Vocabulary

Action Potential: A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Action potential: A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Affect: Feelings that can be described in terms of two dimensions, the dimensions of arousal and valence (Figure 2). For example, high arousal positive states refer to excitement, elation, and enthusiasm. Low arousal positive states refer to calm, peacefulness, and relaxation. Whereas “actual affect” refers to the states that people actually feel, “ideal affect” refers to the states that people ideally want to feel.
Affective forecasting: Predicting how one will feel in the future after some event or decision.
Agoraphobia: A sort of anxiety disorder distinguished by feelings that a place is uncomfortable or may be unsafe because it is significantly open or crowded.
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.
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.
Anxiety: A mood state characterized by negative affect, muscle tension, and physical arousal in which a person apprehensively anticipates future danger or misfortune.
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.
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 psychological tendency that is expressed by evaluating a particular entity with some degree of favor or disfavor.
Attributional style: The tendency by which a person infers the cause or meaning of behaviors or events.
Autobiographical memory: Memory for the events of one’s life.
Automatic: A behavior or process has one or more of the following features: unintentional, uncontrollable, occurring outside of conscious awareness, and cognitively efficient.
Automatic: Automatic biases are unintended, immediate, and irresistible.
Availability heuristic: A heuristic in which the frequency or likelihood of an event is evaluated based on how easily instances of it come to mind.
Aversive racism: Aversive racism is unexamined racial bias that the person does not intend and would reject, but that avoids inter-racial contact.
Axon: Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Axon: Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
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).
Biological vulnerability: A specific genetic and neurobiological factor that might predispose someone to develop anxiety disorders.
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.
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.
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.
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.
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 Nervous System: The portion of the nervous system that includes the brain and spinal cord.
Cerebellum: The distinctive structure at the back of the brain, Latin for “small brain.”
Cerebrum: Usually refers to the cerebral cortex and associated white matter, but in some texts includes the subcortical structures.
Chameleon effect: The tendency for individuals to nonconsciously mimic the postures, mannerisms, facial expressions, and other behaviors of one’s interaction partners.
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).
Chunk: The process of grouping information together using our knowledge.
Chutes and Ladders: A numerical board game that seems to be useful for building numerical knowledge.
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.
Classical conditioning: Describes stimulus-stimulus associative learning.
Collectivism: Belief system that emphasizes the duties and obligations that each person has toward others.
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: A learned reaction following classical conditioning, or the process by which an event that automatically elicits a response is repeatedly paired with another neutral stimulus (conditioned stimulus), resulting in the ability of the neutral stimulus to elicit the same response on its own.
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.
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.
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.
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).
Corpus Callosum: The thick bundle of nerve cells that connect the two hemispheres of the brain and allow them to communicate.
Correlation: Measures the association between two variables, or how they go together.
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.
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 display rules: These are rules that are learned early in life that specify the management and modification of emotional expressions according to social circumstances. Cultural display rules can work in a number of different ways. For example, they can require individuals to express emotions “as is” (i.e., as they feel them), to exaggerate their expressions to show more than what is actually felt, to tone down their expressions to show less than what is actually felt, to conceal their feelings by expressing something else, or to show nothing at all.
Culture: Shared, socially transmitted ideas (e.g., values, beliefs, attitudes) that are reflected in and reinforced by institutions, products, and rituals.
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.
Dendrites: 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).
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.
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.
Directional goals: The motivation to reach a particular outcome or judgment.
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.
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.
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.
Durability bias: A bias in affective forecasting in which one overestimates for how long one will feel an emotion (positive or negative) after some event.
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.
Egoism: A motivation for helping that has the improvement of the helper’s own circumstances as its primary goal.
Electroencephalography (EEG): A neuroimaging technique that measures electrical brain activity via multiple 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.
Emerging adulthood: A new life stage extending from approximately ages 18 to 25, during which the foundation of an adult life is gradually constructed in love and work. Primary features include identity explorations, instability, focus on self-development, feeling incompletely adult, and a broad sense of possibilities.
Emotions: Changes in subjective experience, physiological responding, and behavior in response to a meaningful event. Emotions tend to occur on the order of seconds (in contract to moods which may last for days).
