Vocabulary

5α-reductase: An enzyme required to convert testosterone to 5α-dihydrotestosterone.
Absolute stability: Consistency in the level or amount of a personality attribute over time.
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.
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.
Aggression: A form of social interaction that includes threat, attack, and fighting.
Agnosias: Due to damage of Wernicke’s area. An inability to recognize objects, words, or faces.
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.
Agreeableness: A core personality trait that includes such dispositional characteristics as being sympathetic, generous, forgiving, and helpful, and behavioral tendencies toward harmonious social relations and likeability.
Alogia: A reduction in the amount of speech and/or increased pausing before the initiation of speech.
Altruism: A motivation for helping that has the improvement of another’s welfare as its ultimate goal, with no expectation of any benefits for the helper.
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.
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.
Animism: The belief that everyone and everything had a “soul” and that mental illness was due to animistic causes, for example, evil spirits controlling an individual and his/her behavior.
Anterograde amnesia: Inability to form new memories for facts and events after the onset of amnesia.
Antisocial: A pervasive pattern of disregard and violation of the rights of others. These behaviors may be aggressive or destructive and may involve breaking laws or rules, deceit or theft.
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.
Aromatase: An enzyme that converts androgens into estrogens.
Arousal: cost–reward model: An egoistic theory proposed by Piliavin et al. (1981) that claims that seeing a person in need leads to the arousal of unpleasant feelings, and observers are motivated to eliminate that aversive state, often by helping the victim. A cost–reward analysis may lead observers to react in ways other than offering direct assistance, including indirect help, reinterpretation of the situation, or fleeing the scene.
Asylum: A place of refuge or safety established to confine and care for the mentally ill; forerunners of the mental hospital or psychiatric facility.
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.
Attraction: A connection between personality attributes and aspects of the environment that occurs because individuals with particular traits are drawn to certain environments.
Attributional style: The tendency by which a person infers the cause or meaning of behaviors or events.
Attrition: A connection between personality attributes and aspects of the environment that occurs because individuals with particular traits drop out from certain environments.
Autobiographical memory: Memory for the events of one’s life.
Automatic: Automatic biases are unintended, immediate, and irresistible.
Automatic empathy: A social perceiver unwittingly taking on the internal state of another person, usually because of mimicking the person’s expressive behavior and thereby feeling the expressed emotion.
Autonomic nervous system: A part of the peripheral nervous system that connects to glands and smooth muscles. Consists of sympathetic and parasympathetic divisions.
Aversive racism: Aversive racism is unexamined racial bias that the person does not intend and would reject, but that avoids inter-racial contact.
Avoidant: A pervasive pattern of social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation.
Axon: Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Basic-level category: The neutral, preferred category for a given object, at an intermediate level of specificity.
Behavioral genetics: The empirical science of how genes and environments combine to generate behavior.
Biases: The systematic and predictable mistakes that influence the judgment of even very talented human beings.
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.
Biopsychosocial model: A model in which the interaction of biological, psychological, and sociocultural factors is seen as influencing the development of the individual.
Birth cohort: Individuals born in a particular year or span of time.
Blatant biases: Blatant biases are conscious beliefs, feelings, and behavior that people are perfectly willing to admit, are mostly hostile, and openly favor their own group.
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.
Borderline: A pervasive pattern of instability of interpersonal relationships, self-image, and affects, and marked impulsivity.
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.
Broca’s area: An area in the frontal lobe of the left hemisphere. Implicated in language production.
Bystander intervention: The phenomenon whereby people intervene to help others in need even if the other is a complete stranger and the intervention puts the helper at risk.
Cartesian catastrophe: The idea that mental processes taking place outside conscious awareness are impossible.
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.
Category: A set of entities that are equivalent in some way. Usually the items are similar to one another.
Cathartic method: A therapeutic procedure introduced by Breuer and developed further by Freud in the late 19th century whereby a patient gains insight and emotional relief from recalling and reliving traumatic events.
Cell membrane: A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.
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.
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.
Chromosomal sex: The sex of an individual as determined by the sex chromosomes (typically XX or XY) received at the time of fertilization.
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: Snail-shell-shaped organ that transduces mechanical vibrations into neural signals.
