Chapter 8 Objectives---Learning AP PSYCH Chapter 8, 10, 11 Review Packet 1. Define learning, and identify two forms of learning. Learning is a relatively permanent change in an organism s behavior due to experience. Nature s most important gift to us may be our adaptability our capacity to learn new behaviors that enable us to cope with ever-changing experiences. We learn by association; our mind naturally connects events that occur in sequence. The events linked in associative learning may be two stimuli (as in classical conditioning) or a response and a rewarding or punishing stimulus (as in operant conditioning). In observational learning, we learn by viewing others experiences and examples. 2. Define classical conditioning and behaviorism, and describe the basic components of classical conditioning. Pavlov explored the phenomenon we call classical conditioning, in which organisms associate stimuli and thus associate events. This laid the foundation for John Watson s behaviorism, which held that psychology should be an objective science that studied only observable behavior. Pavlov would repeatedly present a neutral stimulus (such as a tone) just before an unconditioned stimulus (US), such as food, which triggered the unconditioned response (UR) of salivation. After several repetitions, the tone alone (now the conditioned stimulus [CS]) began triggering a conditioned response (CR), salivation. Unconditioned means unlearned ; conditioned means learned. Thus, a UR is an event that occurs naturally in response to some stimulus. A US is something that naturally and automatically triggers the unlearned response. A CS is an originally neutral stimulus that, through learning, comes to be associated with some unlearned response. A CR is the learned response to the originally neutral but now conditioned stimulus. 3. Describe the timing requirements for the initial learning of a stimulus-response relationship. Responses are acquired that is, initially learned best when the CS is presented half a second before the US. This finding demonstrates how classical conditioning is biologically adaptive. 4. Summarize the processes of extinction, spontaneous recovery, generalization, and discrimination. Extinction refers to the diminishing of a conditioned response when the conditioned stimulus occurs repeatedly without the unconditioned stimulus. Spontaneous recovery is the reappearance, after a pause, of an extinguished conditioned response. Generalization is the tendency to respond to stimuli that are similar to the conditioned stimulus. Discrimination is the learned ability to distinguish between a CS and other irrelevant stimuli. 5. Discuss the survival value of generalization and discrimination. Generalization has survival value because it extends a learned response to other stimuli in a given category, for example, fleeing from all dangerous animals. Discrimination has survival value because it limits our learned responses to appropriate stimuli, for example, fleeing from a rampaging lion but not from a playful kitten. 6. Discuss the importance of cognitive processes in classical conditioning. Research indicates that, for many animals, cognitive appraisals are important for learning. That is, thoughts and perceptions are important to the conditioning process. For example, animals appear capable of learning when to expect an unconditioned stimulus, and their awareness of the link between stimuli and responses can weaken associations. 7. Describe some of the ways that biological predispositions can affect learning by classical conditioning. The early behaviorists view that any natural response could be conditioned to any neutral stimulus has given way to the understanding that each species is biologically prepared to learned associations that enhance its survival. Thus, humans more easily learn to fear snakes and spiders than to fear flowers. Rats develop aversions to tastes but not to sights or sounds. Conditioning occurs best when the CS and the US have just the sort of relationship that would lead a scientist to conclude that the CS causes the US.
