R

random assignment: the assignment of subjects to experimental and control conditions so that each subject is as likely to be assigned to one condition as to another. (49)

random sampling: the selection of a sample from a population so that each member of the population has an equal chance of being included. (43)

range a statistic: representing the difference between the highest and lowest scores in a set of scores. (54, 646)

rank-ordering: rating individuals according to their standing in comparison to one another, from best to worst. (661)

rating scale: any scale used for rating people or items. (661)

rational-emotive behavior therapy (R-E-B-T): a type of cognitive therapy, developed by Albert Ellis, that treats psychological disorders by forcing the client to give up irrational beliefs. (529)

rationalism: the philosophical position that true knowledge comes through correct reasoning. (5)

ratio scale: a scale of measurement that indicates the ratio of scores to one another. (641)

reality principle: the process by which the ego directs the individual to express sexual and aggressive impulses in socially acceptable ways. (444)

reciprocal determinism: Bandura's belief that personality traits, environmental factors, and overt behavior affect each other. (458)

reflex: an automatic, involuntary motor response to sensory stimulation. (68)

relaxation response: a variation of transcendental meditation in which the individual may repeat a sound other than a mantra. (218)

release theory: the theory that humor is amusing when it relieves one's sexual or aggressive anxiety. (422)

reliability: the extent to which a test gives consistent results. (45)

REM sleep: the stage of sleep associated with rapid eye movements, an active brain-wave pattern, and vivid dreams. (201)

replication: the repetition of a research study, usually with some alterations in its subjects, methods, or setting, to determine whether the principles derived from that study hold up under similar circumstances. (35)

representativeness heuristic: in decision making, the assumption that a small sample is representative of its population. (323)

repression: the process by which emotionally threatening experiences are banished from the conscious mind to the unconscious mind. (288)

resting potential: the electrical charge of a neuron when it is not firing a neural impulse. (70)

reticular formation: a diffuse network of neurons, extending from the hindbrain through the midbrain and into the forebrain, that helps maintain vigilance and an optimal level of brain arousal. (81)

retina: the light-sensitive inner membrane of the eye that contains the receptor cells for vision. (157)

retrieval: the recovery of information from memory. (273)

retroactive interference: the process by which new memories interfere with the ability to remember old memories. (287)

rods receptor: cells of the retina that play an important role in night vision and peripheral vision. (157)

S

saccadic movements: continuous small darting movements of the eyes that bring new portions of scenes into focus on the foveae. (159)

sample: a group of subjects selected from a population. (43)

scatter plot: a graph of a correlational relationship. (650)

schema: a mental model incorporating the characteristics of particular persons, objects, events, or situations. (118)

schema theory: the theory that long-term memories are stored as parts of schemas, which are cognitive structures that organize knowledge about events or objects. (281)

schizophrenia: a class of psychological disorders characterized by grossly impaired social, emotional, cognitive, and perceptual functioning. (501)

school psychology: the field that applies psychological principles to improving the academic performance and social behavior of students in elementary, junior high, and high schools. (22)

scientific method: a source of knowledge based on the assumption that knowledge comes from the objective, systematic observation and measurement of particular variables and the events they affect. (35)

scientific paradigm: a model that determines the appropriate goals, methods, and subject matter of a science. (15)

sclera: the tough, white outer membrane of the eye. (156)

seasonal affective disorder: a mood disorder in which severe depression arises during a particular season, usually the winter. (494)

secondary reinforcer: in operant conditioning, a neutral stimulus that becomes reinforcing after being associated with a primary reinforcer. (246)

self-actualization: in Maslow's theory, the individual's predisposition to try to fulfill her or his potentials. (462)

self-efficacy: in Bandura's theory, a person's belief that she or he can perform behaviors that are necessary to bring about a desired outcome. (458)

self-fulfilling prophecy: the tendency for one person's expectations to influence another person to behave in accordance with them. (599)

self-perception theory: Daryl Bem's theory that when we are unsure of our attitudes we infer them from our own behavior. (610)

self-serving bias: the tendency to make dispositional attributions for one's successes and situational attributions for one's failures. (597)

semanticity: the characteristic of language marked by the use of symbols to convey thoughts in a meaningful way. (326)

semantic memory: the subsystem of declarative memory that contains general information about the world. (280)

semantic network theory: the theory that memories are stored as nodes interconnected by links that represent their relationships. (281)

semantics: the study of how language conveys meaning. (329)

semicircular canals: the curved vestibular organs of the inner ear that detect movements of the head in any direction. (186)

sensate focusing: a sex therapy technique that at first involves nongenital caressing and gradually progresses to sexual intercourse. (390)

