2“Mind Reading”As pollsters often demonstrate during elections, reading minds, whether of voters or the person next to you, is close to impossible. However, as this ScienCentral News video explains, scientists are one step closer to reading our thoughts.
3Thinking and Intelligence GerdGigerenzer has written about fears that he calls dread risksDread risks can result when events with dire consequences receive a lot of publicity, even when the publicized events have a low probability of recurringThe resulting fears can profoundly affect reasoning and decision making9/11 caused many more people to fear flying even though the number of people who die in car accidents every year far exceeds the number who die in airline disasters or hijackings
48.1 What Is Thought?Distinguish between analogical and symbolic representations.Describe the defining attribute, prototype, and exemplar models of concepts.Discuss the positive and negative consequences of using schemas and scripts.4
5Thinking Is the Manipulation of Mental Representations The field of cognitive psychology is the study of thought. It was originally based on two ideas:The brain represents informationThinking is the mental manipulation of these representationsOur thoughts consist of mental representations of the objects and information that we encounter in our environmentsCognition includes thinking and the understandings that result from thinking5
6Thinking Involves Two Types of Representations Analogical representations: mental representations that have some of the physical characteristics of objects, e.g. mapsWhen we think of an object, we often bring to mind a visual image, or analogical representation, of the objectPause and think about a lemon: What form did your “lemon” thought take?Symbolic representations: abstract mental representations that do not correspond to the physical features of objects or ideas, e.g. words or ideasNeural activity occurs when we look at objects, and it can be reactivated when we recall the objects
7FIGURE 8.3 Analogical Representations and Symbolic Representations (a) Analogical representations, such as this picture of a violin, have some characteristics of the objects they represent. (b) Symbolic representations, such as the word violin, are abstract and do not have relationships to the objects.
8Mental Maps Combine Representation Mental maps can include both analogical and symbolic representationsSymbolic representations can lead to errors, because we can represent only a limited range of knowledge analogically and thus use memory shortcuts unconsciouslyWhich is farther east, San Diego, California, or Reno, Nevada?Which is farther north, Seattle, Washington, or Montreal, Canada?
9FIGURE 8.4 Try for Yourself: Conceptual Mental Maps
10FIGURE 8.4 Try for Yourself: Conceptual Mental Maps
11Concepts Are Symbolic Representations Grouping things based on shared properties, categorization, reduces the amount of knowledge we must hold in memory and is therefore an efficient way of thinkingMuch of our knowledge of the world is based on concepts, or categories of items organized around common themesconcept: a mental representation that groups or categorizes objects, events, or relations around common themes
12FIGURE 8.5 Categorization We group objects into categories according to the objects’ shared properties.
13Defining Attribute Model Defining attribute model: In this way of thinking about concepts, a category is characterized by a list of features that determine if an object is a memberFor example, a “bachelor” is characterized by being unmarried and maleThe model suggests:membership within a category is on an all-or-none basis;all of a given category’s attributes are equally important in defining that category;all members of a category are equal in category membershipWe often make exceptions in our categorizations, and some attributes are more important for defining membershipThe boundaries between categories are much fuzzier than the defining attribute model suggestsIs every unmarried male a “bachelor”?
14FIGURE 8.6 The Defining Attribute Model In the defining attribute model, concepts are organized hierarchically. That is, they can be subordinate or superordinate to each other. For example, horns and stringed instruments are subordinate categories of the superordinate category of musical instruments.
15Prototype ModelPrototype model: Within each category, there is a best example—a prototype—for that categoryOne positive feature of the prototype model is that it allows for flexibility in the representation of conceptsOne drawback related to such flexibility is that a particular prototype can be chosen for different reasons: Life experiences, culture, or location can influence the prototype for a category
16FIGURE 8.7 The Prototype Model According to the prototype model, some items within a group or class are more representative (or prototypical) of that category than are other items within that group or class.