8. Summarize Pavlov s contribution to our understanding of learning. Pavlov taught us that principles of learning apply across species and that classical conditioning is one way that virtually all organisms learn to adapt to their environment. Pavlov also demonstrated that significant psychological phenomena can be studied objectively. Finally, Pavlov taught us that conditioning principles have important applications such as how to treat fear. 9. Describe some uses of classical conditioning to improve human health and well-being. Classical conditioning principles provide important insights into drug abuse and how it may be overcome. Classical conditioning works on the body s disease-fighting immune system. For example, when a particular taste accompanies a drug that influences immune responses, the taste by itself may come to produce those immune responses. Watson s Little Albert study demonstrated how classical conditioning may underlie specific fears. Today, psychologists use extinction procedures to control our less adaptive emotions and condition new responses to emotion-arousing stimuli. 10. Identify the two major characteristics that distinguish classical conditioning from operant conditioning. The two characteristics that help us distinguish the two forms of conditioning are the following: In classical conditioning, the organism learns associations between events that it does not control, and responses are automatic. In operant conditioning, the organism learns associations between its behavior and resulting events; the organism operates on the environment. 11. State Thorndike s law of effect, and explain its connection to Skinner s research on operant conditioning. Edward Thorndike s law of effect states that rewarded behavior is likely to recur. Using this as his starting point, Skinner explored the principles and conditions of learning through operant conditioning, in which behavior operates on the environment to produce rewarding or punishing stimuli. Skinner used an operant chamber (Skinner box) in his pioneering studies with rats and pigeons. 12. Describe the shaping procedure, and explain how it can increase our understanding of what nonverbal animals and babies can discriminate. In his experiments, Skinner used shaping, a procedure in which reinforcers, such as food, guide an animal s natural behavior toward a desired behavior. By rewarding responses that are ever closer to the final desired behavior (successive approximations), and ignoring all other responses, researchers can gradually shape complex behaviors. Because nonverbal animals and babies can respond only to what they perceive, their reactions demonstrate which events they can discriminate. 13. Compare positive and negative reinforcement, and give one example each of a primary reinforcer, a conditioned reinforcer, an immediate reinforcer, and a delayed reinforcer. A reinforcer is any event that increases the frequency of a preceding response. Reinforcers can be positive (presenting a pleasant stimulus after a response) or negative (reducing or removing an unpleasant stimulus). Primary reinforcers, such as food when we are hungry, are innately satisfying. Conditioned reinforcers, such as cash, are satisfying because we have learned to associate them with more basic rewards. Immediate reinforcers, such as the nicotine addict s cigarette, offer immediate payback. Delayed reinforcers, such as a weekly paycheck, require the ability to delay gratification. 14. Discuss the strengths and weaknesses of continuous and partial (intermittent) reinforcement schedules, and identify four schedules of partial reinforcement. When the desired response is reinforced every time it occurs, continuous reinforcement is involved. Learning is rapid but so is extinction if rewards cease. Partial (intermittent) reinforcement produces slower acquisition of the target behavior than does continuous reinforcement, but the learning is
more resistant to extinction. Reinforcement schedules may vary according to the number of responses rewarded or the time gap between responses. Fixed-ratio schedules reinforce behavior after a set number of responses; variable-ratio schedules provide reinforcers after an unpredictable number of responses. Fixed-interval schedules reinforce the first response after a fixed time interval and variable-interval schedules reinforce the first response after varying time intervals. 15. Discuss the ways negative punishment, positive punishment, and negative reinforcement differ, and list some drawbacks of punishment as a behavior-control technique. Punishment attempts to decrease the frequency of a behavior. Positive punishment administers an undesirable consequence, for example, spanking; negative punishment withdraws something desirable, such as taking away a favorite toy. Negative reinforcement (such as taking an aspirin) removes something undesirable (a headache) to increase the frequency of a behavior. Punishment is not simply the logical opposite of reinforcement, for it can have several undesirable side effects, including suppressing rather than changing unwanted behaviors, teaching aggression, creating fear, and fostering feelings of helplessness. 16. Explain how latent learning and the effect of external rewards demonstrate that cognitive processing is an important part of learning. Rats exploring a maze seem to develop a mental representation (a cognitive map) of the maze even in the absence of reward. Their latent learning becomes evident only when there is some incentive to demonstrate it. Research indicates that people may come to see rewards, rather than intrinsic interest, as the motivation for performing a task. Again, this finding demonstrates the importance of cognitive processing in learning. By undermining intrinsic motivation, the desire to perform a behavior for its own sake, rewards can carry hidden costs. Extrinsic motivation is the desire to perform a behavior because of promised rewards or threats of punishment. A person s interest often survives when a reward is used neither to bribe nor coerce but to signal a job well done. 17. Explain how biological predispositions place limits on what can be achieved through operant conditioning. As with classical conditioning, an animal s natural predispositions constrain its capacity for operant conditioning. Biological constraints predispose organisms to learn associations that are naturally adaptive. Training that attempts to override these tendencies will probably not endure, because the animals will revert to their biologically predisposed patterns. 18. Describe the controversy over Skinner s views of human behavior. Skinner has been criticized for repeatedly insisting that external influences, not internal thoughts and feelings, shape behavior and for urging the use of operant principles to control people s behavior. Critics argue that he dehumanized people by neglecting their personal freedom and by seeking to control their actions. Skinner countered: People s behavior is already controlled by external reinforcers, so why not administer those consequences for human betterment? 