Vocabulary

Ablation: Surgical removal of brain tissue.
Absolute stability: Consistency in the level or amount of a personality attribute over time.
Absolute threshold: The smallest amount of stimulation needed for detection by a sense.
Acceptance and commitment therapy: A therapeutic approach designed to foster nonjudgmental observation of one’s own mental processes.
Action potential: A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Active person–environment transactions: The interplay between individuals and their contextual circumstances that occurs whenever individuals play a key role in seeking out, selecting, or otherwise manipulating aspects of their environment.
Adaptation: The fact that after people first react to good or bad events, sometimes in a strong way, their feelings and reactions tend to dampen down over time and they return toward their original level of subjective well-being.
Adaptations: Evolved solutions to problems that historically contributed to reproductive success.
Adoption study: A behavior genetic research method that involves comparison of adopted children to their adoptive and biological parents.
Afferent nerves: Nerves that carry messages to the brain or spinal cord.
Age effects: Differences in personality between groups of different ages that are related to maturation and development instead of birth cohort differences.
Agnosia: Loss of the ability to perceive stimuli.
Agnosias: Due to damage of Wernicke’s area. An inability to recognize objects, words, or faces.
Agonists: A drug that increases or enhances a neurotransmitter’s effect.
Agreeableness: A personality trait that reflects a person’s tendency to be compassionate, cooperative, warm, and caring to others. People low in agreeableness tend to be rude, hostile, and to pursue their own interests over those of others.
Alogia: A reduction in the amount of speech and/or increased pausing before the initiation of speech.
Ambulatory assessment: An overarching term to describe methodologies that assess the behavior, physiology, experience, and environments of humans in naturalistic settings.
Anchoring: The bias to be affected by an initial anchor, even if the anchor is arbitrary, and to insufficiently adjust our judgments away from that anchor.
Anecdotal evidence: A piece of biased evidence, usually drawn from personal experience, used to support a conclusion that may or may not be correct.
Anhedonia: Loss of interest or pleasure in activities one previously found enjoyable or rewarding.
Anhedonia/amotivation: A reduction in the drive or ability to take the steps or engage in actions necessary to obtain the potentially positive outcome.
Anosmia: Loss of the ability to smell.
Antagonist: A drug that blocks a neurotransmitter’s effect.
Aphasia: Due to damage of the Broca’s area. An inability to produce or understand words.
Arcuate fasciculus: A fiber tract that connects Wernicke’s and Broca’s speech areas.
Assent: When minor participants are asked to indicate their willingness to participate in a study. This is usually obtained from participants who are at least 7 years old, in addition to parent or guardian consent.
Attachment behavioral system: A motivational system selected over the course of evolution to maintain proximity between a young child and his or her primary attachment figure.
Attachment behaviors: Behaviors and signals that attract the attention of a primary attachment figure and function to prevent separation from that individual or to reestablish proximity to that individual (e.g., crying, clinging).
Attachment figure: Someone who functions as the primary safe haven and secure base for an individual. In childhood, an individual’s attachment figure is often a parent. In adulthood, an individual’s attachment figure is often a romantic partner.
Attachment patterns: (also called “attachment styles” or “attachment orientations”) Individual differences in how securely (vs. insecurely) people think, feel, and behave in attachment relationships.
Attitude: A way of thinking or feeling about a target that is often reflected in a person’s behavior. Examples of attitude targets are individuals, concepts, and groups.
Attraction: A connection between personality attributes and aspects of the environment that occurs because individuals with particular traits are drawn to certain environments.
Attraction: The psychological process of being sexually interested in another person. This can include, for example, physical attraction, first impressions, and dating rituals.
Attributional style: The tendency by which a person infers the cause or meaning of behaviors or events.
Attrition: When a participant drops out, or fails to complete, all parts of a study.
Attrition: A connection between personality attributes and aspects of the environment that occurs because individuals with particular traits drop out from certain environments.
Audition: Ability to process auditory stimuli. Also called hearing.
Auditory canal: Tube running from the outer ear to the middle ear.
Auditory hair cells: Receptors in the cochlea that transduce sound into electrical potentials.
Autobiographical memory: Memory for the events of one’s life.
Automatic thoughts: Thoughts that occur spontaneously; often used to describe problematic thoughts that maintain mental disorders.
Autonomic nervous system: A part of the peripheral nervous system that connects to glands and smooth muscles. Consists of sympathetic and parasympathetic divisions.
Axial plane: See “horizontal plane.”
Axon: Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Basal ganglia: Subcortical structures of the cerebral hemispheres involved in voluntary movement.
Behavioral genetics: The empirical science of how genes and environments combine to generate behavior.
Behaviorism: The study of behavior.
Biases: The systematic and predictable mistakes that influence the judgment of even very talented human beings.
Bidirectional relations: When one variable is likely both cause and consequence of another variable.
Big Five: Five, broad general traits that are included in many prominent models of personality. The five traits are neuroticism (those high on this trait are prone to feeling sad, worried, anxious, and dissatisfied with themselves), extraversion (high scorers are friendly, assertive, outgoing, cheerful, and energetic), openness to experience (those high on this trait are tolerant, intellectually curious, imaginative, and artistic), agreeableness (high scorers are polite, considerate, cooperative, honest, and trusting), and conscientiousness (those high on this trait are responsible, cautious, organized, disciplined, and achievement-oriented).
Binocular advantage: Benefits from having two eyes as opposed to a single eye.
Binocular disparity: Difference is images processed by the left and right eyes.
Binocular vision: Our ability to perceive 3D and depth because of the difference between the images on each of our retinas.
Birth cohort: Individuals born in a particular year or span of time.
Blind to the research hypothesis: When participants in research are not aware of what is being studied.
Blocking: In classical conditioning, the finding that no conditioning occurs to a stimulus if it is combined with a previously conditioned stimulus during conditioning trials. Suggests that information, surprise value, or prediction error is important in conditioning.
“Bottom-up” or external causes of happiness: Situational factors outside the person that influence his or her subjective well-being, such as good and bad events and circumstances such as health and wealth.
Bottom-up processing: Building up to perceptual experience from individual pieces.
Bounded awareness: The systematic ways in which we fail to notice obvious and important information that is available to us.
Bounded ethicality: The systematic ways in which our ethics are limited in ways we are not even aware of ourselves.
Bounded rationality: Model of human behavior that suggests that humans try to make rational decisions but are bounded due to cognitive limitations.
Bounded self-interest: The systematic and predictable ways in which we care about the outcomes of others.
Bounded willpower: The tendency to place greater weight on present concerns rather than future concerns.
Brain stem: The “trunk” of the brain comprised of the medulla, pons, midbrain, and diencephalon.
Broca’s area: An area in the frontal lobe of the left hemisphere. Implicated in language production.
Callosotomy: Surgical procedure in which the corpus callosum is severed (used to control severe epilepsy).
Case study: A thorough study of a patient (or a few patients) with naturally occurring lesions.
Catatonia: Behaviors that seem to reflect a reduction in responsiveness to the external environment. This can include holding unusual postures for long periods of time, failing to respond to verbal or motor prompts from another person, or excessive and seemingly purposeless motor activity.
Categorize: To sort or arrange different items into classes or categories.
Causality: In research, the determination that one variable causes—is responsible for—an effect.
Cause-and-effect: Related to whether we say one variable is causing changes in the other variable, versus other variables that may be related to these two variables.
Cell membrane: A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.
Central route to persuasion: Persuasion that employs direct, relevant, logical messages.
Central sulcus: The major fissure that divides the frontal and the parietal lobes.
Cerebellum: A nervous system structure behind and below the cerebrum. Controls motor movement coordination, balance, equilibrium, and muscle tone.
Cerebellum: The distinctive structure at the back of the brain, Latin for “small brain.”
Cerebral cortex: The outermost gray matter of the cerebrum; the distinctive convoluti characteristic of the mammalian brain.
Cerebral hemispheres: The cerebral cortex, underlying white matter, and subcortical structures.
Cerebrum: Consists of left and right hemispheres that sit at the top of the nervous system and engages in a variety of higher-order functions.
Cerebrum: Usually refers to the cerebral cortex and associated white matter, but in some texts includes the subcortical structures.
Chemical senses: Our ability to process the environmental stimuli of smell and taste.