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.
Encoding: The pact of putting information 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.
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: The ability to learn and retrieve new information or episodes in one’s life.
Episodic memory: Memory for events in a particular time and place.
Evaluative priming task: An implicit attitude task that assesses the extent to which an attitude object is associated with a positive or negative valence by measuring the time it takes a person to label an adjective as good or bad after being presented with an attitude object.
Excitatory postsynaptic potentials: A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.
Experimenter expectations: When the experimenter’s expectations influence the outcome of a study.
Explicit attitude: An attitude that is consciously held and can be reported on by the person holding the attitude.
External cues: Stimuli in the outside world that serve as triggers for anxiety or as reminders of past traumatic events.
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.
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.
Feelings: A general term used to describe a wide range of states that include emotions, moods, traits and that typically involve changes in subjective experience, physiological responding, and behavior in response to a meaningful event. Emotions typically occur on the order of seconds, whereas moods may last for days, and traits are tendencies to respond a certain way across various situations.
Fight or flight response: A biological reaction to alarming stressors that prepares the body to resist or escape a threat.
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.
Flashback: Sudden, intense re-experiencing of a previous event, usually trauma-related.
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.
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.
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.
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 (fMRI): Functional magnetic resonance imaging (fMRI): A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood.
G: Short for “general factor” and is often used to be synonymous with intelligence itself.
g or general mental ability: The general factor common to all cognitive ability measures, “a very general mental capacity that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings—‘catching on,’ ‘making sense of things,’ or ‘figuring out’ what to do” (Gottfredson, 1997, p. 13).
Gene: A specific deoxyribonucleic acid (DNA) sequence that codes for a specific polypeptide or protein or an observable inherited trait.
Generalizability: Related to whether the results from the sample can be generalized to a larger population.
Generalized anxiety disorder (GAD): Excessive worry about everyday things that is at a level that is out of proportion to the specific causes of worry.
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.
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.
Grandiosity: Inflated self-esteem or an exaggerated sense of self-importance and self-worth (e.g., believing one has special powers or superior abilities).
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: Occurs when the response to a stimulus decreases with exposure.
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.
Heuristics: A mental shortcut or rule of thumb that reduces complex mental problems to more simple rule-based decisions.
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.
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.
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.
Hot cognition: The mental processes that are influenced by desires and feelings.
Hypersomnia: Excessive daytime sleepiness, including difficulty staying awake or napping, or prolonged sleep episodes.
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.
Impact bias: A bias in affective forecasting in which one overestimates the strength or intensity of emotion one will experience after some event.
Implicit Association Test: An implicit attitude task that assesses a person’s automatic associations between concepts by measuring the response times in pairing the concepts.
Implicit Association Test: Implicit Association Test (IAT) measures relatively automatic biases that favor own group relative to other groups.
Implicit attitude: An attitude that a person cannot verbally or overtly state.
Implicit learning: Occurs when we acquire information without intent that we cannot easily express.
Implicit measures of attitudes: Measures of attitudes in which researchers infer the participant’s attitude rather than having the participant explicitly report it.
Implicit memory: A type of long-term memory that does not require conscious thought to encode. It's the type of memory one makes without intent.
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).
Incidental learning: Any type of learning that happens without the intention to learn.
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 self: A model or view of the self as distinct from others and as stable across different situations. The goal of the independent self is to express and assert the self, and to influence others. This model of self is prevalent in many individualistic, Western contexts (e.g., the United States, Australia, Western Europe).
Independent variable: The variable the researcher manipulates and controls in an experiment.
Individualism: Belief system that exalts freedom, independence, and individual choice as high values.
Industrialized countries: The economically advanced countries of the world, in which most of the world’s wealth is concentrated.
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.
Intelligence: An individual’s cognitive capability. This includes the ability to acquire, process, recall and apply information.
Intentional learning: Any type of learning that happens when motivated by intention.
Interdependent self: A model or view of the self as connected to others and as changing in response to different situations. The goal of the interdependent self is to suppress personal preferences and desires, and to adjust to others. This model of self is prevalent in many collectivistic, East Asian contexts (e.g., China, Japan, Korea).