sensation: the process that detects stimuli from the body or surroundings. (152)

sensation seeking: the extent to which an individual seeks sensory stimulation. (397)

sensorimotor stage: the Piagetian stage, from birth through the second year, during which the infant learns to coordinate sensory experiences and motor behavior. (118)

sensory adaptation: the tendency of the sensory receptors to respond less and less to a constant stimulus. (154)

sensory deprivation: the prolonged withdrawal of normal levels of external stimulation. (396)

sensory memory: the stage of memory that briefly, for at most a few seconds, stores exact replicas of sensations. (273)

sensory neuron: a neuron that sends messages from sensory receptors to the central nervous system. (68)

sensory receptors: specialized cells that detect stimuli and convert their energy into neural impulses. (152)

sensory transduction: the process by which sensory receptors convert stimuli into neural impulses. (152)

serial-position effect: the superiority of immediate recall for items at the beginning and end of a list. (284)

serial processing: the processing of information one step at a time. (326)

set point: a specific body weight that the brain tries to maintain through the regulation of diet, activity, and metabolism. (381)

sexual dysfunction: a chronic problem at one or more phases of the sexual response cycle. (390)

sexual orientation: one's sexual attraction toward persons of either one's own sex or the opposite sex. (391)

sexual response: cycle during sexual activity, the phases of excitement, plateau, orgasm, and resolution. (388)

shape constancy: the perceptual process that makes an object appear to maintain its normal shape regardless of the angle from which it is viewed. (170)

shaping: an operant conditioning procedure that involves the positive reinforcement of successive approximations of an initially improbable behavior to eventually bring about that behavior. (247)

short-term memory: the stage of memory that can store a few items of unrehearsed information for up to about 20 seconds. (273)

signal-detection theory: the theory holding that the detection of a stimulus depends on both the intensity of the stimulus and the physical and psychological state of the individual. (153)

simple phobia: a phobia of a specific object or situation. (487)

size constancy: the perceptual process that makes an object appear to remain the same size despite changes in the size of the image it casts on the retina. (169)

skepticism: an attitude that doubts all claims not supported by solid research evidence. (34)

Skinner box: an enclosure that contains a bar or key that can be pressed to obtain food or water, and that is used to study operant conditioning in rats, pigeons, or other small animals. (246)

skin senses: the senses of touch, temperature, and pain. (182)

sleep apnea: a condition in which a person awakens repeatedly in order to breathe. (206)

smooth pursuit movements: eye movements that track objects. (158)

social attachment: a strong emotional relationship between an infant and a caregiver. (121)

social clock: the major events that typically occur at certain times in the typical life cycle in a given culture. (130)

social cognition: the process of perceiving, interpreting, and predicting social behavior. (594)

social-comparison theory: the theory that happiness is the result of estimating that one's life circumstances are more favorable than those of others. (420)

social-cultural perspective: the psychological viewpoint that favors the scientific study of human behavior in its social-cultural context. (18)

social facilitation: the improvement in a person's task performance when in the presence of other people. (615)

social learning theory: a theory of gender-role development that assumes that people learn social behaviors mainly through observation and mental processing of information. (125, 262)

social loafing: a decrease in the individual effort exerted by group members when working together on a task. (616)

social phobia: a phobia of situations that involve public scrutiny. (488)

social psychology: the field that studies how people affect one another's thoughts, feelings, and behaviors. (21, 594)

social schema: a cognitive structure comprising the presumed characteristics of a role, an event, a person, or a group. (598)

social-skills training: a form of behavioral group therapy that improves the client's social relationships by improving her or his interpersonal skills. (535)

social support: the availability of support from other people, whether tangible or intangible. (573)

sociobiology: the study of the hereditary basis of human and animal social behavior. (377)

soma: the cell body, the neuron's control center. (68)

somatic nervous system: the division of the peripheral nervous system that sends messages from the sensory organs to the central nervous system and messages from the central nervous system to the skeletal muscles. (67)

somatoform disorder: a psychological disorder characterized by physical symptoms in the absence of disease or injury. (490)

somatosensory cortex: the area of the parietal lobes that processes information from sensory receptors in the skin. (85, 182)

somatotype: a person's body type, whether ectomorphic (thin), mesomorphic (muscular), or endomorphic (fat). (466)

sound localization: the process by which the individual determines the location of a sound. (178)

spatial frequency filter theory: the theory that visual perception depends on the detection and analysis of variations in patterns of light and dark. (166)

spinal cord: the structure of the central nervous system that is located in the spine and plays a role in body reflexes and in communicating information between the brain and the peripheral nervous system. (67)

split-brain research: research on hemispheric specialization that studies individuals whose corpus callosum has been severed. (99)

spontaneous recovery: 1. in classical conditioning, the reappearance after a period of time of a conditioned response that has been subjected to extinction. 2. in operant conditioning, the reappearance after a period of time of a behavior that has been subjected to extinction. (240, 252)

spontaneous remission: the improvement of some persons with psychological disorders without their undergoing formal therapy. (548)

sport psychology: the field that applies psychological principles to help amateur and professional athletes improve their performance. (22, 401)