Chronic stress: Discrete or related problematic events and conditions which persist over time and result in prolonged activation of the biological and/or psychological stress response (e.g., unemployment, ongoing health difficulties, marital discord).
Chutes and Ladders: A numerical board game that seems to be useful for building numerical knowledge.
Cingulate gyrus: A medial cortical portion of the nervous tissue that is a part of the limbic system.
Classical conditioning: The procedure in which an initially neutral stimulus (the conditioned stimulus, or CS) is paired with an unconditioned stimulus (or US). The result is that the conditioned stimulus begins to elicit a conditioned response (CR). Classical conditioning is nowadays considered important as both a behavioral phenomenon and as a method to study simple associative learning. Same as Pavlovian conditioning.
Cochlea: Spiral bone structure in the inner ear containing auditory hair cells.
Cognitive bias modification: Using exercises (e.g., computer games) to change problematic thinking habits.
Cognitive psychology: The study of mental processes.
Cognitive-behavioral therapy (CBT): A family of approaches with the goal of changing the thoughts and behaviors that influence psychopathology.
Cohort effects: When research findings differ for participants of the same age tested at different points in historical time.
Cohort effects: Differences in personality that are related to historical and social factors unique to individuals born in a particular year.
Comorbidity: Describes a state of having more than one psychological or physical disorder at a given time.
Computerized axial tomography: A noninvasive brain-scanning procedure that uses X-ray absorption around the head.
Conceptual Replication: A scientific attempt to copy the scientific hypothesis used in an earlier study in an effort to determine whether the results will generalize to different samples, times, or situations. The same—or similar—results are an indication that the findings are generalizable.
Concrete operations stage: Piagetian stage between ages 7 and 12 when children can think logically about concrete situations but not engage in systematic scientific reasoning.
Conditioned compensatory response: In classical conditioning, a conditioned response that opposes, rather than is the same as, the unconditioned response. It functions to reduce the strength of the unconditioned response. Often seen in conditioning when drugs are used as unconditioned stimuli.
Conditioned response (CR): The response that is elicited by the conditioned stimulus after classical conditioning has taken place.
Conditioned stimulus (CS): An initially neutral stimulus (like a bell, light, or tone) that elicits a conditioned response after it has been associated with an unconditioned stimulus.
Cones: Photoreceptors that operate in lighted environments and can encode fine visual details. There are three different kinds (S or blue, M or green and L or red) that are each sensitive to slightly different types of light. Combined, these three types of cones allow you to have color vision.
Cones: Photoreceptors of the retina sensitive to color. Located primarily in the fovea.
Confederate: An actor working with the researcher. Most often, this individual is used to deceive unsuspecting research participants. Also known as a “stooge.”
Confidence interval: An interval of plausible values for a population parameter; the interval of values within the margin of error of a statistic.
Conformity: Changing one’s attitude or behavior to match a perceived social norm.
Conformity: Changing one’s attitude or behavior to match a perceived social norm.
Confounds: Factors that undermine the ability to draw causal inferences from an experiment.
Conscientiousness: A personality trait that reflects a person’s tendency to be careful, organized, hardworking, and to follow rules.
Consciousness: Awareness of ourselves and our environment.
Conservation problems: Problems pioneered by Piaget in which physical transformation of an object or set of objects changes a perceptually salient dimension but not the quantity that is being asked about.
Consolidation: The process occurring after encoding that is believed to stabilize memory traces.
Context: Stimuli that are in the background whenever learning occurs. For instance, the Skinner box or room in which learning takes place is the classic example of a context. However, “context” can also be provided by internal stimuli, such as the sensory effects of drugs (e.g., being under the influence of alcohol has stimulus properties that provide a context) and mood states (e.g., being happy or sad). It can also be provided by a specific period in time—the passage of time is sometimes said to change the “temporal context.”
Continuous development: Ways in which development occurs in a gradual incremental manner, rather than through sudden jumps.
Continuous distributions: Characteristics can go from low to high, with all different intermediate values possible. One does not simply have the trait or not have it, but can possess varying amounts of it.
Contralateral: Literally “opposite side”; used to refer to the fact that the two hemispheres of the brain process sensory information and motor commands for the opposite side of the body (e.g., the left hemisphere controls the right side of the body).
Contrast: Relative difference in the amount and type of light coming from two nearby locations.
Contrast gain: Process where the sensitivity of your visual system can be tuned to be most sensitive to the levels of contrast that are most prevalent in the environment.
Converging evidence: Similar findings reported from multiple studies using different methods.
Coronal plane: A slice that runs from head to foot; brain slices in this plane are similar to slices of a loaf of bread, with the eyes being the front of the loaf.
Correlation: In statistics, the measure of relatedness of two or more variables.
Correlation: Measures the association between two variables, or how they go together.
Corresponsive principle: The idea that personality traits often become matched with environmental conditions such that an individual’s social context acts to accentuate and reinforce their personality attributes.
Cross-sectional research: A research design used to examine behavior in participants of different ages who are tested at the same point in time.
Cross-sectional study/design: A research design that uses a group of individuals with different ages (and birth cohorts) assessed at a single point in time.
Cue overload principle: The principle stating that the more memories that are associated to a particular retrieval cue, the less effective the cue will be in prompting retrieval of any one memory.
Culture of honor: A culture in which personal or family reputation is especially important.
Cumulative continuity principle: The generalization that personality attributes show increasing stability with age and experience.
Daily Diary method: A methodology where participants complete a questionnaire about their thoughts, feelings, and behavior of the day at the end of the day.
Dark adaptation: Adjustment of eye to low levels of light.
Dark adaptation: Process that allows you to become sensitive to very small levels of light, so that you can actually see in the near-absence of light.
Data (also called observations): In research, information systematically collected for analysis and interpretation.
Day reconstruction method (DRM): A methodology where participants describe their experiences and behavior of a given day retrospectively upon a systematic reconstruction on the following day.
Deductive reasoning: A form of reasoning in which a given premise determines the interpretation of specific observations (e.g., All birds have feathers; since a duck is a bird, it has feathers).
Delusions: False beliefs that are often fixed, hard to change even in the presence of conflicting information, and often culturally influenced in their content.
Dendrite: Part of a neuron that extends away from the cell body and is the main input to the neuron.
Dependent variable: The variable the researcher measures but does not manipulate in an experiment.
Depth perception: The ability to actively perceive the distance from oneself of objects in the environment.
Descriptive norm: The perception of what most people do in a given situation.
Diagnostic criteria: The specific criteria used to determine whether an individual has a specific type of psychiatric disorder. Commonly used diagnostic criteria are included in the Diagnostic and Statistical Manual of Mental Disorder, 5th Edition (DSM-5) and the Internal Classification of Disorders, Version 9 (ICD-9).
Dialectical behavior therapy (DBT): A treatment often used for borderline personality disorder that incorporates both cognitive-behavioral and mindfulness elements.
Dialectical worldview: A perspective in DBT that emphasizes the joint importance of change and acceptance.
Dichotic listening: A task in which different audio streams are presented to each ear. Typically, people are asked to monitor one stream while ignoring the other.
Differential stability: Consistency in the rank-ordering of personality across two or more measurement occasions.
Differential threshold (or difference threshold): The smallest difference needed in order to differentiate two stimuli. (See Just Noticeable Difference (JND))
Diffuse optical imaging (DOI): A neuroimaging technique that infers brain activity by measuring changes in light as it is passed through the skull and surface of the brain.
Diffusion: The force on molecules to move from areas of high concentration to areas of low concentration.
Discontinuous development: Discontinuous development
Discrimination: Discrimination is behavior that advantages or disadvantages people merely based on their group membership.
Discriminative stimulus: In operant conditioning, a stimulus that signals whether the response will be reinforced. It is said to “set the occasion” for the operant response.
Dishabituation: When participants demonstrated increased attention (through looking or listening behavior) to a new stimulus after having been habituated to a different stimulus.
Disorganized behavior: Behavior or dress that is outside the norm for almost all subcultures. This would include odd dress, odd makeup (e.g., lipstick outlining a mouth for 1 inch), or unusual rituals (e.g., repetitive hand gestures).
Disorganized speech: Speech that is difficult to follow, either because answers do not clearly follow questions or because one sentence does not logically follow from another.
Distinctiveness: The principle that unusual events (in a context of similar events) will be recalled and recognized better than uniform (nondistinctive) events.
Distribution: The pattern of variation in data.