17FIGURE 8.8 Try for Yourself: The Prototype Model of Concepts
18Exemplar ModelExemplar model: All members of a category are examples (exemplars); together they form the concept and determine category membershipIt assumes that, through experience, people form a fuzzy representation of a concept because there is no single representation of any conceptIt accounts for the observation that some category members are more prototypical than others: The prototypes are simply members we have encountered more oftenHow would you explain the difference between a dog and a cat to someone who has never seen either? Most dogs bark, but a dog is still a dog if it does not bark
19FIGURE 8.9 The Exemplar Model The exemplar model holds that all members of a category are exemplars. For example, even this strange-looking feline is an exemplar of the category cats. (This cat happens to be a brown tortie white and tabby sphinx.)
20Schemas Organize Useful Information about Environments Schemas are cognitive structures that help us perceive, organize, and process informationScripts are schemas that dictate appropriate behavior.What we view as appropriate is shaped by cultureSchemas and scripts are adaptive in that they enable us to make quick judgments with little effortWhat sequence of events does the script going to the movies include? How would you feel if a stranger sat next to you in the theater, or started talking?
21FIGURE 8.12a Script Theory of Schemas According to this theory, we tend to follow general scripts of how to behave in particular settings. (a) At the movies, we expect to buy a ticket or print one if we bought it online. The cost of the ticket might depend on the moviegoer’s age and the time of day.
22FIGURE 8.12b Script Theory of Schemas According to this theory, we tend to follow general scripts of how to behave in particular settings. (b) Next, we might buy a snack before selecting a seat. Popcorn is a traditional snack at movie theaters. Caviar is not.
23FIGURE 8.12c Script Theory of Schemas According to this theory, we tend to follow general scripts of how to behave in particular settings. (c) If we are part of a couple or group, we expect to sit with the other person in that couple or the people in the group. Although quiet talking might be appropriate before the movie, most of us expect talking to cease once the feature begins.
24Schemas Organize Useful Information about Environments Schemas and scripts may lead us to think and act in stereotypical waysstereotypes: cognitive schemas that allow for easy, fast processing of information about people based on their membership in certain groupsGender roles are the prescribed behaviors for females and males and represent a type of schema that operates at the unconscious levelThe schemas and scripts that children learn are likely to affect their behavior when they are older
25FIGURE 8.13 Scientific Method: Study of Preschoolers’ Use of Cigarettes and Alcohol while Role-Playing as Adults
26Psychology: Knowledge You Can Use— How Can Dating Scripts Help Me Navigate in My Romantic Life? According to Amiraian and Sobal (2009), “Dating scripts are shared cognitive representations of likely sequences of dating events and sets of appropriate dating behaviors based on social norms and previous experiences that direct decisions and behavior on dates.”Knowing how a date is likely to unfold removes some of the ambiguity of an eventFollowing a generally accepted script and behaving consistently with a set of culturally accepted rules helps manage the impressions that other people form about youLet your values and beliefs guide your behavior; collaborate on a date that feels right to you
288.2 How Do We Make Decisions and Solve Problems? Distinguish between deductive and inductive reasoning.Distinguish between normative and descriptive models of decision making.Explain how heuristics, framing, and affective forecasting influence decision making.Review strategies that facilitate insight and problem solving.
298.2 How Do We Make Decisions and Solve Problems? Thinking enables us to do the following:reasoning: using information to determine if a conclusion is valid or reasonabledecision making: attempting to select the best alternative among several optionsproblem solving: finding a way around an obstacle to reach a goal29
30People Use Deductive and Inductive Reasoning When drawing conclusions, we engage in deductive and inductive reasoningErrors, such as making biased choices in what evidence to consider, can lead to false conclusions in both deductive and inductive reasoning tasks
31FIGURE 8.14 Deductive Reasoning, Inductive Reasoning, Decision Making, and Problem Solving
32Deductive ReasoningIn deductive reasoning, you use logic to draw specific conclusions under certain assumptions (premises)deductive reasoning: using general rules to draw conclusions about specific instancesIn research, a deductive reasoning task is often expressed as a syllogism, e.g. If A is true, then B is trueWe can come up with a valid but incorrect conclusion, however, if the premises use terms inconsistently or ambiguouslyConsider the following:Nothing is better than a piece of warm apple pieA few crumbs of bread are better than nothingTherefore, a few crumbs of bread are better than warm apple pieHow might prior beliefs or schemas interfere with deductive reasoning?