SQ3R method: a study technique in which the student surveys, questions, reads, recites, and reviews course material. (292)

standard deviation: a statistic representing the degree of dispersion of a set of scores around their mean. (54, 648)

standardization: 1. a procedure assuring that a test is administered and scored in a consistent manner. 2. a procedure for establishing test norms by giving a test to large samples of people who are representative of those for whom the test is designed. (44)

state-dependent memory: the tendency for recall to be best when one's emotional or physiological state is the same during the recall of a memory as it was during the encoding of that memory. (291)

statistical significance: a low probability (usually less than 5 percent) that the results of a research study are due to chance factors rather than to the independent variable. (56, 653)

statistics: mathematical techniques used to summarize research data or to determine whether the data support the researcher's hypothesis. (35, 640)

stereochemical theory: the theory of olfaction and gustation that assumes that receptors are stimulated by molecules of particular sizes and shapes. (180)

stereotype: a social schema that incorporates characteristics, which may be positive or negative, supposedly shared by almost all members of a group. (598)

stimulants: psychoactive drugs that increase central nervous system activity. (222)

stimulus discrimination: in classical conditioning, giving a conditioned response to the conditioned stimulus but not to stimuli similar to it. (240)

stimulus generalization: in classical conditioning, giving a conditioned response to stimuli similar to the conditioned stimulus. (239)

storage: the retention of information in memory. (273)

stress: the physiological response of the body to physical and psychological demands. (558)

stress-inoculation training: a type of cognitive therapy, developed by Donald Meichenbaum, that helps clients change their pessimistic thinking into more positive thinking when in stressful situations. (527)

stressor: a physical or psychological demand that induces physiological adjustment. (558)

structuralism: the early school of psychology that sought to identify the components of the conscious mind. (9)

subject bias: the tendency of people who know they are subjects in a study to behave in a way other than they normally would. (49)

subliminal perception: the unconscious perception of stimuli that are too weak to exceed the absolute threshold for detection. (226)

subliminal psychodynamic activation: the use of subliminal messages to stimulate unconscious fantasies. (229)

substantia nigra: a midbrain structure that promotes smooth voluntary body movements. (81)

superego: in Freud's theory, the part of the personality that acts as a moral guide telling us what we should and should not do. (444)

surface structure: the word arrangements used to express thoughts. (329)

survey: a set of questions related to a particular topic of interest administered to a sample of people through an interview or questionnaire. (42)

sympathetic nervous system: the division of the autonomic nervous system that arouses the body to prepare it for action. (67)

synapse: the junction between a neuron and a gland, muscle, sensory organ, or another neuron. (72)

synaptic transmission: the conveying of a neural impulse between a neuron and a gland, muscle, sensory organ, or another neuron. (72)

synesthesia: the process in which an individual experiences sensations in one sensory modality that are characteristic of another. (224)

syntax: the rules that govern the acceptable arrangement of words in phrases and sentences. (328)

systematic desensitization: a form of counterconditioning that trains the client to maintain a state of relaxation in the presence of imagined anxiety-inducing stimuli. (524)

T

taste buds: structures lining the grooves of the tongue that contain the taste receptor cells. (181)

tectum: a midbrain structure that mediates reflexive responses to visual and auditory stimuli. (81)

telegraphic speech: speech marked by reliance on nouns and verbs, while omitting other parts of speech, including articles and prepositions. (330)

temperament: a person's characteristic emotional state, first apparent in early infancy and possibly inborn. (466)

temporal lobe: a lobe of the cerebral cortex responsible for processing hearing. (86)

teratogen: a noxious substance, such as a virus or drug, that can cause prenatal defects. (114)

testes: the male gonads, which secrete hormones that regulate the development of the male reproductive system and secondary sex characteristics. (78)

thalamus: a forebrain structure that acts as a sensory relay station for taste, body, visual, and auditory sensations. (82)

theory: an integrated set of statements that summarizes and explains research findings, and from which research hypotheses may be derived. (38)

theory of multiple intelligences: Howard Gardner's theory of intelligence, which assumes that the brain has evolved separate systems for seven kinds of intelligence. (362)

thinking: the mental manipulation of words and images, as in concept formation, problem solving, and decision making. (310)