Internal bodily or somatic cues: Physical sensations that serve as triggers for anxiety or as reminders of past traumatic events.
Interoceptive avoidance: Avoidance of situations or activities that produce sensations of physical arousal similar to those occurring during a panic attack or intense fear response.
Interpersonal: This refers to the relationship or interaction between two or more individuals in a group. Thus, the interpersonal functions of emotion refer to the effects of one’s emotion on others, or to the relationship between oneself and others.
Intrapersonal: This refers to what occurs within oneself. Thus, the intrapersonal functions of emotion refer to the effects of emotion to individuals that occur physically inside their bodies and psychologically inside their minds.
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.
IQ: Short for “intelligence quotient.” This is a score, typically obtained from a widely used measure of intelligence that is meant to rank a person’s intellectual ability against that of others.
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.
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.
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: Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Longitudinal study: A study that follows the same group of individuals over time.
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.
Margin of error: The expected amount of random variation in a statistic; often defined for 95% confidence level.
Memory traces: A term indicating the change in the nervous system representing an event.
Metacognition: Describes the knowledge and skills people have in monitoring and controlling their own learning and memory.
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.
Model minority: A minority group whose members are perceived as achieving a higher degree of socioeconomic success than the population average.
Mood-congruent memory: The tendency to be better able to recall memories that have a mood similar to our current mood.
Motivated skepticism: A form of bias that can result from having a directional goal in which one is skeptical of evidence despite its strength because it goes against what one wants to believe.
Myelin Sheath: Fatty tissue, 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.
Nature: The genes that children bring with them to life and that influence all aspects of their development.
Need for closure: The desire to come to a decision that will resolve ambiguity and conclude an issue.
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.
Nervous System: The body’s network for electrochemical communication. This system includes all the nerves cells in the body.
Neurodevelopmental: Processes that influence how the brain develops either in utero or as the child is growing up.
Neurons: Individual brain cells
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.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Nonassociative learning: Occurs when a single repeated exposure leads to a change in behavior.
Non-industrialized countries: The less economically advanced countries that comprise the majority of the world’s population. Most are currently developing at a rapid rate.
Norm: Assessments are given to a representative sample of a population to determine the range of scores for that population. These “norms” are then used to place an individual who takes that assessment on a range of scores in which he or she is compared to the population at large.
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.
Observational learning: Learning by observing the behavior of others.
Obsessive-compulsive disorder (OCD): A disorder characterized by the desire to engage in certain behaviors excessively or compulsively in hopes of reducing anxiety. Behaviors include things such as cleaning, repeatedly opening and closing doors, hoarding, and obsessing over certain thoughts.
Occipital Lobe: The back most (posterior) part of the cerebrum; involved in vision.
OECD countries: Members of the Organization for Economic Co-operation and Development, comprised of the world’s wealthiest countries.
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: Describes stimulus-response associative learning.
Operant conditioning: See instrumental conditioning.
Operational definitions: How researchers specifically measure a concept.
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.
Panic disorder (PD): A condition marked by regular strong panic attacks, and which may include significant levels of worry about future attacks.
Parameter: A numerical result summarizing a population (e.g., mean, proportion).
Parietal Lobe: The part of the cerebrum between the frontal and occipital lobes; involved in bodily sensations, visual attention, and integrating the senses.
Participant demand: When participants behave in a way that they think the experimenter wants them to behave.
Pavlovian conditioning: See classical conditioning.
Perceptual learning: Occurs when aspects of our perception changes as a function of experience.
Peripheral Nervous System: All of the nerve cells that connect the central nervous system to all the other parts of the body.
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: 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-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.
Piaget’s theory: Theory that development occurs through a sequence of discontinuous stages: the sensorimotor, preoperational, concrete operational, and formal operational stages.
Placebo effect: When receiving special treatment or something new affects human behavior.
Planning fallacy: A cognitive bias in which one underestimates how long it will take to complete a task.
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.
Population: A larger collection of individuals that we would like to generalize our results to.
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.
Posttraumatic stress disorder (PTSD): A sense of intense fear, triggered by memories of a past traumatic event, that another traumatic event might occur. PTSD may include feelings of isolation and emotional numbing.
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.