33Inductive ReasoningInductive reasoning involves reasoning from the specific to the generalinductive reasoning: using specific instances to draw conclusions about general rulesFor example, if your Italian friend is fashionable, you may induce that Italians in general are fashionableHow might inductive reasoning lead to erroneous conclusions?
34Inductive and Deductive Reasoning Combined You always bump into your roommate at the coffee shopThrough inductive reasoning, you believe she really likes coffeeTherefore you decide through deductive reasoning to get her a Starbucks gift card for her birthday
35Reasoning and the Scientific Method The use of the scientific method to discover general principles is one example of inductive reasoningThe scientific method dictates that scientists meet certain standards when inducing general principles from several specific instancesThese standards are designed to guard against biases in inductive reasoningIn day-to-day life, however, we may be more likely to reach inappropriate conclusions when reasoning about general principles from everyday circumstancesPeople are strongly influenced by anecdotal reports
36Decision Making Often Involves Heuristics In their research on decision making, psychologists have studied normative models and descriptive models:Normative models of decision making view people as optimal decision makersDescriptive models account for actual behaviorExpected utility theory is one normative model of how we should make decisions by considering the possible alternatives and choosing the most desirable oneResearch has demonstrated, however, that we are not always rational in making decisions
37Decision Making Often Involves Heuristics Tversky and Kahneman identified several common heuristicsheuristics: shortcuts (rules of thumb or informal guidelines) used to reduce the amount of thinking that is needed to make decisionsHeuristic thinking often occurs unconsciously and allows us to free up some cognitive resourcesHeuristic thinking can be adaptive in that it allows us to decide quickly rather than weighing all the evidence each time we have to decideHeuristics can also result in biases, which may lead to errors or faulty decisionsAn algorithm is a procedure that, if followed correctly, will always yield the correct answer
38Framing EffectsHow information is presented can alter how people perceive itframing: the effect of presentation on how information is perceived
40Framing EffectsTo account for framing’s effects, Kahneman and Tversky came up with prospect theory, a major theory in decision makingProspect theory has two main components:a person’s wealth affects his or her choicesloss aversion: Because losses feel much worse than gains feel good, a person will try to avoid situations that involve losses
41FIGURE 8.17 Loss AversionHow happy would you feel if someone walked over to you right now and handed you $1,000? How bad would you feel if someone took $1,000 from your checking account? Potential losses affect decision making more than potential gains do. In your opinion, why do people dislike losses so much?
42Critical Thinking Skills: Understanding How Heuristics Can Affect Your Thinking Prototypes are readily available in memory. We tend to rely on prototypes in making decisionsavailability heuristic: making a decision based on the answer that most easily comes to mindWe base decisions on the extent to which each option reflects what we already believe about a situationrepresentativeness heuristic: placing a person or object in a category if that person or object is similar to one’s prototype for that categoryHeuristics can lead to faulty reasoning if you fail to take other information into account, such as the base rate (how frequently an event occurs)Once we know that such shortcuts can lead us to make faulty judgments, we can use heuristics carefully as we seek to make rational decisions
43FIGURE 8.16 The Availability Heuristic at Work If you are like most people, you thought of words with r as the first letter (such as right and read). Then you thought of words with r as the third letter (such as care and sir). Because words with r at the beginning came most easily to mind, you concluded that r is more often the first letter of a word. R is much more likely, however, to be the third letter in a word.
44Affective Forecasting Gilbert and Wilson have found that people are not good at affective forecasting, or predicting how they will feel about a future eventPeople tend to overestimate the extent to which negative events will affect them in the futureWe engage in adaptive strategies — such as rationalizing why an event happened and minimizing the event’s importance — to cope with negative events.People seem unaware that they can find positive outcomes from tragic events, and typically when considering a hypothetical aversive event, they overestimate the misery and underestimate how well they will cope with the eventAffective forecasting can also influence our perceptions of positive events:How would you feel if you won an Olympic medal?Now, compare winning the silver medal vs. the gold.