Distribution: In statistics, the relative frequency that a particular value occurs for each possible value of a given variable.
Dopamine: A neurotransmitter in the brain that is thought to play an important role in regulating the function of other neurotransmitters.
Dorsal pathway: Pathway of visual processing. The “where” pathway.
Early adversity: Single or multiple acute or chronic stressful events, which may be biological or psychological in nature (e.g., poverty, abuse, childhood illness or injury), occurring during childhood and resulting in a biological and/or psychological stress response.
Ecological momentary assessment: An overarching term to describe methodologies that repeatedly sample participants’ real-world experiences, behavior, and physiology in real time.
Ecological validity: The degree to which a study finding has been obtained under conditions that are typical for what happens in everyday life.
Ectoderm: The outermost layer of a developing fetus.
Efferent nerves: Nerves that carry messages from the brain to glands and organs in the periphery.
Ego defenses: Mental strategies, rooted in the ego, that we use to manage anxiety when we feel threatened (some examples include repression, denial, sublimation, and reaction formation).
Electroencephalography: A technique that is used to measure gross electrical activity of the brain by placing electrodes on the scalp.
Electroencephalography (EEG): A neuroimaging technique that measures electrical brain activity via multiple electrodes on the scalp.
Electronically activated recorder, or EAR: A methodology where participants wear a small, portable audio recorder that intermittently records snippets of ambient sounds around them.
Electrostatic pressure: The force on two ions with similar charge to repel each other; the force of two ions with opposite charge to attract to one another.
Elicited imitation: A behavioral method used to examine recall memory in infants and young children.
Empirical: Concerned with observation and/or the ability to verify a claim.
Empirical methods: Approaches to inquiry that are tied to actual measurement and observation.
Empiricism: The belief that knowledge comes from experience.
Encoding: The initial experience of perceiving and learning events.
Encoding specificity principle: The hypothesis that a retrieval cue will be effective to the extent that information encoded from the cue overlaps or matches information in the engram or memory trace.
Engrams: A term indicating the change in the nervous system representing an event; also, memory trace.
Enzyme: A protein produced by a living organism that allows or helps a chemical reaction to occur.
Enzyme induction: Process through which a drug can enhance the production of an enzyme.
Episodic memory: Memory for events in a particular time and place.
Episodic memory: The ability to learn and retrieve new information or episodes in one’s life.
Error management theory (EMT): A theory of selection under conditions of uncertainty in which recurrent cost asymmetries of judgment or inference favor the evolution of adaptive cognitive biases that function to minimize the more costly errors.
Ethics: Professional guidelines that offer researchers a template for making decisions that protect research participants from potential harm and that help steer scientists away from conflicts of interest or other situations that might compromise the integrity of their research.
Eugenics: The practice of selective breeding to promote desired traits.
Event-related potentials: A physiological measure of large electrical change in the brain produced by sensory stimulation or motor responses.
Event-related potentials (ERP): The recording of participant brain activity using a stretchy cap with small electrodes or sensors as participants engage in a particular task (commonly viewing photographs or listening to auditory stimuli).
Evocative person–environment transactions: The interplay between individuals and their contextual circumstances that occurs whenever attributes of the individual draw out particular responses from others in their environment.
Evolution: Change over time. Is the definition changing?
Exact Replication (also called Direct Replication): A scientific attempt to exactly copy the scientific methods used in an earlier study in an effort to determine whether the results are consistent. The same—or similar—results are an indication that the findings are accurate.
Excitatory postsynaptic potentials: A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.
Experience-sampling method: A methodology where participants report on their momentary thoughts, feelings, and behaviors at different points in time over the course of a day.
Experimenter expectations: When the experimenter’s expectations influence the outcome of a study.
Exposure therapy: A form of intervention in which the patient engages with a problematic (usually feared) situation without avoidance or escape.
External validity: The degree to which a finding generalizes from the specific sample and context of a study to some larger population and broader settings.
Extinction: Decrease in the strength of a learned behavior that occurs when the conditioned stimulus is presented without the unconditioned stimulus (in classical conditioning) or when the behavior is no longer reinforced (in instrumental conditioning). The term describes both the procedure (the US or reinforcer is no longer presented) as well as the result of the procedure (the learned response declines). Behaviors that have been reduced in strength through extinction are said to be “extinguished.”
Extraversion: A personality trait that reflects a person’s tendency to be sociable, outgoing, active, and assertive.
Facets: Broad personality traits can be broken down into narrower facets or aspects of the trait. For example, extraversion has several facets, such as sociability, dominance, risk-taking and so forth.
Fact: Objective information about the world.
Factor analysis: A statistical technique for grouping similar things together according to how highly they are associated.
False memories: Memory for an event that never actually occurred, implanted by experimental manipulation or other means.
Falsified data (faked data): Data that are fabricated, or made up, by researchers intentionally trying to pass off research results that are inaccurate. This is a serious ethical breach and can even be a criminal offense.
Falsify: In science, the ability of a claim to be tested and—possibly—refuted; a defining feature of science.
Fear conditioning: A type of classical or Pavlovian conditioning in which the conditioned stimulus (CS) is associated with an aversive unconditioned stimulus (US), such as a foot shock. As a consequence of learning, the CS comes to evoke fear. The phenomenon is thought to be involved in the development of anxiety disorders in humans.
Five-Factor Model: (also called the Big Five) The Five-Factor Model is a widely accepted model of personality traits. Advocates of the model believe that much of the variability in people’s thoughts, feelings, and behaviors can be summarized with five broad traits. These five traits are Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism.
Fixed action patterns (FAPs): Sequences of behavior that occur in exactly the same fashion, in exactly the same order, every time they are elicited.
Flashbulb memory: Vivid personal memories of receiving the news of some momentous (and usually emotional) event.
Flashbulb memory: A highly detailed and vivid memory of an emotionally significant event.
Flat affect: A reduction in the display of emotions through facial expressions, gestures, and speech intonation.
Flavor: The combination of smell and taste.
Foils: Any member of a lineup (whether live or photograph) other than the suspect.
Foot in the door: Obtaining a small, initial commitment.
Forebrain: A part of the nervous system that contains the cerebral hemispheres, thalamus, and hypothalamus.
Formal operations stage: Piagetian stage starting at age 12 years and continuing for the rest of life, in which adolescents may gain the reasoning powers of educated adults.
Fornix: (plural form, fornices) A nerve fiber tract that connects the hippocampus to mammillary bodies.
Framing: The bias to be systematically affected by the way in which information is presented, while holding the objective information constant.
Free association: In psychodynamic therapy, a process in which the patient reports all thoughts that come to mind without censorship, and these thoughts are interpreted by the therapist.
Frontal lobe: The front most (anterior) part of the cerebrum; anterior to the central sulcus and responsible for motor output and planning, language, judgment, and decision-making.
Frontal lobe: The most forward region (close to forehead) of the cerebral hemispheres.
Full-cycle psychology: A scientific approach whereby researchers start with an observational field study to identify an effect in the real world, follow up with laboratory experimentation to verify the effect and isolate the causal mechanisms, and return to field research to corroborate their experimental findings.
Functional capacity: The ability to engage in self-care (cook, clean, bathe), work, attend school, and/or engage in social relationships.
Functional magnetic resonance imaging: (or fMRI) A noninvasive brain-imaging technique that registers changes in blood flow in the brain during a given task (also see magnetic resonance imaging).
Functional magnetic resonance imaging (fMRI): Functional magnetic resonance imaging (fMRI): A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood.
Functionalism: A school of American psychology that focused on the utility of consciousness.
Fundamental attribution error: The tendency to emphasize another person’s personality traits when describing that person’s motives and behaviors and overlooking the influence of situational factors.
Gene Selection Theory: The modern theory of evolution by selection by which differential gene replication is the defining process of evolutionary change.
Generalizability: Related to whether the results from the sample can be generalized to a larger population.
Generalize: Generalizing, in science, refers to the ability to arrive at broad conclusions based on a smaller sample of observations. For these conclusions to be true the sample should accurately represent the larger population from which it is drawn.
Generalize: In research, the degree to which one can extend conclusions drawn from the findings of a study to other groups or situations not included in the study.
Gestalt psychology: An attempt to study the unity of experience.
Globus pallidus: A nucleus of the basal ganglia.