19. Describe some ways to apply operant conditioning principles at school, in sports, at work, and at home. Operant principles have been applied in a variety of settings. For example, in schools, on-line testing systems and interactive student software embody the operant ideal of individualized shaping and immediate reinforcement. In sports, coaches can build players skills and self-confidence by rewarding small improvements. In the workplace, positive reinforcement for jobs well done has boosted employee productivity. At home, people s use of energy has been decreased by altering the consequences and providing feedback. Parents can reward behaviors that are desirable and not those that are undesirable. To reach our personal goals, we can monitor and reinforce our own desired behaviors and cut back on incentives as the behaviors become habitual. 20. Identify the major similarities and differences between classical and operant conditioning. Both classical and operant conditioning are forms of associative learning. They both involve acquisition, extinction, spontaneous recovery, generalization, and discrimination. Both classical and operant conditioning are influenced by biological and cognitive predispositions. The two
forms of learning differ in an important way. In classical conditioning, organisms associate different stimuli that they do not control and respond automatically. In operant conditioning, organisms associate their own behaviors with their consequences. 21. Describe the process of observational learning, and explain the importance of the discovery of mirror neurons. Among higher animals, especially humans, learning does not occur through direct experience alone. Observational learning also plays a part. The process of observing and imitating a specific behavior is often called modeling. Mirror neurons, located in the brain s frontal lobes, demonstrate a neural basis for observational learning. 22. Describe Bandura s findings on what determines whether we will imitate a model. Bandura found that we are likely to imitate actions that go unpunished. We tend to imitate models that we perceive as similar to us, successful, or admirable. 23. Discuss the impact of prosocial modeling. Prosocial models have prosocial effects. People who show nonviolent, helpful behavior prompt similar behavior in others. Models are most effective when their actions and words are consistent. Exposed to a hypocrite, children tend to imitate the hypocrisy by doing what the model did and saying what the model says. 24. Explain why correlations cannot prove that watching violent TV causes violent behavior, and cite some experimental evidence that helps demonstrate a cause-effect link. Correlational studies that link viewing violence with violent behavior do not indicate the direction of influence. Those who behave violently may enjoy watching violence on TV, or some third factor may cause observers both to behave violently and to prefer watching violent programs. To establish cause and effect, researchers have designed experiments in which some participants view violence and others do not. Later, given an opportunity to express violence, the people who viewed violence tend to be more aggressive and less sympathetic. In addition to imitating what they see, observers may become desensitized to brutality, whether on TV or in real life.
Chapter 10 Objectives---Thinking & Language 1. Define cognition. Cognition refers to the mental activities associated with thinking, knowing, remembering, and communicating. Cognitive psychologists study these activities including the logical and illogical ways we solve problems and make decisions. 2. Describe the roles of categories, hierarchies, definitions, and prototypes in concept formation. To think about the countless events, objects, and people in our world, we organize them into mental groupings called concepts. We create mental hierarchies of groupings by clustering them into categories based on their similarities, and then subdividing those categories into increasingly smaller and more detailed units. Although we form some concepts by definition for example, a triangle has three sides more often we form a concept by developing a prototype, a mental image or best example of a particular category. For example, a robin more closely resembles our bird category than does a goose. The more closely objects match our prototype of a concept, the more readily we recognize them as examples of a concept. 3. Compare algorithms and heuristics as problem-solving strategies, and explain how insight differs from both of them. We approach some problems through trial and error, attempting various solutions until stumbling upon one that works. For other problems we may follow a methodical rule or step-by-step procedure called an algorithm. Because algorithms can be laborious, we often rely instead on simple strategies called heuristics. Speedier than algorithms, heuristics are also more error-prone. Sometimes, however, we are unaware of using any problem-solving strategy; the answer just comes to us as a sudden flash of inspiration or insight. 4. Contrast confirmation bias and fixation, and explain how they can interfere with effective problem solving. A major obstacle to problem solving is our eagerness to search for information that confirms our ideas, a phenomenon known as confirmation bias. This can mean that once people form a wrong idea, they will not budge from their illogic. Another obstacle to problem solving is fixation the inability to see a problem from a fresh perspective. The tendency to repeat solutions that have worked in the past is a type of fixation called mental set. It may interfere with our taking a fresh approach when faced with problems that demand an entirely new solution. Our tendency to perceive the functions of objects as fixed and unchanging is called functional fixedness. Perceiving and relating familiar things in new ways is an important aspect of creative problem solving. 5. Contrast the representativeness and availability heuristics, and explain how they can cause us to underestimate or ignore important information. The representativeness heuristic involves judging the likelihood of things in terms of how well they seem to represent particular prototypes. If something matches our mental representation of a category, that fact usually overrides other considerations of statistics or logic. The availability heuristic operates when we base our judgments on the availability of information in our memories. If instances of an event come to mind readily, we presume such events are common. Both heuristics enable us to make snap judgments. However, these quick decisions sometimes lead us to ignore important information or to underestimate the chances of something happening. 6. Describe the drawbacks and advantages of overconfidence in decision making. Overconfidence, the tendency to overestimate the accuracy of our knowledge and judgments, can have adaptive value. People who err on the side of overconfidence live more happily and find it easier to make tough decisions. At the same time, failing to appreciate one s potential for error when making military, economic, or political judgments can have devastating consequences.