45“Drinking vs. Talking”You “walk the line” during a sobriety test because you shouldn’t drive if you’ve drunk so much you can’t walk in a straight line. But as this ScienCentral News video explains, research suggests that talking while driving may be just as dangerous.
46FIGURE 8.19 Affective Forecasting Mardy Fish (left) was disappointed when he won the silver medal for tennis at the 2004 Olympics. At any point in your life, have you been disappointed by an outcome that someone else might have viewed as success? How did the circumstances contribute to your disappointment?
47The Paradox of ChoicePsychological reactance occurs when we are told what to do and what not to do; we react by wanting to do exactly what is forbidden to us even if we had no strong preferences before our choices were restrictedIyengar and Lepper’s study indicates that having many possibilities can make it difficult to choose one itemAccording to psychologist Barry Schwartz, the consequence of nearly unlimited choice makes some people miserable and may help explain the increase in clinical depression. He divides the world into satisficersand maximizers.Satisficerslook around until they find something that most closely matches what they want and buy it, without worrying about whether better or cheaper products are availableMaximizers always seek to make the best possible choices. They hesitate in making decisions, and they feel paralyzed by indecision when they have to select between equally attractive choices. As a result, they generally are more disappointed with their decisions and more likely to experience regret
48FIGURE 8.21 Way Too Much Choice? Spam—a canned, precooked meat product—tends to divide people into lovers and haters. Haters of Spam would most likely not have a problem passing this display quickly. Suppose you were a lover of Spam. How would Barry Schwartz recommend that you deal with the many varieties of Spam (and related products) offered here?
49Problem Solving Achieves Goals A person has a problem when he or she has no simple and direct means of attaining a particular goalTo solve the problem, the person must use knowledge to determine how to move from the current state to the goal stateOften, the person must devise strategies to overcome obstaclesHow the person thinks about the problem can help or hinder that person’s ability to find solutions
50Organization of Subgoals One approach to the study of problem solving is to identify people’s steps in solving particular problemsBreaking down a problem into subgoals is an important component of problem solvingWhen you are facing a complex problem, identifying the appropriate steps or subgoals and their order can be challenging
52Sudden InsightUnconscious processes sometimes lead to objectively better solutions than conscious processes doInsight: the sudden realization of a solution to a problemKöhler demonstrated that chimpanzees, as well as humans, have insightful momentsMaier’s study with the string and pliers provides an example of how insight can be achieved when a problem initially seems unsolvableHow we view or represent a problem can significantly affect how easily we solve itA saying like think outside the box embodies ideas about insight; however, it may not be very useful without hints for how to get started
53Changing Representation to Overcome Obstacles In problem solving we often need to revise a mental representation to overcome an obstaclerestructuring: a new way of thinking about a problem that aids its solution; representing the problem in a novel wayThe new view reveals a solution that was not visible under the old problem structureAttempt to solve Sheerer’s Nine Dot Problem:How can you “think outside the box” to connect all nine dots using at most four straight lines, without lifting the pencil off the page (see next slide)?
55Changing Representation to Overcome Obstacles In trying to solve a problem, we commonly think back to how we have solved similar problemsmental sets: problem-solving strategies that have worked in the pastFunctional fixedness (mental representations about the typical functions of particular objects) can also create difficulties in problem solvingTo overcome this kind of obstacle, the problem solver needs to reinterpret the object’s potential function, e.g. Duncker’s candle challenge
56FIGURE 8.24 Luchins’s Mental Set In 1942, the Gestalt psychologist Abraham Luchins demonstrated a classic example of a mental set.He asked participants to measure out specified amounts of water, such as 100 cups, using three jars of different sizes.Say that jar A held 21cups, jar B held 127 cups, and jar C held 3 cups.The solution to this problem was to fill jar B, use jar A to remove 21 cups from jar B’s 127 cups, then use jarC to remove 3 cups of water twice, leaving 100 cups in jar B.The structure to the solution is B – A – 2(C). Participants were given many of these problems. In each problem, the jar sizes and goal measurements differed, but the same formula applied.Then participants were given another problem: They were given jar A, which held 23 cups; jar B, which held 49 cups; and jar C, which held 3 cups.They were asked to measure out 20 cups.Even though the simplest solution was to fill jar A and use jar C to remove 3 cups from jar A’s 23, participants usually came up with a much more complicated solution that involved all three jars.Having developed a mental set of using three jars in combination to solve this type of problem, they had trouble settling on the simpler solution of using only two jars.Surprisingly, when given a problem with a simple solution for which the original formula did not work, many participants failed to solve the problem most efficiently.