Cohort effects: Differences in personality that are related to historical and social factors unique to individuals born in a particular year.
Computerized axial tomography: A noninvasive brain-scanning procedure that uses X-ray absorption around the head.
Concept: The mental representation of a category.
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.
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.
Conscious: Having knowledge of something external or internal to oneself; being aware of and responding to one’s surroundings.
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: Process by which a memory trace is stabilized and transformed into a more durable form.
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.
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.
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.
Cost–benefit analysis: A decision-making process that compares the cost of an action or thing against the expected benefit to help determine the best course of action.
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.
Cultural relativism: The idea that cultural norms and values of a society can only be understood on their own terms or in their own context.
Cumulative continuity principle: The generalization that personality attributes show increasing stability with age and experience.
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.
Decay: The fading of memories with the passage of time.
Declarative memory: Conscious memories for facts and events.
Defeminization: The removal of the potential for female traits.
Delusions: False beliefs that are often fixed, hard to change even in the presence of conflicting information, and often culturally influenced in their content.
Demasculinization: The removal of the potential for male traits.
Dendrite: Part of a neuron that extends away from the cell body and is the main input to the neuron.
Dependent: A pervasive and excessive need to be taken care of that leads to submissive and clinging behavior and fears of separation.
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).
Dichotic listening: An experimental task in which two messages are presented to different ears.
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.
Diffusion: The force on molecules to move from areas of high concentration to areas of low concentration.
Diffusion of responsibility: When deciding whether to help a person in need, knowing that there are others who could also provide assistance relieves bystanders of some measure of personal responsibility, reducing the likelihood that bystanders will intervene.
Dihydrotestosterone (DHT): A primary androgen that is an androgenic steroid product of testosterone and binds strongly to androgen receptors.
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.
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.
Dissociative amnesia: Loss of autobiographical memories from a period in the past in the absence of brain injury or disease.
Distinctiveness: The principle that unusual events (in a context of similar events) will be recalled and recognized better than uniform (nondistinctive) events.
Distractor task: A task that is designed to make a person think about something unrelated to an impending decision.
Divided attention: The ability to flexibly allocate attentional resources between two or more concurrent tasks.
DNA methylation: Covalent modifications of mammalian DNA occurring via the methylation of cytosine, typically in the context of the CpG dinucleotide.
DNA methyltransferases (DNMTs): Enzymes that establish and maintain DNA methylation using methyl-group donor compounds or cofactors. The main mammalian DNMTs are DNMT1, which maintains methylation state across DNA replication, and DNMT3a and DNMT3b, which perform de novo methylation.
Dopamine: A neurotransmitter in the brain that is thought to play an important role in regulating the function of other neurotransmitters.
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.
Ectoderm: The outermost layer of a developing fetus.
EEG: (Electroencephalography) The recording of the brain’s electrical activity over a period of time by placing electrodes on the scalp.
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).
Egoism: A motivation for helping that has the improvement of the helper’s own circumstances as its primary goal.
Electroencephalography: A technique that is used to measure gross electrical activity of the brain by placing electrodes on the scalp.
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.
Empathic concern: According to Batson’s empathy–altruism hypothesis, observers who empathize with a person in need (that is, put themselves in the shoes of the victim and imagine how that person feels) will experience empathic concern and have an altruistic motivation for helping.
Empathy–altruism model: An altruistic theory proposed by Batson (2011) that claims that people who put themselves in the shoes of a victim and imagining how the victim feel will experience empathic concern that evokes an altruistic motivation for helping.
Empirical methods: Approaches to inquiry that are tied to actual measurement and observation.
Encoding: Process by which information gets into memory.
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.
Endocrine gland: A ductless gland from which hormones are released into the blood system in response to specific biological signals.
Engrams: A term indicating the change in the nervous system representing an event; also, memory trace.
Epigenetics: The study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. Epigenetic marks include covalent DNA modifications and posttranslational histone modifications.
Epigenome: The genome-wide distribution of epigenetic marks.
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.
Estrogen: Any of the C18 class of steroid hormones, so named because of the estrus-generating properties in females. Biologically important estrogens include estradiol and estriol.
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.