7. Describe how others can use framing to elicit from us the answers they want. The same issue presented in two different but logically equivalent ways can elicit quite different answers. This framing effect suggests that our judgments and decisions may not be well reasoned, and that those who understand the power of framing can use it to influence important decisions for example, by wording survey questions to support or reject a particular viewpoint. 8. Explain how our preexisting beliefs can distort our logic. We show a belief bias in our reasoning, accepting as more logical those conclusions that agree with our beliefs. Similarly, we more easily see the illogic of conclusions that run counter to our beliefs. This belief bias can lead us to accept invalid conclusions and to reject valid ones. 9. Describe the remedy for the belief perseverance phenomenon We exhibit belief perseverance, clinging to our ideas in the face of contrary evidence because the explanation we accepted as valid lingers in our minds. Once beliefs are formed and justified, it takes more compelling evidence to change them than it did to create them. The best remedy for this form of bias is to make a deliberate effort to consider evidence supporting the opposite position. 10. Describe the smart thinker s reaction to using intuition to solve problems. Although human intuition is sometimes perilous, it can be remarkably efficient and adaptive. Moreover, it feeds our creativity, our love, and our spirituality. Smart intuition is born of experience. As we gain expertise in a field, we become better at making quick, adept judgments. Experienced nurses, firefighters, art critics, and hockey players learn to size up a situation in an eye blink. Smart thinkers will welcome their intuitions but also check them against available evidence in an effort to avoid overconfidence and illogical thinking. 11. Describe the basic structural units of a language. Language is our way of combining words to communicate meaning. Spoken language is built of basic speech sounds, called phonemes; elementary units of meaning, called morphemes; and words. Finally, language must have a grammar, a system of rules that enables us to communicate with others. Semantics refers to the rules we use to derive meaning from the morphemes, and syntax refers to the rules we use to order words into sentences. 12. Trace the course of language acquisition from the babbling stage through the two-word stage. Children s language development mirrors language structure by moving from simplicity to complexity. Beginning at about 4 months, infants enter a babbling stage in which they spontaneously utter various sounds at first unrelated to the household language. By about age 10 months, a trained ear can identify the language of the household by listening to an infant s babbling. Around the first birthday, most children enter the one-word stage, and by their second birthday, they are uttering two-word sentences. This twoword stage is characterized by telegraphic speech. This soon leads to their uttering longer phrases (there seems to be no three-word stage ), and by early elementary school, they understand complex sentences. 13. Discuss Skinner s and Chomsky s contributions to the nature-nurture debate over how children acquire language, and explain why statistical learning and critical periods are important concepts in children s language learning. The debate between the behaviorist view of the malleable organism and the view that each organism comes biologically prepared to learn certain associations surfaces again in theories of language development. Representing the nurture side of the argument, behaviorist B. F. Skinner argued that we learn language by the familiar principles of association (of sights of things with sounds of words), imitation (of words and syntax modeled by others), and reinforcement (with success, smiles and hugs after saying something right). Challenging this claim, and representing the nature side of the debate, Noam Chomsky notes that children are biologically prepared to learn words and use grammar (they are born with what Chomsky called a language acquisition device already in place). He argues that children acquire untaught words and grammar at too fast a rate to be explained solely by learning principles. Moreover, there is a sort of universal grammar that underlies all human language. Cognitive neuroscientists suggest
that the statistical learning that occurs during life s first few years is critical for the mastery of grammar. Skinner s emphasis on learning helps explain how infants acquire their language as they interact with others. Chomsky s emphasis on our builtin readiness to learn grammar helps explain why preschoolers acquire language so readily and use grammar so well. Nature and nurture work together. 14. Summarize Whorf s linguistic determinism hypothesis and comment on its standing in contemporary psychology. Although Whorf s linguistic determinism hypothesis suggests that language determines thought, it is more accurate to say that language influences thought. Language expresses our thoughts and different languages can embody different ways of thinking. Many bilinguals report that they have a different sense of self, depending on which language they use. At the same time, those without our words for shapes and colors perceive them much as we do. Given the subtle influence of words on thinking, we ought to choose our words carefully..studies of the effects of the generic pronoun he and the ability of vocabulary enrichment to enhance thinking reveal the influence of words. Some ideas, such as the ability to perceive and remember different colors, do not depend on language. We might say that our thinking influences our language, which then affects our thoughts. 