58Conscious Strategies Two examples of conscious strategies: working backward: When the appropriate steps for solving a problem are not clear, proceeding from the goal state to the initial state can help yield a solutionfinding an appropriate analogy: Using a strategy that works in one context can help to solve a problem that is structurally similar with analogous constraintsAnalogous solutions work only if we recognize the similarities between the problem we face and those we have solved
59“Writer’s Block”Anyone who has tried to write and ended up staring at a blank page knows the pain of writer’s block. But for some, this barrier is devastating. As this ScienCentral News video reports, researchers have found some nontraditional ways to unlock extreme writer’s block.
608.3 How Do We Understand Intelligence? Identify common measures of intelligence.Discuss the validity of measures of intelligence.Review theory and research related to general intelligence, fluid intelligence, crystallized intelligence, multiple intelligences, and emotional intelligence.Discuss the relationship between intelligence and cognitive performance.Summarize research examining genetic and environmental influences on intelligence.Discuss sex and race differences in intelligence.Define stereotype threat.
618.3 How Do We Understand Intelligence? Individuals differ in terms of intelligence just as they differ physically and in terms of their personalities.intelligence: the ability to use knowledge to reason, make decisions, make sense of events, solve problems, understand complex ideas, learn quickly, and adapt to environmental challengesPsychologists consider two aspects when measuring intelligence: They study the ways that knowledge and its applications in everyday life translate into intelligence, and they examine the degree to which intelligence is determined by genes and by environment.61
62“Brainy Brains”The size of your brain doesn’t necessarily determine how smart you are; your IQ, brain researchers say, is more influenced by how your brain thickens and thins when you’re a kid. This ScienCentral News video has more.
63Intelligence Is Assessed with Psychometric Tests The psychometric approach to measuring intelligence focuses on how people perform on standardized testsSome psychometric tests focus on achievement;other psychometric tests focus on aptitudeBinet proposed that intelligence is best understood as a collection of high-level mental processesPsychometric tests of general intelligence include the Stanford-Binet test, which measures intelligence using the intelligence quotient, or IQ scoreThe Wechsler Adult Intelligence Scale has two parts: verbal and performance
64Intelligence Quotient Binet introduced the important concept of mental age:mental age: an assessment of a child’s intellectual standing compared with that of same-age peers; determined by comparing the child’s test score with the average score for children of each chronological ageThe intelligence quotient (IQ) was developed by the psychologist Wilhelm Stern:intelligence quotient (IQ): an index of intelligence computed by dividing a child’s estimated mental age by the child’s chronological age, then multiplying this number by 100IQ in the adult range is measured in comparison with the average adult and not with adults at different agesAcross large groups of people, the distribution of IQ scores forms a bell curve, or normal distribution;most people are close to the average
65FIGURE 8.27 The Distribution of IQ Scores IQ is a score on a normed test of intelligence. That is, one person’s score is relative to the scores of the large number of people who already took the test. And as discussed in Chapter 2, the statistical concept of standard deviation indicates how far people are from an average. The standard deviation for most IQ tests is 15. The average, or mean, is 100. As shown in this bell curve, approximately 68 percent of people fall within 1 standard deviation of the mean (they score from 85 to 115). Just over 95 percent of people fall within 2 standard deviations (they score from 70 to 130).