Goal-directed behavior: Instrumental behavior that is influenced by the animal’s knowledge of the association between the behavior and its consequence and the current value of the consequence. Sensitive to the reinforcer devaluation effect.
Gradually escalating commitments: A pattern of small, progressively escalating demands is less likely to be rejected than a single large demand made all at once.
Grandiosity: Inflated self-esteem or an exaggerated sense of self-importance and self-worth (e.g., believing one has special powers or superior abilities).
Gray matter: The outer grayish regions of the brain comprised of the neurons’ cell bodies.
Gray matter: Composes the bark or the cortex of the cerebrum and consists of the cell bodies of the neurons (see also white matter).
Group level: A focus on summary statistics that apply to aggregates of individuals when studying personality development. An example is considering whether the average score of a group of 50 year olds is higher than the average score of a group of 21 year olds when considering a trait like conscientiousness.
Gustation: Ability to process gustatory stimuli. Also called taste.
Gyri: (plural) Folds between sulci in the cortex.
Gyrus: A fold between sulci in the cortex.
Gyrus: (plural form, gyri) A bulge that is raised between or among fissures of the convoluted brain.
Habit: Instrumental behavior that occurs automatically in the presence of a stimulus and is no longer influenced by the animal’s knowledge of the value of the reinforcer. Insensitive to the reinforcer devaluation effect.
Habituation: When participants demonstrated decreased attention (through looking or listening behavior) to repeatedly-presented stimuli.
Hallucinations: Perceptual experiences that occur even when there is no stimulus in the outside world generating the experiences. They can be auditory, visual, olfactory (smell), gustatory (taste), or somatic (touch).
Happiness: The popular word for subjective well-being. Scientists sometimes avoid using this term because it can refer to different things, such as feeling good, being satisfied, or even the causes of high subjective well-being.
Heritability coefficient: An easily misinterpreted statistical construct that purports to measure the role of genetics in the explanation of differences among individuals.
Heterotypic stability: Consistency in the underlying psychological attribute across development regardless of any changes in how the attribute is expressed at different ages.
Heuristics: Mental shortcuts that enable people to make decisions and solve problems quickly and efficiently.
Heuristics: cognitive (or thinking) strategies that simplify decision making by using mental short-cuts
HEXACO model: The HEXACO model is an alternative to the Five-Factor Model. The HEXACO model includes six traits, five of which are variants of the traits included in the Big Five (Emotionality [E], Extraversion [X], Agreeableness [A], Conscientiousness [C], and Openness [O]). The sixth factor, Honesty-Humility [H], is unique to this model.
High-stakes testing: Settings in which test scores are used to make important decisions about individuals. For example, test scores may be used to determine which individuals are admitted into a college or graduate school, or who should be hired for a job. Tests also are used in forensic settings to help determine whether a person is competent to stand trial or fits the legal definition of sanity.
Hippocampus: (plural form, hippocampi) A nucleus inside (medial) the temporal lobe implicated in learning and memory.
Homo habilis: A human ancestor, handy man, that lived two million years ago.
Homo sapiens: Modern man, the only surviving form of the genus Homo.
Homotypic stability: Consistency of the exact same thoughts, feelings, and behaviors across development.
Honeymoon effect: The tendency for newly married individuals to rate their spouses in an unrealistically positive manner. This represents a specific manifestation of the letter of recommendation effect when applied to ratings made by current romantic partners. Moreover, it illustrates the very important role played by relationship satisfaction in ratings made by romantic partners: As marital satisfaction declines (i.e., when the “honeymoon is over”), this effect disappears.
Horizontal plane: A slice that runs horizontally through a standing person (i.e., parallel to the floor); slices of brain in this plane divide the top and bottom parts of the brain; this plane is similar to slicing a hamburger bun.
Hostile attribution bias: The tendency of some individuals to interpret ambiguous social cues and interactions as examples of aggressiveness, disrespect, or antagonism.
Hypersomnia: Excessive daytime sleepiness, including difficulty staying awake or napping, or prolonged sleep episodes.
Hypothalamus: Part of the diencephalon. Regulates biological drives with pituitary gland.
Hypotheses: A logical idea that can be tested.
Hypothesis: A possible explanation that can be tested through research.
Hypothesis: A tentative explanation that is subject to testing.
Immunocytochemistry: A method of staining tissue including the brain, using antibodies.
Implicit motives: These are goals that are important to a person, but that he/she cannot consciously express. Because the individual cannot verbalize these goals directly, they cannot be easily assessed via self-report. However, they can be measured using projective devices such as the Thematic Apperception Test (TAT).
Inattentional blindness: The failure to notice a fully visible, but unexpected, object or event when attention is devoted to something else.
Inattentional deafness: The auditory analog of inattentional blindness. People fail to notice an unexpected sound or voice when attention is devoted to other aspects of a scene.
Independent: Two characteristics or traits are separate from one another-- a person can be high on one and low on the other, or vice-versa. Some correlated traits are relatively independent in that although there is a tendency for a person high on one to also be high on the other, this is not always the case.
Independent variable: The variable the researcher manipulates and controls in an experiment.
Individual differences: Ways in which people differ in terms of their behavior, emotion, cognition, and development.
Individual level: A focus on individual level statistics that reflect whether individuals show stability or change when studying personality development. An example is evaluating how many individuals increased in conscientiousness versus how many decreased in conscientiousness when considering the transition from adolescence to adulthood.
Induction: To draw general conclusions from specific observations.
Inductive reasoning: A form of reasoning in which a general conclusion is inferred from a set of observations (e.g., noting that “the driver in that car was texting; he just cut me off then ran a red light!” (a specific observation), which leads to the general conclusion that texting while driving is dangerous).
Information processing theories: Theories that focus on describing the cognitive processes that underlie thinking at any one age and cognitive growth over time.
Informational influence: Conformity that results from a concern to act in a socially approved manner as determined by how others act.
Informed consent: The process of getting permission from adults for themselves and their children to take part in research.
Inhibitory postsynaptic potentials: A hyperpolarizing postsynaptic current that causes the membrane potential to become more negative and move away from the threshold of excitation.
Institutional Review Boards (IRBs): A committee that reviews and approves research procedures involving human participants and animal subjects to ensure that the research is conducted in accordance with federal, institutional, and ethical guidelines.
Instrumental conditioning: Process in which animals learn about the relationship between their behaviors and their consequences. Also known as operant conditioning.
Integrative or eclectic psychotherapy: Also called integrative psychotherapy, this term refers to approaches combining multiple orientations (e.g., CBT with psychoanalytic elements).
Integrative or eclectic psychotherapy: Also called integrative psychotherapy, this term refers to approaches combining multiple orientations (e.g., CBT with psychoanalytic elements).
Internal validity: The degree to which a cause-effect relationship between two variables has been unambiguously established.
Intersexual selection: A process of sexual selection by which evolution (change) occurs as a consequences of the mate preferences of one sex exerting selection pressure on members of the opposite sex.
Interview techniques: A research method in which participants are asked to report on their experiences using language, commonly by engaging in conversation with a researcher (participants may also be asked to record their responses in writing).
Intrasexual competition: A process of sexual selection by which members of one sex compete with each other, and the victors gain preferential mating access to members of the opposite sex.
Introspection: A method of focusing on internal processes.
Involuntary or obligatory responses: Behaviors in which individuals engage that do not require much conscious thought or effort.
Ion channels: Proteins that span the cell membrane, forming channels that specific ions can flow through between the intracellular and extracellular space.
Ionotropic receptor: Ion channel that opens to allow ions to permeate the cell membrane under specific conditions, such as the presence of a neurotransmitter or a specific membrane potential.
Just noticeable difference (JND): The smallest difference needed in order to differentiate two stimuli. (see Differential Threshold)
Lateral geniculate nucleus: (or LGN) A nucleus in the thalamus that is innervated by the optic nerves and sends signals to the visual cortex in the occipital lobe.
Lateral inhibition: A signal produced by a neuron aimed at suppressing the response of nearby neurons.
Lateral sulcus: The major fissure that delineates the temporal lobe below the frontal and the parietal lobes.
Lateralized: To the side; used to refer to the fact that specific functions may reside primarily in one hemisphere or the other (e.g., for the majority individuals, the left hemisphere is most responsible for language).