Etiology: The causal description of all of the factors that contribute to the development of a disorder or illness.
Eureka experience: When a creative product enters consciousness.
Event-related potentials: A physiological measure of large electrical change in the brain produced by sensory stimulation or motor responses.
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?
Excitatory postsynaptic potentials: A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.
Exemplar: An example in memory that is labeled as being in a particular category.
Experimenter expectations: When the experimenter’s expectations influence the outcome of a study.
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.
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.
False-belief test: An experimental procedure that assesses whether a perceiver recognizes that another person has a false belief—a belief that contradicts reality.
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.
Feminization: The induction of female traits.
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.
Five-Factor Model: Five broad domains or dimensions that are used to describe human personality.
Flashbulb memory: Vivid personal memories of receiving the news of some momentous (and usually emotional) event.
Flat affect: A reduction in the display of emotions through facial expressions, gestures, and speech intonation.
Foils: Any member of a lineup (whether live or photograph) other than the suspect.
Folk explanations of behavior: People’s natural explanations for why somebody did something, felt something, etc. (differing substantially for unintentional and intentional behaviors).
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.
Frontal lobe: The most forward region (close to forehead) of the cerebral hemispheres.
Functional capacity: The ability to engage in self-care (cook, clean, bathe), work, attend school, and/or engage in social relationships.
Functional distance: The frequency with which we cross paths with others.
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).
Gene: A specific deoxyribonucleic acid (DNA) sequence that codes for a specific polypeptide or protein or an observable inherited trait.
Gene Selection Theory: The modern theory of evolution by selection by which differential gene replication is the defining process of evolutionary change.
Genome-wide association study (GWAS): A study that maps DNA polymorphisms in affected individuals and controls matched for age, sex, and ethnic background with the aim of identifying causal genetic variants.
Genotype: The DNA content of a cell’s nucleus, whether a trait is externally observable or not.
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.
Gonadal sex: The sex of an individual as determined by the possession of either ovaries or testes. Females have ovaries, whereas males have testes.
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: 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.
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.
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).
Helpfulness: A component of the prosocial personality orientation; describes individuals who have been helpful in the past and, because they believe they can be effective with the help they give, are more likely to be helpful in the future.
Helping: Prosocial acts that typically involve situations in which one person is in need and another provides the necessary assistance to eliminate the other’s need.
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: 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.
Histone acetyltransferases (HATs) and histone deacetylases (HDACs): HATs are enzymes that transfer acetyl groups to specific positions on histone tails, promoting an “open” chromatin state and transcriptional activation. HDACs remove these acetyl groups, resulting in a “closed” chromatin state and transcriptional repression.
Histone modifications: Posttranslational modifications of the N-terminal “tails” of histone proteins that serve as a major mode of epigenetic regulation. These modifications include acetylation, phosphorylation, methylation, sumoylation, ubiquitination, and ADP-ribosylation.
Histrionic: A pervasive pattern of excessive emotionality and attention seeking.
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.
Hormone: An organic chemical messenger released from endocrine cells that travels through the blood to interact with target cells at some distance to cause a biological response.
Hostile attribution bias: The tendency of some individuals to interpret ambiguous social cues and interactions as examples of aggressiveness, disrespect, or antagonism.
Humorism (or humoralism): A belief held by ancient Greek and Roman physicians (and until the 19th century) that an excess or deficiency in any of the four bodily fluids, or humors—blood, black bile, yellow bile, and phlegm—directly affected their health and temperament.
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.
Hysteria: Term used by the ancient Greeks and Egyptians to describe a disorder believed to be caused by a woman’s uterus wandering throughout the body and interfering with other organs (today referred to as conversion disorder, in which psychological problems are expressed in physical form).
Identical twins: Two individual organisms that originated from the same zygote and therefore are genetically identical or very similar. The epigenetic profiling of identical twins discordant for disease is a unique experimental design as it eliminates the DNA sequence-, age-, and sex-differences from consideration.
Immunocytochemistry: A method of staining tissue including the brain, using antibodies.
Implicit Association Test: Implicit Association Test (IAT) measures relatively automatic biases that favor own group relative to other groups.
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 object when attention is devoted to something else.
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 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.
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.