66Validity of TestingThe overall evidence indicates that IQ is a fairly good predictor of life outcomes, e.g. doing well at schoolData suggests modest correlations between IQ and work performance, IQ and income, IQ and jobs requiring complex skillsIQ scores typically predict only about 25 percent of the variation in performance at either school or workIQ may be important, but it is only one of the factors that contributes to success in the classroom, the workplace, and life generally; additional factors include background, self- control, motivation, and willingness to work
67Cultural BiasOne important criticism of intelligence tests is that they may penalize people for belonging to particular cultures or particular groupsA person’s exposure to mainstream language and culture affects which meaning of a word comes most quickly to mind, if the person knows the meaning at all:What does it mean when someone says something is “rad”?Most measures of IQ reflect values of what is considered important in modern Western cultureWhat is adaptive in one society is not necessarily adaptive in othersOne approach to dealing with cultural bias is to use items that do not depend on language, e.g. performance measures on the Wechsler Adult Intelligence Scale (WAIS)
68FIGURE 8.28 Removing Bias from Tests According to the creators of this test, the task is not culturally biased. Do you agree? Why or why not?
69Critical Thinking Skill: Recognizing and Avoiding Reification Reification is the tendency to think about complex traits as though they have a single cause and an objective reality, e.g. the complex concept of intelligenceIntelligence is a multifaceted concept defined within a context, not just by a score in isolationFor example, if English is your native language but you speak enough Spanish to take an intelligence test in Spanish, you probably would not expect the resulting IQ to reflect your intelligence accuratelyCritical thinkers avoid treating an abstract concept as though it has a tangible reality. They recognize the complexity in complex concepts
70General Intelligence Involves Multiple Components An early line of research examined the correlations among intelligence test items using factor analysisIn this statistical technique, items similar to one another are clustered, and the clusters are referred to as factorsCharles Spearman found that most intelligence test items tended to cluster as one factorSpearman viewed general intelligence, or g, as a factor that contributes to performance on any intellectual taskgeneral intelligence (g): the idea that one general factor underlies intelligence
71FIGURE 8.29 General Intelligence as a Factor As depicted in this cluster of overlapping circles and ovals, Spearman viewed g as a general factor in intelligence. This underlying factor influences an individual’s specific abilities related to intelligence.
72The Importance of gResearch has shown that g influences important life outcomes, such as by predicting performance in school and at workLow g is related to early death from causes including heart disease, diabetes, stroke, Alzheimer’s disease, traffic accidents, and drowningsHowever, researchers from the United Kingdom and Finland found that lower socioeconomic status may be the most important predictor of early mortalityA number of theorists have proposed that g’s main value is in allowing people to adapt quickly to environmental challengesAlthough most psychologists agree that some form of g exists, they also recognize that intelligence comes in various forms
73Fluid Versus Crystallized Intelligence Raymond Cattell (1971) proposed that g consists of two types of intelligence:fluid intelligence: intelligence that reflects the ability to process information, particularly in novel or complex circumstances, e.g. reasoningcrystallized intelligence: intelligence that reflects both the knowledge one acquires through experience and the ability to use that knowledgeDistinguishing between fluid intelligence and crystallized intelligence is somewhat analogous to distinguishing between working memory (more like fluid intelligence) and long-term memory (more like crystallized intelligence)Crystallized intelligence grows steadily throughout the adult years, while fluid intelligence declines steadily
74Multiple Intelligences Howard Gardner proposed a theory of multiple intelligences:multiple intelligences: the idea that there are different types of intelligence that are independent of one anotherProposed intelligences include: musical, bodily-kinesthetic, linguistic, mathematical/logical, spatial, intrapersonal, and interpersonal (social understanding) intelligenceThere are still no standardized ways to assess many of Gardner’s intelligences and some psychologists argue these are special talentsSternberg theorized that there are three types of intelligence:Analytical intelligence is similar to that measured by psychometric tests— being good at problem solving and other academic challenges;Creative intelligence involves the ability to gain insight and solve novel problems—to think in new and interesting ways;Practical intelligence refers to dealing with everyday tasks, such as knowing whether a parking space is large enough for your vehicleEvidence for the existence of such multiple intelligences is presented in the cases of many phenomenally successful public figures who did not excel academically, e.g. Bill Gates dropped out of college