Law of effect: The idea that instrumental or operant responses are influenced by their effects. Responses that are followed by a pleasant state of affairs will be strengthened and those that are followed by discomfort will be weakened. Nowadays, the term refers to the idea that operant or instrumental behaviors are lawfully controlled by their consequences.
Lesion: A region in the brain that suffered damage through injury, disease, or medical intervention.
Lesion studies: A surgical method in which a part of the animal brain is removed to study its effects on behavior or function.
Letter of recommendation effect: The general tendency for informants in personality studies to rate others in an unrealistically positive manner. This tendency is due a pervasive bias in personality assessment: In the large majority of published studies, informants are individuals who like the person they are rating (e.g., they often are friends or family members) and, therefore, are motivated to depict them in a socially desirable way. The term reflects a similar tendency for academic letters of recommendation to be overly positive and to present the referent in an unrealistically desirable manner.
Levels of analysis: Complementary views for analyzing and understanding a phenomenon.
Levels of analysis: In science, there are complementary understandings and explanations of phenomena.
Lexical hypothesis: The lexical hypothesis is the idea that the most important differences between people will be encoded in the language that we use to describe people. Therefore, if we want to know which personality traits are most important, we can look to the language that people use to describe themselves and others.
Life satisfaction: A person reflects on their life and judges to what degree it is going well, by whatever standards that person thinks are most important for a good life.
Light adaptation: Adjustment of eye to high levels of light.
Limbic system: Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Limbic system: A loosely defined network of nuclei in the brain involved with learning and emotion.
Linguistic inquiry and word count: A quantitative text analysis methodology that automatically extracts grammatical and psychological information from a text by counting word frequencies.
Lived day analysis: A methodology where a research team follows an individual around with a video camera to objectively document a person’s daily life as it is lived.
Longitudinal research: A research design used to examine behavior in the same participants over short (months) or long (decades) periods of time.
Longitudinal study: A study that follows the same group of individuals over time.
Longitudinal study/design: A research design that follows the same group of individuals at multiple time points.
Magnetic resonance imaging: Or MRI is a brain imaging noninvasive technique that uses magnetic energy to generate brain images (also see fMRI).
Magnetic resonance imaging: A set of techniques that uses strong magnets to measure either the structure of the brain (e.g., gray matter and white matter) or how the brain functions when a person performs cognitive tasks (e.g., working memory or episodic memory) or other types of tasks.
Magnification factor: Cortical space projected by an area of sensory input (e.g., mm of cortex per degree of visual field).
Manipulation: A connection between personality attributes and aspects of the environment that occurs whenever individuals with particular traits actively shape their environments.
Margin of error: The expected amount of random variation in a statistic; often defined for 95% confidence level.
Maturity principle: The generalization that personality attributes associated with the successful fulfillment of adult roles increase with age and experience.
Mechanoreceptors: Mechanical sensory receptors in the skin that response to tactile stimulation.
Medulla oblongata: An area just above the spinal cord that processes breathing, digestion, heart and blood vessel function, swallowing, and sneezing.
Memory traces: A term indicating the change in the nervous system representing an event.
Metabolism: Breakdown of substances.
Metabolite: A substance necessary for a living organism to maintain life.
Mindfulness: A process that reflects a nonjudgmental, yet attentive, mental state.
Mindfulness-based therapy: A form of psychotherapy grounded in mindfulness theory and practice, often involving meditation, yoga, body scan, and other features of mindfulness exercises.
Misinformation effect: A memory error caused by exposure to incorrect information between the original event (e.g., a crime) and later memory test (e.g., an interview, lineup, or day in court).
Misinformation effect: When erroneous information occurring after an event is remembered as having been part of the original event.
Mnemonic devices: A strategy for remembering large amounts of information, usually involving imaging events occurring on a journey or with some other set of memorized cues.
Mock witnesses: A research subject who plays the part of a witness in a study.
Motor control: The use of thinking to direct muscles and limbs to perform a desired action.
Motor cortex: Region of the frontal lobe responsible for voluntary movement; the motor cortex has a contralateral representation of the human body.
Multimodal perception: The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
Myelin: Fatty tissue, produced by glial cells (see module, “Neurons”) that insulates the axons of the neurons; myelin is necessary for normal conduction of electrical impulses among neurons.
Myelin sheath: Substance around the axon of a neuron that serves as insulation to allow the action potential to conduct rapidly toward the terminal buttons.
Natural selection: Differential reproductive success as a consequence of differences in heritable attributes.
Nature: The genes that children bring with them to life and that influence all aspects of their development.
Need to belong: A strong natural impulse in humans to form social connections and to be accepted by others.
Negative feelings: Undesirable and unpleasant feelings that people tend to avoid if they can. Moods and emotions such as depression, anger, and worry are examples.
Neural crest: A set of primordial neurons that migrate outside the neural tube and give rise to sensory and autonomic neurons in the peripheral nervous system.
Neural impulse: An electro-chemical signal that enables neurons to communicate.
Neural induction: A process that causes the formation of the neural tube.
Neuroblasts: Brain progenitor cells that asymmetrically divide into other neuroblasts or nerve cells.
Neurodevelopmental: Processes that influence how the brain develops either in utero or as the child is growing up.
Neuroepithelium: The lining of the neural tube.
Neuropsychoanalysis: An integrative, interdisciplinary domain of inquiry seeking to integrate psychoanalytic and neuropsychological ideas and findings to enhance both areas of inquiry (you can learn more by visiting the webpage of the International Neuropsychoanalysis Society at http://www.neuropsa.org.uk/).
Neuroticism: A personality trait that reflects the tendency to be interpersonally sensitive and the tendency to experience negative emotions like anxiety, fear, sadness, and anger.
Neurotransmitter: A chemical substance produced by a neuron that is used for communication between neurons.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Nociception: Our ability to sense pain.
Nomenclature: Naming conventions.
Normative influence: Conformity that results from a concern for what other people think of us.
Nucleus: Collection of nerve cells found in the brain which typically serve a specific function.
Null-hypothesis significance testing (NHST): In statistics, a test created to determine the chances that an alternative hypothesis would produce a result as extreme as the one observed if the null hypothesis were actually true.
Numerical magnitudes: The sizes of numbers.
Nurture: The environments, starting with the womb, that influence all aspects of children’s development.
Obedience: Responding to an order or command from a person in a position of authority.
Obedience: Responding to an order or command from a person in a position of authority.
Object permanence: The understanding that objects continue to exist even when they cannot be directly observed (e.g., that a pen continues to exist even when it is hidden under a piece of paper).
Object permanence task: The Piagetian task in which infants below about 9 months of age fail to search for an object that is removed from their sight and, if not allowed to search immediately for the object, act as if they do not know that it continues to exist.
Object relations theory: A modern offshoot of the psychodynamic perspective, this theory contends that personality can be understood as reflecting mental images of significant figures (especially the parents) that we form early in life in response to interactions taking place within the family; these mental images serve as templates (or “scripts”) for later interpersonal relationships.
Objective: Being free of personal bias.
Observational learning: Learning by observing the behavior of others.
Observational learning: Learning by observing the behavior of others.
Occipital lobe: The back part of the cerebrum, which houses the visual areas.
Occipital lobe: The back most (posterior) part of the cerebrum; involved in vision.
Odorants: Chemicals transduced by olfactory receptors.
Olfaction: Ability to process olfactory stimuli. Also called smell.
Olfactory epithelium: Organ containing olfactory receptors.
Openness to Experience: A personality trait that reflects a person’s tendency to seek out and to appreciate new things, including thoughts, feelings, values, and experiences.
Operant: A behavior that is controlled by its consequences. The simplest example is the rat’s lever-pressing, which is controlled by the presentation of the reinforcer.
Operant conditioning: See instrumental conditioning.
Operational definitions: How researchers specifically measure a concept.
Opponent Process Theory: Theory of color vision that assumes there are four different basic colors, organized into two pairs (red/green and blue/yellow) and proposes that colors in the world are encoded in terms of the opponency (or difference) between the colors in each pair. There is an additional black/white pair responsible for coding light contrast.
Opponent-process theory: Theory proposing color vision as influenced by cells responsive to pairs of colors.
Ossicles: A collection of three small bones in the middle ear that vibrate against the tympanic membrane.
Overconfident: The bias to have greater confidence in your judgment than is warranted based on a rational assessment.
Parameter: A numerical result summarizing a population (e.g., mean, proportion).