15. Discuss the value of thinking in images. We often think in images. In remembering how we do things, for example, turning on the water in the bathroom, we use procedural memory a mental picture of how we do it. Artists, composers, poets, mathematicians, athletes, and scientists all find images to be helpful. Researchers have found that thinking in images is especially useful for mentally practicing upcoming events and can actually increase our skills. 16. List five cognitive skills shared by the great apes and humans. Animals, especially the great apes, show remarkable capacities for thinking. Both great apes and humans (1) form concepts, (2) display insight, (3) use and create tools, (4) transmit cultural innovations, and (5) have a theory of mind, including the capacity for reasoning, self-recognition, empathy, intuition, and understanding another s mind. 17. Outline the arguments for and against the idea that animals and humans share the capacity for language. Animals obviously communicate. Velvet monkeys have different alarm cries for different predators, whales communicate with clicks and wails, and bees communicate the location of food through an intricate dance. Several teams of psychologists have taught various species of apes, including a number of chimpanzees, to communicate with humans by signing or by pushing buttons wired to a computer. Apes have developed considerable vocabularies. They string words together to express meaning and have taught their skills to younger animals. Skeptics point out important differences between apes and humans facilities with language, especially in their respective abilities to master the verbal or signed expression of complex rules of syntax. Nevertheless, studies reveal that apes have considerable ability to think and communicate.
Chapter 11 Objectives---Intelligence 1. Discuss the difficulty of defining intelligence, and explain what it means to reify intelligence. As a socially constructed concept, intelligence varies from culture to culture. Thus, most psychologists now define intelligence as the ability to learn from experience, solve problems, and adapt to new situations. To reify something is to view an abstract, immaterial concept as if it were a concrete thing. Thus, to reify IQ is to treat the intelligence quotient as if it were a fixed and objectively real trait like height. 2. Present arguments for and against considering intelligence as one general mental ability. Psychologists agree that people have specific abilities, such as verbal and mathematical aptitudes. However, they debate whether a general intelligence (g) factor runs through them all, as proposed by Charles Spearman. Factor analysis has identified several clusters of mental abilities, including verbal intelligence, spatial ability, and reasoning ability. Still, there seems to be a tendency for those who excel in one of the clusters to score well on others, as suggested by the results of L. L. Thurstone s ranking of subjects primary mental abilities. Some psychologists today agree with Spearman s notion that we have a common level of intelligence that can predict our abilities in all other academic areas. 3. Compare Gardner s and Sternberg s theories of intelligence. Evidence that brain damage may diminish one ability but not others, as well as studies of savant syndrome, led Howard Gardner to propose his theory of multiple intelligences. These include linguistic, logical-mathematical, musical, spatial, bodily kinesthetic, intrapersonal, interpersonal, and natural. Robert Sternberg also proposes a triarchic theory of multiple intelligences in which he distinguishes among analytical, practical, and creative intelligences. 4. Describe the four aspects of emotional intelligence, and discuss criticisms of this concept. Distinct from academic intelligence is emotional intelligence. The three components of emotional intelligence are (1) the ability to perceive emotions (to recognize them in faces, music, and stories), (2) to understand emotions (to predict them and how they change and blend), (3) to manage emotions (to know how to express them in varied situations), and (4) to use emotions to enable adaptive or creative thinking. Those who are emotionally smart often succeed in careers, marriages, and parenting where other academically smarter (but emotionally less intelligent) people fail. Critics of the idea of emotional intelligence argue that we stretch the idea of intelligence too far when we apply it to emotion. 5. Identify the factors associated with creativity, and describe the relationship between creativity and intelligence. In general, people with high intelligence scores do well on creativity tests. But beyond a score of about 120, the correlation between intelligence scores and creativity disappears. Studies suggest five other components of creativity: expertise, imaginative thinking skills, venturesome personality, intrinsic motivation, and a creative environment. The brain regions supporting the convergent thinking tested by intelligence tests (requiring a single correct answer) differ from those supporting the divergent thinking that imagines multiple solutions to a problem (such as words beginning with the letter s). 