Inhibitory postsynaptic potentials: A hyperpolarizing postsynaptic current that causes the membrane potential to become more negative and move away from the threshold of excitation.
Instrumental conditioning: Process in which animals learn about the relationship between their behaviors and their consequences. Also known as operant conditioning.
Intention: An agent’s mental state of committing to perform an action that the agent believes will bring about a desired outcome.
Intentionality: The quality of an agent’s performing a behavior intentionally—that is, with skill and awareness and executing an intention (which is in turn based on a desire and relevant beliefs).
Interaural differences: Differences (usually in time or intensity) between the two ears.
Interference: Other memories get in the way of retrieving a desired memory
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.
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.
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.
Joint attention: Two people attending to the same object and being aware that they both are attending to it.
Kin selection: According to evolutionary psychology, the favoritism shown for helping our blood relatives, with the goals of increasing the likelihood that some portion of our DNA will be passed on to future generations.
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.
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 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.
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.
Limbic system: A loosely defined network of nuclei in the brain involved with learning and emotion.
Limited capacity: The notion that humans have limited mental resources that can be used at a given 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).
Maladaptive: Term referring to behaviors that cause people who have them physical or emotional harm, prevent them from functioning in daily life, and/or indicate that they have lost touch with reality and/or cannot control their thoughts and behavior (also called dysfunctional).
Manipulation: A connection between personality attributes and aspects of the environment that occurs whenever individuals with particular traits actively shape their environments.
Masculinization: The induction of male traits.
Maternal behavior: Parental behavior performed by the mother or other female.
Maturity principle: The generalization that personality attributes associated with the successful fulfillment of adult roles increase with age and experience.
Medial temporal lobes: Inner region of the temporal lobes that includes the hippocampus.
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.
Mere-exposure effect: The notion that people like people/places/things merely because they are familiar with them.
Mere-exposure effects: The result of developing a more positive attitude towards a stimulus after repeated instances of mere exposure to it.
Mesmerism: Derived from Franz Anton Mesmer in the late 18th century, an early version of hypnotism in which Mesmer claimed that hysterical symptoms could be treated through animal magnetism emanating from Mesmer’s body and permeating the universe (and later through magnets); later explained in terms of high suggestibility in individuals.
Mimicry: Copying others’ behavior, usually without awareness.
Mirror neurons: Neurons identified in monkey brains that fire both when the monkey performs a certain action and when it perceives another agent performing that action.
Misinformation effect: When erroneous information occurring after an event is remembered as having been part of the original event.
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).
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.
Model minority: A minority group whose members are perceived as achieving a higher degree of socioeconomic success than the population average.
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.
Narcissistic: A pervasive pattern of grandiosity (in fantasy or behavior), need for admiration, and lack of empathy.
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.
Negative state relief model: An egoistic theory proposed by Cialdini et al. (1982) that claims that people have learned through socialization that helping can serve as a secondary reinforcement that will relieve negative moods such as sadness.
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 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 messenger that travels between neurons to provide communication. Some neurotransmitters, such as norepinephrine, can leak into the blood system and act as hormones.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
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.
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.
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.
Observational learning: Learning by observing the behavior of others.
Obsessive-compulsive: A pervasive pattern of preoccupation with orderliness, perfectionism, and mental and interpersonal control, at the expense of flexibility, openness, and efficiency.
Occipital lobe: The back part of the cerebrum, which houses the visual areas.
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.
Other-oriented empathy: A component of the prosocial personality orientation; describes individuals who have a strong sense of social responsibility, empathize with and feel emotionally tied to those in need, understand the problems the victim is experiencing, and have a heightened sense of moral obligations to be helpful.
Overconfident: The bias to have greater confidence in your judgment than is warranted based on a rational assessment.
Oxytocin: A peptide hormone secreted by the pituitary gland to trigger lactation, as well as social bonding.
Paranoid: A pervasive distrust and suspiciousness of others such that their motives are interpreted as malevolent.
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.
Parental behavior: Behaviors performed in relation to one’s offspring that contributes directly to the survival of those offspring
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.
Paternal behavior: Parental behavior performed by the father or other male.
Pavlovian conditioning: See classical conditioning.