Parasympathetic nervous system: A division of the autonomic nervous system that is slower than its counterpart—that is, the sympathetic nervous system—and works in opposition to it. Generally engaged in “rest and digest” functions.
Parietal lobe: The part of the cerebrum between the frontal and occipital lobes; involved in bodily sensations, visual attention, and integrating the senses.
Parietal lobe: An area of the cerebrum just behind the central sulcus that is engaged with somatosensory and gustatory sensation.
Participant demand: When participants behave in a way that they think the experimenter wants them to behave.
Pavlovian conditioning: See classical conditioning.
Perception: The psychological process of interpreting sensory information.
Peripheral route to persuasion: Persuasion that relies on superficial cues that have little to do with logic.
Personality: Enduring predispositions that characterize a person, such as styles of thought, feelings and behavior.
Personality traits: Enduring dispositions in behavior that show differences across individuals, and which tend to characterize the person across varying types of situations.
Person-centered therapy: A therapeutic approach focused on creating a supportive environment for self-discovery.
Person–environment transactions: The interplay between individuals and their contextual circumstances that ends up shaping both personality and the environment.
Person-situation debate: The person-situation debate is a historical debate about the relative power of personality traits as compared to situational influences on behavior. The situationist critique, which started the person-situation debate, suggested that people overestimate the extent to which personality traits are consistent across situations.
Phantom limb: The perception that a missing limb still exists.
Phantom limb pain: Pain in a limb that no longer exists.
Pharmacokinetics: The action of a drug through the body, including absorption, distribution, metabolism, and excretion.
Phonemic awareness: Awareness of the component sounds within words.
Photo spreads: A selection of normally small photographs of faces given to a witness for the purpose of identifying a perpetrator.
Photoactivation: A photochemical reaction that occurs when light hits photoreceptors, producing a neural signal.
Phrenology: A now-discredited field of brain study, popular in the first half of the 19th century that correlated bumps and indentations of the skull with specific functions of the brain.
Piaget’s theory: Theory that development occurs through a sequence of discontinuous stages: the sensorimotor, preoperational, concrete operational, and formal operational stages.
Pinna: Outermost portion of the ear.
Placebo effect: When receiving special treatment or something new affects human behavior.
Polypharmacy: The use of many medications.
Pons: A bridge that connects the cerebral cortex with the medulla, and reciprocally transfers information back and forth between the brain and the spinal cord.
Population: A larger collection of individuals that we would like to generalize our results to.
Population: In research, all the people belonging to a particular group (e.g., the population of left handed people).
Positive feelings: Desirable and pleasant feelings. Moods and emotions such as enjoyment and love are examples.
Positron Emission Tomography: (or PET) An invasive procedure that captures brain images with positron emissions from the brain after the individual has been injected with radio-labeled isotopes.
Positron emission tomography: A technique that uses radio-labelled ligands to measure the distribution of different neurotransmitter receptors in the brain or to measure how much of a certain type of neurotransmitter is released when a person is given a specific type of drug or does a particularly cognitive task.
Positron emission tomography (PET): A neuroimaging technique that measures brain activity by detecting the presence of a radioactive substance in the brain that is initially injected into the bloodstream and then pulled in by active brain tissue.
Practice effect: When participants get better at a task over time by “practicing” it through repeated assessments instead of due to actual developmental change (practice effects can be particularly problematic in longitudinal and sequential research designs).
Practitioner-Scholar Model: A model of training of professional psychologists that emphasizes clinical practice.
Prediction error: When the outcome of a conditioning trial is different from that which is predicted by the conditioned stimuli that are present on the trial (i.e., when the US is surprising). Prediction error is necessary to create Pavlovian conditioning (and associative learning generally). As learning occurs over repeated conditioning trials, the conditioned stimulus increasingly predicts the unconditioned stimulus, and prediction error declines. Conditioning works to correct or reduce prediction error.
Prejudice: An evaluation or emotion toward people based merely on their group membership.
Preoperational reasoning stage: Period within Piagetian theory from age 2 to 7 years, in which children can represent objects through drawing and language but cannot solve logical reasoning problems, such as the conservation problems.
Preparedness: The idea that an organism’s evolutionary history can make it easy to learn a particular association. Because of preparedness, you are more likely to associate the taste of tequila, and not the circumstances surrounding drinking it, with getting sick. Similarly, humans are more likely to associate images of spiders and snakes than flowers and mushrooms with aversive outcomes like shocks.
Primacy of the Unconscious: The hypothesis—supported by contemporary empirical research—that the vast majority of mental activity takes place outside conscious awareness.
Primary auditory cortex: Area of the cortex involved in processing auditory stimuli.
Primary Motor Cortex: A strip of cortex just in front of the central sulcus that is involved with motor control.
Primary Somatosensory Cortex: A strip of cerebral tissue just behind the central sulcus engaged in sensory reception of bodily sensations.
Primary somatosensory cortex: Area of the cortex involved in processing somatosensory stimuli.
Primary visual cortex: Area of the cortex involved in processing visual stimuli.
Primary visual cortex (V1): Brain region located in the occipital cortex (toward the back of the head) responsible for processing basic visual information like the detection, thickness, and orientation of simple lines, color, and small-scale motion.
Priming: The process by which exposing people to one stimulus makes certain thoughts, feelings or behaviors more salient.
Principle of inverse effectiveness: The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large. However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.
Probability: A measure of the degree of certainty of the occurrence of an event.
Probability values: In statistics, the established threshold for determining whether a given value occurs by chance.
Processing speed: The speed with which an individual can perceive auditory or visual information and respond to it.
Projective hypothesis: The theory that when people are confronted with ambiguous stimuli (that is, stimuli that can be interpreted in more than one way), their responses will be influenced by their unconscious thoughts, needs, wishes, and impulses. This, in turn, is based on the Freudian notion of projection, which is the idea that people attribute their own undesirable/unacceptable characteristics to other people or objects.
Pseudoscience: Beliefs or practices that are presented as being scientific, or which are mistaken for being scientific, but which are not scientific (e.g., astrology, the use of celestial bodies to make predictions about human behaviors, and which presents itself as founded in astronomy, the actual scientific study of celestial objects. Astrology is a pseudoscience unable to be falsified, whereas astronomy is a legitimate scientific discipline).
Psychic causality: The assumption that nothing in mental life happens by chance—that there is no such thing as a “random” thought or feeling.
Psychoactive drugs: A drug that changes mood or the way someone feels.
Psychoanalytic therapy: Sigmund Freud’s therapeutic approach focusing on resolving unconscious conflicts.
Psychodynamic therapy: Treatment applying psychoanalytic principles in a briefer, more individualized format.
Psychological adaptations: Mechanisms of the mind that evolved to solve specific problems of survival or reproduction; conceptualized as information processing devices.
Psychological reactance: A reaction to people, rules, requirements, or offerings that are perceived to limit freedoms.
Psychomotor agitation: Increased motor activity associated with restlessness, including physical actions (e.g., fidgeting, pacing, feet tapping, handwringing).
Psychomotor retardation: A slowing of physical activities in which routine activities (e.g., eating, brushing teeth) are performed in an unusually slow manner.
Psychopathology: Illnesses or disorders that involve psychological or psychiatric symptoms.
Psychophysics: Study of the relationships between physical stimuli and the perception of those stimuli.
Psychophysiological responses: Recording of biological measures (such as heart rate and hormone levels) and neurological responses (such as brain activity) that may be associated with observable behaviors.
Psychosexual stage model: Probably the most controversial aspect of psychodynamic theory, the psychosexual stage model contends that early in life we progress through a sequence of developmental stages (oral, anal, Oedipal, latency, and genital), each with its own unique mode of sexual gratification.
Psychotropic drug: A drug that changes mood or emotion, usually used when talking about drugs prescribed for various mental conditions (depression, anxiety, schizophrenia, etc.).
Punisher: A stimulus that decreases the strength of an operant behavior when it is made a consequence of the behavior.
P-value: The probability of observing a particular outcome in a sample, or more extreme, under a conjecture about the larger population or process.
Qualitative changes: Large, fundamental change, as when a caterpillar changes into a butterfly; stage theories such as Piaget’s posit that each stage reflects qualitative change relative to previous stages.
Quantitative changes: Gradual, incremental change, as in the growth of a pine tree’s girth.
