
- Median
- The middle value in an ordered set of scores; robust to outliers.
- Mode
- The most frequently occurring value in a set of scores.
- Standard deviation
- A measure of how spread out scores are around the mean.
- Variance
- The average of the squared deviations from the mean; the square of the standard deviation.
- Positive skew
- A distribution with a long right tail, where the mean is greater than the median.
- Null hypothesis
- The hypothesis of no effect or no difference, which a study tries to reject.
- Alternative hypothesis
- The hypothesis that there is an effect or difference.
- Type II error
- Failing to reject a false null hypothesis — a false negative. Its probability is beta.
- Statistical power
- The probability of correctly rejecting a false null hypothesis (1 − beta); rises with sample size and effect size.
- P-value
- The probability of obtaining results at least as extreme as observed if the null hypothesis were true.
- Alpha level
- The threshold (commonly 0.05) for statistical significance and the probability of a Type I error.
- Correlation coefficient
- A statistic from −1 to +1 describing the strength and direction of a linear relationship.
- Correlation vs. causation
- A correlation shows that variables are related, but does not establish that one causes the other.
- Regression
- A statistical technique that predicts a continuous outcome from one or more predictor variables.
- T-test
- An inferential test comparing the means of two groups.
- ANOVA
- Analysis of variance; an inferential test comparing means across three or more groups.
- Chi-square test
- An inferential test of association between categorical variables.
- Effect size
- A standardized measure of the magnitude of an effect, independent of sample size (e.g., Cohen's d).
- Confidence interval
- A range of values, computed from data, likely to contain the true population parameter.
- Nominal scale
- A measurement scale of unordered categories (e.g., gender, diagnosis).
- Ordinal scale
- A measurement scale with ordered categories but unequal intervals (e.g., rankings).
- Interval scale
- A measurement scale with equal intervals but no true zero (e.g., temperature in Celsius).
- Ratio scale
- A measurement scale with equal intervals and a true zero (e.g., reaction time, weight).
- Meta-analysis
- A statistical method that combines results across many studies to estimate an overall effect.
- APA Ethics Code
- The American Psychological Association's Ethical Principles of Psychologists and Code of Conduct.
- Beneficence and nonmaleficence
- The APA principle of striving to benefit clients and to do no harm.
- Fidelity and responsibility
- The APA principle of establishing trust and being aware of professional responsibilities to the community.
- Integrity
- The APA principle of promoting accuracy, honesty, and truthfulness in psychology.
- Justice (APA principle)
- The APA principle that all persons are entitled to fair access to and benefit from psychology.
- Respect for rights and dignity
- The APA principle of respecting clients' privacy, confidentiality, and self-determination.
- Informed consent
- A client's voluntary agreement to services after disclosure of their nature, risks, fees, and the limits of confidentiality.
- Confidentiality
- The psychologist's duty to protect client information, subject to legal limits.
- Privileged communication
- A legal protection that prevents disclosure of confidential client information in legal proceedings.
- Duty to protect
- The Tarasoff obligation to protect an identifiable victim from a client's serious, imminent threat of violence.
- Tarasoff case
- The court case establishing that therapists may have a duty to protect identifiable third parties from a client's threats.
- Mandated reporting
- The legal duty to report reasonable suspicion of child, elder, or dependent-adult abuse, overriding confidentiality.
- Multiple relationship
- A second role with a client beyond the professional one that risks impaired judgment or exploitation.
- Sexual intimacy with clients
- Prohibited with current clients always; with former clients only after at least 2 years and with strong safeguards.
- Competence
- Practicing only within the boundaries of one's education, training, and experience.
- Boundaries of competence
- The limit of areas in which a psychologist is qualified to provide services.
- Scope of practice
- The range of activities a psychologist is legally and ethically permitted to perform.
- HIPAA
- The federal law setting standards for the privacy and security of protected health information.
- Record keeping
- The ethical and legal duty to create, maintain, and securely store accurate client records.
- Forensic role conflict
- The ethical problem of mixing the treating-therapist role with the objective forensic-evaluator role.
- Child custody evaluation
- A forensic assessment of parenting capacity to inform custody decisions, performed by an impartial evaluator.
- Fitness for duty evaluation
- An assessment of whether a person is psychologically able to perform a job's essential functions.
- Malpractice
- Professional negligence; the four Ds are duty, dereliction of duty, damages, and direct causation.
- Duty (malpractice)
- The professional relationship that creates an obligation of care to the client.
- Licensing
- State-granted authorization to practice psychology, regulated by a licensing board.
- Continuing education
- Ongoing training required to maintain a license and current competence.
- Cultural competence (ethical duty)
- The ethical obligation to provide services sensitive to clients' cultural backgrounds.
- Termination of therapy
- Ethically ending services when the client no longer benefits or is harmed; with notice and referrals.
- Abandonment
- Unethically discontinuing needed services without arranging for the client's continued care.
- Bartering
- Accepting goods or services as payment; allowed only if not clinically contraindicated or exploitative.
- Test security
- The ethical duty to protect the integrity of test materials and answers from improper disclosure.
- Assent
- A minor's or limited-capacity client's agreement to services, obtained alongside a guardian's consent.
- Duty to warn
- Notifying an identifiable potential victim of a client's credible, serious threat, as part of the duty to protect.
- Confidentiality limits
- Situations where confidentiality must yield: duty to protect, mandated reporting, and court orders.
- Privacy
- A client's right to control the disclosure of personal information.
- Dual relationship harm test
- A multiple relationship is unethical when it could reasonably impair objectivity or risk exploitation or harm.
- Aspirational vs. enforceable standards
- The Ethics Code's General Principles are aspirational; the Ethical Standards are enforceable rules.
- Vicarious liability
- A supervisor's legal responsibility for the professional acts of a supervisee.
- Informed consent for recording
- Obtaining a client's permission before audio or video recording a session.
- Conflict between ethics and law
- When the Ethics Code conflicts with law, psychologists clarify the conflict and seek to resolve it responsibly.
- Avoiding harm
- The standard requiring psychologists to take reasonable steps to avoid harming clients and others.
- Boundary crossing vs. violation
- A boundary crossing may be benign or helpful; a boundary violation is harmful or exploitative.
- Confidentiality in group therapy
- Members are asked to maintain confidentiality, but the therapist cannot guarantee other members will.
- Standard of care
- The level of care a reasonably prudent psychologist would provide under similar circumstances.
- Competence in emergencies
- Psychologists may provide services outside their competence in an emergency when no other help is available.