Perceived social support: A person’s perception that others are there to help them in times of need.
Personal distress: According to Batson’s empathy–altruism hypothesis, observers who take a detached view of a person in need will experience feelings of being “worried” and “upset” and will have an egoistic motivation for helping to relieve that distress.
Personality: Characteristic, routine ways of thinking, feeling, and relating to others.
Personality: Enduring predispositions that characterize a person, such as styles of thought, feelings and behavior.
Personality disorders: When personality traits result in significant distress, social impairment, and/or occupational impairment.
Personality traits: Enduring dispositions in behavior that show differences across individuals, and which tend to characterize the person across varying types of situations.
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.
Phenotype: The pattern of expression of the genotype or the magnitude or extent to which it is observably expressed—an observable characteristic or trait of an organism, such as its morphology, development, biochemical or physiological properties, or behavior.
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.
Piaget’s theory: Theory that development occurs through a sequence of discontinuous stages: the sensorimotor, preoperational, concrete operational, and formal operational stages.
Pinna: Visible part of the outer ear.
Placebo effect: When receiving special treatment or something new affects human behavior.
Pluralistic ignorance: Relying on the actions of others to define an ambiguous need situation and to then erroneously conclude that no help or intervention is necessary.
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.
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: (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.
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: Prejudice is an evaluation or emotion toward people merely based 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 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 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.
Processing speed: The speed with which an individual can perceive auditory or visual information and respond to it.
Progesterone: A primary progestin that is involved in pregnancy and mating behaviors.
Progestin: A class of C21 steroid hormones named for their progestational (pregnancy-supporting) effects. Progesterone is a common progestin.
Prohormone: A molecule that can act as a hormone itself or be converted into another hormone with different properties. For example, testosterone can serve as a hormone or as a prohormone for either dihydrotestosterone or estradiol.
Projection: A social perceiver’s assumption that the other person wants, knows, or feels the same as the perceiver wants, know, or feels.
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.
Prolactin: A protein hormone that is highly conserved throughout the animal kingdom. It has many biological functions associated with reproduction and synergistic actions with steroid hormones.
Prosocial behavior: Social behavior that benefits another person.
Prosocial personality orientation: A measure of individual differences that identifies two sets of personality characteristics (other-oriented empathy, helpfulness) that are highly correlated with prosocial behavior.
Proximity: Physical nearness.
Psychic causality: The assumption that nothing in mental life happens by chance—that there is no such thing as a “random” thought or feeling.
Psychogenesis: Developing from psychological origins.
Psychological adaptations: Mechanisms of the mind that evolved to solve specific problems of survival or reproduction; conceptualized as information processing devices.
Psychological essentialism: The belief that members of a category have an unseen property that causes them to be in the category and to have the properties associated with it.
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.
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.
Punisher: A stimulus that decreases the strength of an operant behavior when it is made a consequence of the behavior.
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.
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.
Received social support: The actual act of receiving support (e.g., informational, functional).
Receptor: A chemical structure on the cell surface or inside of a cell that has an affinity for a specific chemical configuration of a hormone, neurotransmitter, or other compound.
Reciprocal altruism: According to evolutionary psychology, a genetic predisposition for people to help those who have previously helped them.
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.
Resting membrane potential: The voltage inside the cell relative to the voltage outside the cell while the cell is a rest (approximately -70 mV).
Retrieval: Process by which information is accessed from memory and utilized.
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.
Retrograde amnesia: Inability to retrieve memories for facts and events acquired before the onset of amnesia.
Right-wing authoritarianism: Right-wing authoritarianism (RWA) focuses on value conflicts but endorses respect for obedience and authority in the service of group conformity.
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.
Schema (plural: schemata): A memory template, created through repeated exposure to a particular class of objects or events.
Schizoid: A pervasive pattern of detachment from social relationships and a restricted range of expression of emotions in interpersonal settings.
Schizotypal: A pervasive pattern of social and interpersonal deficits marked by acute discomfort with, and reduced capacity for, close relationships as well as perceptual distortions and eccentricities of behavior.
Selection: A connection between personality attributes and aspects of the environment that occurs whenever individuals with particular attributes choose particular kinds of environments.