Quantitative genetics: Scientific and mathematical methods for inferring genetic and environmental processes based on the degree of genetic and environmental similarity among organisms.
Quantitative law of effect: A mathematical rule that states that the effectiveness of a reinforcer at strengthening an operant response depends on the amount of reinforcement earned for all alternative behaviors. A reinforcer is less effective if there is a lot of reinforcement in the environment for other behaviors.
Quasi-experimental design: An experiment that does not require random assignment to conditions.
Random assignment: Assigning participants to receive different conditions of an experiment by chance.
Random assignment: Using a probability-based method to divide a sample into treatment groups.
Random sampling: Using a probability-based method to select a subset of individuals for the sample from the population.
Reactive person–environment transactions: The interplay between individuals and their contextual circumstances that occurs whenever attributes of the individual shape how a person perceives and responds to their environment.
Realism: A point of view that emphasizes the importance of the senses in providing knowledge of the external world.
Reappraisal, or Cognitive restructuring: The process of identifying, evaluating, and changing maladaptive thoughts in psychotherapy.
Recall memory: The process of remembering discrete episodes or events from the past, including encoding, consolidation and storage, and retrieval.
Reciprocity: The act of exchanging goods or services. By giving a person a gift, the principle of reciprocity can be used to influence others; they then feel obligated to give back.
Recoding: The ubiquitous process during learning of taking information in one form and converting it to another form, usually one more easily remembered.
Reference group effect: The tendency of people to base their self-concept on comparisons with others. For example, if your friends tend to be very smart and successful, you may come to see yourself as less intelligent and successful than you actually are. Informants also are prone to these types of effects. For instance, the sibling contrast effect refers to the tendency of parents to exaggerate the true extent of differences between their children.
Reinforcer: Any consequence of a behavior that strengthens the behavior or increases the likelihood that it will be performed it again.
Reinforcer devaluation effect: The finding that an animal will stop performing an instrumental response that once led to a reinforcer if the reinforcer is separately made aversive or undesirable.
Reliablility: The consistency of test scores across repeated assessments. For example, test-retest reliability examines the extent to which scores change over time.
Renewal effect: Recovery of an extinguished response that occurs when the context is changed after extinction. Especially strong when the change of context involves return to the context in which conditioning originally occurred. Can occur after extinction in either classical or instrumental conditioning.
Representative: In research, the degree to which a sample is a typical example of the population from which it is drawn.
Research confederate: A person working with a researcher, posing as a research participant or as a bystander.
Research design: The strategy (or “blueprint”) for deciding how to collect and analyze research information.
Research methods: The specific tools and techniques used by researchers to collect information.
Research participant: A person being studied as part of a research program.
Resting membrane potential: The voltage inside the cell relative to the voltage outside the cell while the cell is a rest (approximately -70 mV).
Retina: Cell layer in the back of the eye containing photoreceptors.
Retrieval: The process of accessing stored information.
Retroactive interference: The phenomenon whereby events that occur after some particular event of interest will usually cause forgetting of the original event.
Rods: Photoreceptors of the retina sensitive to low levels of light. Located around the fovea.
Rods: Photoreceptors that are very sensitive to light and are mostly responsible for night vision.
Rostrocaudal: A front-back plane used to identify anatomical structures in the body and the brain.
Sagittal plane: A slice that runs vertically from front to back; slices of brain in this plane divide the left and right side of the brain; this plane is similar to slicing a baked potato lengthwise.
Sample: In research, a number of people selected from a population to serve as an example of that population.
Sample: The collection of individuals on which we collect data.
Sample Size: The number of participants in a study. Sample size is important because it can influence the confidence scientists have in the accuracy and generalizability of their results.
Schema: A mental representation or set of beliefs about something.
Schema (plural: schemata): A memory template, created through repeated exposure to a particular class of objects or events.
Scientific theory: An explanation for observed phenomena that is empirically well-supported, consistent, and fruitful (predictive).
Scientist-practitioner model: A model of training of professional psychologists that emphasizes the development of both research and clinical skills.
Selection: A connection between personality attributes and aspects of the environment that occurs whenever individuals with particular attributes choose particular kinds of environments.
Selective listening: A method for studying selective attention in which people focus attention on one auditory stream of information while deliberately ignoring other auditory information.
Self-enhancement bias: The tendency for people to see and/or present themselves in an overly favorable way. This tendency can take two basic forms: defensiveness (when individuals actually believe they are better than they really are) and impression management (when people intentionally distort their responses to try to convince others that they are better than they really are). Informants also can show enhancement biases. The general form of this bias has been called the letter-of-recommendation effect, which is the tendency of informants who like the person they are rating (e.g., friends, relatives, romantic partners) to describe them in an overly favorable way. In the case of newlyweds, this tendency has been termed the honeymoon effect.
Semantic memory: The more or less permanent store of knowledge that people have.
Sensation: The physical processing of environmental stimuli by the sense organs.
Sensorimotor stage: Period within Piagetian theory from birth to age 2 years, during which children come to represent the enduring reality of objects.
Sensory adaptation: Decrease in sensitivity of a receptor to a stimulus after constant stimulation.
Sequential research designs: A research design that includes elements of cross-sectional and longitudinal research designs. Similar to cross-sectional designs, sequential research designs include participants of different ages within one study; similar to longitudinal designs, participants of different ages are followed over time.
Sexual selection: The evolution of characteristics because of the mating advantage they give organisms.
Sexual strategies theory: A comprehensive evolutionary theory of human mating that defines the menu of mating strategies humans pursue (e.g., short-term casual sex, long-term committed mating), the adaptive problems women and men face when pursuing these strategies, and the evolved solutions to these mating problems.
Shape theory of olfaction: Theory proposing that odorants of different size and shape correspond to different smells.
Sibling contrast effect: The tendency of parents to use their perceptions of all of their children as a frame of reference for rating the characteristics of each of them. For example, suppose that a mother has three children; two of these children are very sociable and outgoing, whereas the third is relatively average in sociability. Because of operation of this effect, the mother will rate this third child as less sociable and outgoing than he/she actually is. More generally, this effect causes parents to exaggerate the true extent of differences between their children. This effect represents a specific manifestation of the more general reference group effect when applied to ratings made by parents.
Signal detection: Method for studying the ability to correctly identify sensory stimuli.
Social attribution: The way a person explains the motives or behaviors of others.
Social cognition: The way people process and apply information about others.
Social influence: When one person causes a change in attitude or behavior in another person, whether intentionally or unintentionally.
Social Learning Theory: The theory that people can learn new responses and behaviors by observing the behavior of others.
Social models: Authorities that are the targets for observation and who model behaviors.
Social proof: The mental shortcut based on the assumption that, if everyone is doing it, it must be right.
Social psychology: The branch of psychological science that is mainly concerned with understanding how the presence of others affects our thoughts, feelings, and behaviors.
Social zeitgeber: Zeitgeber is German for “time giver.” Social zeitgebers are environmental cues, such as meal times and interactions with other people, that entrain biological rhythms and thus sleep-wake cycle regularity.
Sociocultural theories: Theory founded in large part by Lev Vygotsky that emphasizes how other people and the attitudes, values, and beliefs of the surrounding culture influence children’s development.
Socioeconomic status (SES): A person’s economic and social position based on income, education, and occupation.
Sodium-potassium pump: An ion channel that uses the neuron’s energy (adenosine triphosphate, ATP) to pump three Na+ ions outside the cell in exchange for bringing two K+ ions inside the cell.
Solidity principle: The idea that two solid masses should not be able to move through one another.
Soma: Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
Somatic nervous system: A part of the peripheral nervous system that uses cranial and spinal nerves in volitional actions.
Somatosensation: Ability to sense touch, pain and temperature.
Somatosensory (body sensations) cortex: The region of the parietal lobe responsible for bodily sensations; the somatosensory cortex has a contralateral representation of the human body.
Somatotopic map: Organization of the primary somatosensory cortex maintaining a representation of the arrangement of the body.
Sound waves: Changes in air pressure. The physical stimulus for audition.
Spatial resolution: A term that refers to how small the elements of an image are; high spatial resolution means the device or technique can resolve very small elements; in neuroscience it describes how small of a structure in the brain can be imaged.
Spina bifida: A developmental disease of the spinal cord, where the neural tube does not close caudally.
Spines: Protrusions on the dendrite of a neuron that form synapses with terminal buttons of the presynaptic axon.