6. Describe the relationship between intelligence and brain anatomy. Several studies report a positive correlation (+.40) between brain size (adjusted for body size) and intelligence score. Moreover, as adults age, brain size and nonverbal intelligence test scores fall in concert. Other studies suggest that highly educated people die with more synapses. The direction of the relationship between brain size and intelligence remains unclear. Larger brain size may enable greater intelligence but it is also possible that greater intelligence leads to experiences that exercise the brain and build more connections, thus increase its size. Or some third factor may be at work. Some evidence suggests that highly intelligent people differ in their neural plasticity. 7. Discuss findings on the correlations between perceptual speed, neural processing speed, and intelligence. People who score high on intelligence tests tend to retrieve information from memory more quickly. Research also suggests that the correlation between intelligence score and the speed of taking in information tends to be about +.4 to +.5. Those who perceive quickly are especially likely to score higher
on tests based on perceptual rather than verbal problem solving. The brain waves of highly intelligent people register a simple stimulus such as a flash of light more quickly and with greater complexity. The evoked brain response also tends to be slightly faster when people with high intelligence rather than low intelligence scores perform a simple task, such as pushing a button when an X appears on the screen. As yet, psychologists have no firm idea of why fast reactions on simple tasks should predict intelligence test performance. 8. Define intelligence test, and discuss the history of intelligence testing. Psychologists define an intelligence test as a method for assessing an individual s mental aptitudes and comparing them with those of others, using numerical scores. The modern intelligencetesting movement started more than a century ago when French psychologist Alfred Binet began assessing intellectual abilities. Together with Theodore Simon, Binet developed an intelligence test containing questions that assessed mental age and helped predict children s future progress in the Paris school system. The test sought to identify French school children needing special attention. Binet and Simon made no assumption about the origin of intelligence. Lewis Terman believed that intelligence was inherited. Like Binet, he believed that his test, the Stanford-Binet, could help guide people toward appropriate opportunities. William Stern derived the intelligence quotient, or IQ, for Terman s test. The IQ was simply a person s mental age divided by chronological age multiplied by 100. During the early part of the twentieth century, intelligence tests were sometimes used in ways that, in hindsight, even their designers regretted to document a presumed innate inferiority of certain ethnic and immigrant groups. 9. Distinguish between aptitude and achievement tests, and describe modern tests of mental abilities such as the WAIS. Aptitude refers to the capacity to learn and thus aptitude tests are those designed to predict a person s future performance. Achievement tests are designed to assess what a person has learned. The Wechsler Adult Intelligence Test Revised (WAIS) is the most widely used intelligence test. It consists of 11 subtests and yields not only an overall intelligence score but also separate verbal comprehension, perceptual organization, working memory, and processing speed scores. Striking differences between these scores alert the examiner to possible learning problems or brain disorders. The tests also provide clues to cognitive strengths that a teacher or employer might build on. 10. Discuss the importance of standardizing psychological tests, and describe the distribution of scores in a normal curve. Because scores become meaningful only when they can be compared with others performance, they must be defined relative to a pretested group, a process called standardization. Obviously, the group on which a test is standardized must be representative of those who will be taking the test in the future. For example, Terman recognized that a scale standardized on Parisians did not provide a satisfactory standard for evaluating Americans. Thus, he revised Binet s test and standardized the new version by testing 2300 native-born, white Americans of differing socioeconomic levels. Standardized test results typically form a normal distribution, a bell-shaped pattern of scores that forms the normal curve. Most scores cluster around average, and increasingly fewer are distributed at the extremes. Intelligence test scores form such a curve but in the past six decades, the average score has risen 27 points, a phenomenon known as the Flynn effect. 11. Explain what it means to say that a test is reliable. Reliability refers to the extent to which a test yields consistent scores. Consistency may be assessed by comparing scores on two halves of the test, on alternative forms, or on retesting. A test can be reliable but not valid. 12. Explain what it means to say a test is valid, and describe two types of validity. Validity refers to the extent to which a test measures or predicts what it is supposed to. Content validity is determined by assessing whether the test truly samples the behavior that is of interest. For example, driving tests should measure driving ability. Predictive validity is determined by computing the correlation between test scores and some criterion, that is, some independent measure of what the test aims to assess. Aptitude tests have predictive validity if they can predict future achievement.