timbre: the subjective experience that identifies a particular sound and corresponds most closely to the mixture of sound waves composing it. (177)

tip-of-the-tongue phenomenon: the inability to recall information that one knows has been stored in long-term memory. (289)

token economy: an operant conditioning procedure that uses tokens as positive reinforcers in programs designed to promote desirable behaviors, with the tokens later used to purchase desired items or privileges. (256, 526)

trait: a relatively enduring, cross-situationally consistent personality characteristic that is inferred from a person's behavior. (453)

transactional analysis (TA): a form of psychoanalytic group therapy, developed by Eric Berne, that helps clients change their immature or inappropriate ways of relating to other people. (535)

transcendental meditation (TM): a form of meditation in which the individual relaxes and repeats a sound called a mantra for two 20-minute periods a day. (218)

transcutaneous electrical nerve stimulation (TENS): the use of electrical stimulation of sites on the body to provide pain relief, apparently by stimulating the release of endorphins. (184)

transfer: bringing back to the job environment what was learned in training. (664)

transformational grammar: the rules by which languages generate surface structures from deep structures, and deep structures from surface structures. (329)

transitive inference: the application of previously learned relationships to infer new relationships. (120)

transsexualism: a condition in which a genetic male or female has the gender identity of the opposite sex. (391)

trephining: an ancient technique in which sharp stones were used to chip holes in the skull, possibly to let out evil spirits that supposedly caused abnormal behavior. (518)

trial and error: an approach to problem solving in which the individual tries one possible solution after another until one works. (314)

triarchic theory of intelligence: Robert Sternberg's theory of intelligence, which assumes that there are three main kinds of intelligence: componential, experiential, and contextual. (361)

trichromatic theory: the theory that color vision depends on the relative degree of stimulation of red, green, and blue receptors. (162)

trust versus mistrust: Erikson's developmental stage in which success is achieved by having a secure social attachment with a caregiver. (121)

t test: a statistical technique used to determine whether the difference between two sets of scores is statistically significant. (653)

turnover: the ratio of new employees to established employees. (666)

two-factor theory: the theory that emotional experience is the outcome of physiological arousal and the attribution of a cause for that arousal. (429)

tympanic membrane: the eardrum; a membrane separating the outer and middle ears that vibrates in response to sound waves that strike it. (175)

Type A behavior: a syndromeÑmarked by impatience, hostility, and extreme competitivenessÑthat is associated with the development of coronary heart disease. (586)

U

unconditioned response (UCR): in classical conditioning, an unlearned, automatic response to a particular unconditioned stimulus. (237)

unconditioned stimulus (UCS): in classical conditioning, a stimulus that automatically elicits a particular unconditioned response. (237)

unconscious mind: the level of consciousness that contains thoughts, feelings, and memories that influence us without our awareness and that we cannot become aware of at will. (229)

underextension: the tendency to apply a word to fewer objects or actions than it actually represents. (330)

undifferentiated schizophrenia: a catchall category for cases that do not fall neatly into any single kind of schizophrenia. (503)

V

valance: how much value an individual places on a particular outcome. (664)

validation: a process that determines whether tests are accurate predictors of job success. (659)

validity: the extent to which a test measures what it is supposed to measure. (45)

variable: an event, behavior, or characteristic that has two or more values. (46)

variable-interval schedule of reinforcement: a partial schedule of reinforcement that provides reinforcement for the first desired response made after varying, unpredictable lengths of time. (250)

variable-ratio schedule of reinforcement: a partial schedule of reinforcement that provides reinforcement after varying, unpredictable numbers of desired responses. (250)

variance: a measure based on the average deviation of a set of scores from their group mean. (54, 647)

vestibular sense: the sense that provides information about one's position in space and helps in the maintenance of balance. (186)

visible spectrum: the portion of the electromagnetic spectrum that we commonly call light. (155)

vision: the sense that detects objects by the light reflected from them into the eyes. (155)

visual cortex: the area of the occipital lobes that processes visual input. (86, 160)

visual illusion: a misperception of physical reality usually caused by the misapplication of visual cues. (171)

volley theory: the theory of pitch perception that assumes that sound waves of particular frequencies induce auditory neurons to fire in volleys, with one volley following another. (177)

W

Wada test: a technique in which a cerebral hemisphere is anesthetized to assess hemispheric specialization. (97)

Weber's law: the principle that the amount of change in stimulation needed to produce a just noticeable difference is a constant proportion of the original stimulus. (154)

Wernicke's area: the region of the temporal lobe responsible for the comprehension of speech. (88)

Y

Yerkes-Dodson law: the principle that the relationship between arousal and performance is best represented by an inverted U-shaped curve. (394)