Split-brain patient: A patient who has had most or all of his or her corpus callosum severed.
Spontaneous recovery: Recovery of an extinguished response that occurs with the passage of time after extinction. Can occur after extinction in either classical or instrumental conditioning.
Statistic: A numerical result computed from a sample (e.g., mean, proportion).
Statistical significance: A result is statistically significant if it is unlikely to arise by chance alone.
Stereotyping: A mental process of using information shortcuts about a group to effectively navigate social situations or make decisions.
Stigmatized group: A group that suffers from social disapproval based on some characteristic that sets them apart from the majority.
Stimulus control: When an operant behavior is controlled by a stimulus that precedes it.
Storage: The stage in the learning/memory process that bridges encoding and retrieval; the persistence of memory over time.
Strange situation: A laboratory task that involves briefly separating and reuniting infants and their primary caregivers as a way of studying individual differences in attachment behavior.
Stress reaction: The tendency to become easily distressed by the normal challenges of life.
Structural model: Developed to complement and extend the topographic model, the structural model of the mind posits the existence of three interacting mental structures called the id, ego, and superego.
Structuralism: A school of American psychology that sought to describe the elements of conscious experience.
Subcortical: Structures that lie beneath the cerebral cortex, but above the brain stem.
Subjective well-being: The name that scientists give to happiness—thinking and feeling that our lives are going very well.
Subjective well-being scales: Self-report surveys or questionnaires in which participants indicate their levels of subjective well-being, by responding to items with a number that indicates how well off they feel.
Suicidal ideation: Recurring thoughts about suicide, including considering or planning for suicide, or preoccupation with suicide.
Sulci: (plural) Grooves separating folds of the cortex.
Sulcus: A groove separating folds of the cortex.
Sulcus: (plural form, sulci) The crevices or fissures formed by convolutions in the brain.
Superadditive effect of multisensory integration: The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
Sympathetic nervous system: A division of the autonomic nervous system, that is faster than its counterpart that is the parasympathetic nervous system and works in opposition to it. Generally engaged in “fight or flight” functions.
Synapse: The tiny space separating neurons.
Synapse: Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Synaptic gap: Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.
Synaptic vesicles: Groups of neurotransmitters packaged together and located within the terminal button.
Synesthesia: The blending of two or more sensory experiences, or the automatic activation of a secondary (indirect) sensory experience due to certain aspects of the primary (direct) sensory stimulation.
System 1: Our intuitive decision-making system, which is typically fast, automatic, effortless, implicit, and emotional.
System 2: Our more deliberative decision-making system, which is slower, conscious, effortful, explicit, and logical.
Systematic observation: The careful observation of the natural world with the aim of better understanding it. Observations provide the basic data that allow scientists to track, tally, or otherwise organize information about the natural world.
Tastants: Chemicals transduced by taste receptor cells.
Taste aversion learning: The phenomenon in which a taste is paired with sickness, and this causes the organism to reject—and dislike—that taste in the future.
Taste receptor cells: Receptors that transduce gustatory information.
Temporal lobe: An area of the cerebrum that lies below the lateral sulcus; it contains auditory and olfactory (smell) projection regions.
Temporal lobe: The part of the cerebrum in front of (anterior to) the occipital lobe and below the lateral fissure; involved in vision, auditory processing, memory, and integrating vision and audition.
Temporal resolution: A term that refers to how small a unit of time can be measured; high temporal resolution means capable of resolving very small units of time; in neuroscience it describes how precisely in time a process can be measured in the brain.
Terminal button: The part of the end of the axon that form synapses with postsynaptic dendrite, axon, or soma.
Thalamus: A part of the diencephalon that works as a gateway for incoming and outgoing information.
The norm of reciprocity: The normative pressure to repay, in equitable value, what another person has given to us.
The rule of scarcity: People tend to perceive things as more attractive when their availability is limited, or when they stand to lose the opportunity to acquire them on favorable terms.
The triad of trust: We are most vulnerable to persuasion when the source is perceived as an authority, as honest and likable.
Theories: Groups of closely related phenomena or observations.
Threshold of excitation: Specific membrane potential that the neuron must reach to initiate an action potential.
Tip-of-the-tongue phenomenon: The inability to pull a word from memory even though there is the sensation that that word is available.
“Top-down” or internal causes of happiness: The person’s outlook and habitual response tendencies that influence their happiness—for example, their temperament or optimistic outlook on life.
Top-down processing: Experience influencing the perception of stimuli.
Topographic model: Freud’s first model of the mind, which contended that the mind could be divided into three regions: conscious, preconscious, and unconscious. (The “topographic” comes from the fact that topography is the study of maps.)
Transcranial direct current stimulation (tDCS): A neuroscience technique that passes mild electrical current directly through a brain area by placing small electrodes on the skull.
Transcranial magnetic stimulation (TMS): A neuroscience technique whereby a brief magnetic pulse is applied to the head that temporarily induces a weak electrical current that interferes with ongoing activity.
Transduction: A process in which physical energy converts into neural energy.
Transduction: The conversion of one form of energy into another.
Transformation: The term for personality changes associated with experience and life events.
Transverse plane: See “horizontal plane.”
Trichromacy theory: Theory that proposes that all of your color perception is fundamentally based on the combination of three (not two, not four) different color signals.
Trichromatic theory: Theory proposing color vision as influenced by three different cones responding preferentially to red, green and blue.
Trigger features: Specific, sometimes minute, aspects of a situation that activate fixed action patterns.
Twin studies: A behavior genetic research method that involves comparison of the similarity of identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins.
Tympanic membrane: Thin, stretched membrane in the middle ear that vibrates in response to sound. Also called the eardrum.
Type I error: In statistics, the error of rejecting the null hypothesis when it is true.
Type II error: In statistics, the error of failing to reject the null hypothesis when it is false.
Unconditional positive regard: In person-centered therapy, an attitude of warmth, empathy and acceptance adopted by the therapist in order to foster feelings of inherent worth in the patient.
Unconditioned response (UR): In classical conditioning, an innate response that is elicited by a stimulus before (or in the absence of) conditioning.
Unconditioned stimulus (US): In classical conditioning, the stimulus that elicits the response before conditioning occurs.
Validity: Evidence related to the interpretation and use of test scores. A particularly important type of evidence is criterion validity, which involves the ability of a test to predict theoretically relevant outcomes. For example, a presumed measure of conscientiousness should be related to academic achievement (such as overall grade point average).
Value: Belief about the way things should be.
Ventral pathway: Pathway of visual processing. The “what” pathway.
Verbal report paradigms: Research methods that require participants to report on their experiences, thoughts, feelings, etc., using language.
Vestibular system: Parts of the inner ear involved in balance.
Vestibulo-ocular reflex: Coordination of motion information with visual information that allows you to maintain your gaze on an object while you move.
Vicarious reinforcement: Learning that occurs by observing the reinforcement or punishment of another person.
Vignette: A short story that presents a situation that participants are asked to respond to.
Violation of expectation paradigm: A research method in which infants are expected to respond in a particular way because one of two conditions violates or goes against what they should expect based on their everyday experiences (e.g., it violates our expectations that Wile E. Coyote runs off a cliff but does not immediately fall to the ground below).
Visual hemifield: The half of visual space (what we see) on one side of fixation (where we are looking); the left hemisphere is responsible for the right visual hemifield, and the right hemisphere is responsible for the left visual hemifield.
Voluntary responses: Behaviors that a person has control over and completes by choice.
Weber’s law: States that just noticeable difference is proportional to the magnitude of the initial stimulus.
Wernicke’s area: A language area in the temporal lobe where linguistic information is comprehended (Also see Broca’s area).
What pathway: Pathway of neural processing in the brain that is responsible for your ability to recognize what is around you.
Where-and-How pathway: Pathway of neural processing in the brain that is responsible for you knowing where things are in the world and how to interact with them.
White coat hypertension: A phenomenon in which patients exhibit elevated blood pressure in the hospital or doctor’s office but not in their everyday lives.
White matter: The inner whitish regions of the cerebrum comprised of the myelinated axons of neurons in the cerebral cortex.
White matter: Regions of the nervous system that represent the axons of the nerve cells; whitish in color because of myelination of the nerve cells.
Working memory: Short transitory memory processed in the hippocampus.
Working memory: The ability to maintain information over a short period of time, such as 30 seconds or less.