Primed: A process by which a concept or behavior is made more cognitively accessible or likely to occur through the presentation of an associated concept.
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.
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.
Psychological vulnerabilities: Influences that our early experiences have on how we view the world.
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.
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 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.
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.
Reinforced response: Following the process of operant conditioning, the strengthening of a response following either the delivery of a desired consequence (positive reinforcement) or escape from an aversive consequence.
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.
Representativeness heuristic: A heuristic in which the likelihood of an object belonging to a category is evaluated based on the extent to which the object appears similar to one’s mental representation of the category.
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: 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.
Right-wing authoritarianism: Right-wing authoritarianism (RWA) focuses on value conflicts but endorses respect for obedience and authority in the service of group conformity.
SAD performance only: Social anxiety disorder which is limited to certain situations that the sufferer perceives as requiring some type of performance.
Sample: The collection of individuals on which we collect data.
Satisfaction: Correspondence between an individual’s needs or preferences and the rewards offered by the environment.
Satisfactoriness: Correspondence between an individual’s abilities and the ability requirements of the environment.
Schema: A mental model or representation that organizes the important information about a thing, person, or event (also known as a script).
Schema (plural: schemata): A memory template, created through repeated exposure to a particular class of objects or events.
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.
Sensitization: Occurs when the response to a stimulus increases with exposure
Sensorimotor stage: Period within Piagetian theory from birth to age 2 years, during which children come to represent the enduring reality of objects.
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.
Social and cultural: Society refers to a system of relationships between individuals and groups of individuals; culture refers to the meaning and information afforded to that system that is transmitted across generations. Thus, the social and cultural functions of emotion refer to the effects that emotions have on the functioning and maintenance of societies and cultures.
Social anxiety disorder (SAD): A condition marked by acute fear of social situations which lead to worry and diminished day to day functioning.
Social cognition: The study of how people think about the social world.
Social constructivism: Social constructivism proposes that knowledge is first created and learned within a social context and is then adopted by individuals.
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 referencing: This refers to the process whereby individuals look for information from others to clarify a situation, and then use that information to act. Thus, individuals will often use the emotional expressions of others as a source of information to make decisions about their own behavior.
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.
Soma: Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
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.
Specific abilities: Cognitive abilities that contain an appreciable component of g or general ability, but also contain a large component of a more content-focused talent such as mathematical, spatial, or verbal ability; patterns of specific abilities channel development down different paths as a function of an individual’s relative strengths and weaknesses.
Specific vulnerabilities: How our experiences lead us to focus and channel our anxiety.
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.
Standardize: Assessments that are given in the exact same manner to all people . With regards to intelligence tests standardized scores are individual scores that are computed to be referenced against normative scores for a population (see “norm”).
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.
Stereotype Content Model: Stereotype Content Model shows that social groups are viewed according to their perceived warmth and competence.
Stereotype threat: The phenomenon in which people are concerned that they will conform to a stereotype or that their performance does conform to that stereotype, especially in instances in which the stereotype is brought to their conscious awareness.
Stereotypes: Our general beliefs about the traits or behaviors shared by group of people.
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.
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.
Synapse: Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Synapses: 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 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.
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: 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.
Tertiary education: Education or training beyond secondary school, usually taking place in a college, university, or vocational training program.
Thought-action fusion: The tendency to overestimate the relationship between a thought and an action, such that one mistakenly believes a “bad” thought is the equivalent of a “bad” action.
Threshold of excitation: Specific membrane potential that the neuron must reach to initiate an action potential.
Transfer-appropriate processing: A principle that states that memory performance is superior when a test taps the same cognitive processes as the original encoding activity.
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.
Under-determined or misspecified causal models: Psychological frameworks that miss or neglect to include one or more of the critical determinants of the phenomenon under analysis.
Universalism: Universalism proposes that there are single objective standards, independent of culture, in basic domains such as learning, reasoning, and emotion that are a part of all human experience.
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).
Vicarious reinforcement: Learning that occurs by observing the reinforcement or punishment of another person.
Working memory: The ability to maintain information over a short period of time, such as 30 seconds or less.
Working memory: The form of memory we use to hold onto information temporarily, usually for the purposes of manipulation.