Selective attention: The ability to select certain stimuli in the environment to process, while ignoring distracting information.
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-categorization theory: Self-categorization theory develops social identity theory’s point that people categorize themselves, along with each other into groups, favoring their own group.
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.
Sensorimotor stage: Period within Piagetian theory from birth to age 2 years, during which children come to represent the enduring reality of objects.
Sex determination: The point at which an individual begins to develop as either a male or a female. In animals that have sex chromosomes, this occurs at fertilization. Females are XX and males are XY. All eggs bear X chromosomes, whereas sperm can either bear X or Y chromosomes. Thus, it is the males that determine the sex of the offspring.
Sex differentiation: The process by which individuals develop the characteristics associated with being male or female. Differential exposure to gonadal steroids during early development causes sexual differentiation of several structures including the brain.
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.
Shadowing: A task in which the individual is asked to repeat an auditory message as it is presented.
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.
Simulation: The process of representing the other person’s mental state.
Social dominance orientation: Social dominance orientation (SDO) describes a belief that group hierarchies are inevitable in all societies and even good, to maintain order and stability.
Social identity theory: Social identity theory notes that people categorize each other into groups, favoring their own group.
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 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.
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.
Somatogenesis: Developing from physical/bodily origins.
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.
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.
Stereotype Content Model: Stereotype Content Model shows that social groups are viewed according to their perceived warmth and competence.
Stereotypes: Stereotype is a belief that characterizes people based merely on their group membership.
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.
Subliminal perception: The ability to process information for meaning when the individual is not consciously aware of that information.
Subtle biases: Subtle biases are automatic, ambiguous, and ambivalent, but real in their consequences.
Suicidal ideation: Recurring thoughts about suicide, including considering or planning for suicide, or preoccupation with suicide.
Sulcus: (plural form, sulci) The crevices or fissures formed by convolutions in the brain.
Supernatural: Developing from origins beyond the visible observable universe.
Support support network: The people who care about and support a person.
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: 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.
Synchrony: Two people displaying the same behaviors or having the same internal states (typically because of mutual mimicry).
Syndrome: Involving a particular group of signs and symptoms.
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.
Target cell: A cell that has receptors for a specific chemical messenger (hormone or neurotransmitter).
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.
Temporal lobe: An area of the cerebrum that lies below the lateral sulcus; it contains auditory and olfactory (smell) projection regions.
Temporally graded retrograde amnesia: Inability to retrieve memories from just prior to the onset of amnesia with intact memory for more remote events.
Terminal button: The part of the end of the axon that form synapses with postsynaptic dendrite, axon, or soma.
Testosterone: The primary androgen secreted by the testes of most vertebrate animals, including men.
Thalamus: A part of the diencephalon that works as a gateway for incoming and outgoing information.
Theories: Groups of closely related phenomena or observations.
Theory of mind: The human capacity to understand minds, a capacity that is made up of a collection of concepts (e.g., agent, intentionality) and processes (e.g., goal detection, imitation, empathy, perspective taking).
Threshold of excitation: Specific membrane potential that the neuron must reach to initiate an action potential.
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.)
“Traitement moral” (moral treatment): A therapeutic regimen of improved nutrition, living conditions, and rewards for productive behavior that has been attributed to Philippe Pinel during the French Revolution, when he released mentally ill patients from their restraints and treated them with compassion and dignity rather than with contempt and denigration.
Transduction: A process in which physical energy converts into neural energy.
Transformation: The term for personality changes associated with experience and life events.
Trephination: The drilling of a hole in the skull, presumably as a way of treating psychological disorders.
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.
Twin studies: A behavior genetic research method that involves comparison of the similarity of identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins.
Tympanic membrane: Ear drum, which separates the outer ear from the middle ear.
Typicality: The difference in “goodness” of category members, ranging from the most typical (the prototype) to borderline members.
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.
Unconscious: Not conscious; the part of the mind that affects behavior though it is inaccessible to the conscious mind.
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).
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.
Visual perspective taking: Can refer to visual perspective taking (perceiving something from another person’s spatial vantage point) or more generally to effortful mental state inference (trying to infer the other person’s thoughts, desires, emotions).
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 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.