13. Describe the stability of intelligence scores over the life span. The stability of intelligence test scores increases with age. By age 4, children s performance on intelligence tests begins to predict their adolescent and adult scores. After about age 7, intelligence scores, though certainly not fixed, stabilize. 14. Discuss the two extremes of the normal distribution of intelligence. At one extreme of the normal distribution are people whose intelligence scores fall below 70. To be labeled as having mental retardation, a child must have both a low test score and difficulty adapting to the normal demands of living independently. Severe mental retardation sometimes results from known physical causes, such as Down syndrome, a disorder attributed to an extra chromosome in the person s genetic makeup. Most mentally challenged adults can, with support, live in mainstream society. At the other extreme are the gifted. Contrary to the popular myth that they are frequently maladjusted, research suggests that high-scoring children are healthy, well adjusted, and academically successful. Controversy surrounds gifted child programs in which the gifted are segregated and given academic enrichment not available to the masses. Critics note that tracking by aptitude sometimes creates a self-fulfilling prophecy: those implicitly labeled ungifted can be influenced to become so. Denying lower-ability students opportunities for enriched education can widen the achievement gap between ability groups and increase their social isolation from one another. 15. Discuss the evidence for the genetic contribution to individual intelligence, and explain what psychologists mean by the heritability of intelligence. Studies of twins, family members, and adopted children together point to a significant genetic contribution to of intelligence scores. For example, the test scores of identical twins reared separately are similar enough to lead one researcher to estimate that about 70 percent of intelligence score variation can be attributed to genetic variation. Furthermore, the most genetically similar people have the most similar scores ranging from +.85 for identical twins raised together, to about +.33 for unrelated individuals raised together. As noted in Chapter 3, heritability refers to the extent to which differences among people are attributable to genes. To say that the heritability of intelligence is 50 percent does not mean that half of an individual s intelligence is inherited. Rather it means that we can attribute to heredity 50 percent of the variation of intelligence among those studied. 16. Discuss the evidence for environmental influences on individual intelligence. Studies of twins, family members, and adopted children also provide evidence for environmental influences on intelligence. The intelligence test scores of fraternal twins raised together are more similar that those of other siblings, and the scores of identical twins raised apart are less similar than the scores of identical twins raised together. Studies of children reared in extremely neglectful or enriched environments also indicate that life experiences significantly influence intelligence test scores. For example, research indicates that schooling and intelligence contribute to each other (and that both enhance later income). 17. Describe ethnic similarities and differences in intelligence test scores, and discuss some genetic and environmental factors that might explain them. African-Americans average about 10 points lower than white Americans on intelligence tests. European New Zealanders outscore native Maori New Zealanders, Israeli Jews outscore Israeli Arabs, and most Japanese outscore the stigmatized Japanese minority. Research suggests that environmental differences are largely responsible for these group differences. Consider: (1) genetics research indicates that the races are remarkably alike under the skin; (2) race is not a neatly defined biological category; (3) Asian students outperform North American students on math achievement and aptitude tests; (4) intelligence test performance of today s better-fed, bettereducated, and more testprepared population exceeds that of the 1930s population by the same margin that the score of the average White today exceeds that of the average Black; (5) white and black infants tend to score equally well on tests measuring preferences for looking at novel stimuli a predictor of future intelligence; and (6) in different eras, different ethnic groups have experienced periods of remarkable achievement.
18. Describe gender differences in abilities. Although gender similarities far outnumber gender differences, we find the differences in abilities more interesting. Research indicates that, compared to boys, girls are better spellers, are more verbally fluent, are better at locating objects and are more sensitive to touch, taste, and color. Boys are more likely than girls to be underachievers, and outperform girls at math problem solving but underperform them in math computation. Women detect emotions more easily than do men. 19. Discuss whether intelligence tests are biased, and describe the stereotype threat phenomenon. Intelligence tests are biased in the sense that they are sensitive to performance differences caused by cultural experience. However, tests are not biased in that they predict as accurately for one group as they do for another. For example, the predictive validity is roughly the same for blacks and whites and for rich and poor. Stereotype threat is a self-confirming concern that one will be evaluated based on a negative stereotype. The phenomenon sometimes appears in intelligence testing among African-Americans and among women of all colors.