75Emotional Intelligence Emotional intelligence (EI) was conceived by the psychologists Peter Salovey and John Mayer and popularized by the science writer Daniel Golemanemotional intelligence (EI): a form of social intelligence that emphasizes the abilities to manage, recognize, and understand emotions and use emotions to guide appropriate thought and actionRegulating our moods, resisting impulses and temptations, and controlling our behaviors are all important components of EIEmotional intelligence is correlated with the quality of social relationshipsSome critics have questioned whether EI really is a type of intelligence or whether it stretches the definition of intelligence too far
76Intelligence Is Associated with Cognitive Performance Galton believed that intelligence was related to the speed of neural responses and the sensitivity of the sensory/perceptual systems, and he speculated that intelligent people have larger, more efficient brainsOther psychologists believe intelligence is supported by low-level cognitive processes, such as mental processing, working memory, and attention
77Speed of Mental Processing People who score higher on intelligence tests respond more quickly and consistently on reaction time testsA test of simple reaction time might require a person to press a computer key as quickly as possible whenever a stimulus appears on the screenFurther support for the relation between general intelligence and speed of mental processing comes from inspection time tests:If a stimulus is presented and then covered up, how much viewing time does a particular person need to answer a question about the stimulus?By measuring the electrical activity of brains in response to the presentation of stimuli, researchers have found that highly intelligent people’s brains work faster than less intelligent people’s brainsThe relation between general intelligence and mental speed appears to be correlated with the greater longevity of people with high IQsThe relationship between reaction time and longevity was somewhat stronger than the relationship between scores on standardized intelligence tests and longevity
79Working MemoryGeneral intelligence scores are closely related to working memory but are not identicalStudies differentiate between simple tests of memory span and memory tests that require some form of secondary processingMemory tests that have dual components, however, show a strong relation between working memory and general intelligenceThe link between working memory and general intelligence may be attention, or the ability to pay attention
81Brain Structure and Function Many studies have documented a relationship between head circumference, which researchers use to estimate brain size, and scores on intelligence testsStudies using magnetic resonance imaging have found a small but significant correlation between the size of selected brain structures and scores on intelligence testsThese findings are correlations, however, so we cannot infer that brain size necessarily causes differences in intelligenceDifferent kinds of intelligence seem to be related to the sizes of certain brain regions. These regions include areas associated with working memory, planning, reasoning, and problem solvingGeneral intelligence appears to be associated mainly with increased cortex sizeThese findings are consistent with evidence that injury to the frontal lobes causes impairments in fluid intelligence but not in crystallized intelligence
82FIGURE 8.34 Extraordinary Brain Sandra Witelson with Einstein’s brain in her lab at McMaster University. Does the size of Einstein’s parietal lobe indicate that larger brains are smarter? Why or why not?
83SavantsSavants have minimal intellectual capacities in most domains, but at a very early age each savant shows an exceptional ability in some “intelligent” processA savant’s exceptional ability may be related to math, music, or artThe combination of prodigious memory and the inability to learn seemingly basic tasks is a great mystery; this rare combination adds a dimension to our understanding of intelligence
84FIGURE 8.35 Stephen Wiltshire Despite his autism, Stephen Wiltshire had published a book of his remarkably accurate, expressive, memory-based drawings by the time he was a young teenager. Here, in October 2010, he holds his drawing of an architectural site in London, England. Wiltshire observed the site briefly, then completed the picture largely from memory.
85Genes and Environment Influence Intelligence Even if intelligence has a genetic component, the way intelligence becomes expressed is affected by various situational circumstancesFor example, the capacity for having a large vocabulary is considerably heritable, but every word in a person’s vocabulary is learned in an environmentInstead of seeking to demonstrate whether nature or nurture is the more important factor, psychologists try to identify how each of these crucial factors contributes to intelligence
86Behavioral GeneticsNumerous behavioral genetics studies have made clear that genes help determine intelligence—but the extent to which genes do so is difficult to determineBehavioral geneticists study the genetic basis of behaviors and traits such as intelligence; they use twin and adoption studies to estimate the extent to which particular traits are heritableEven when raised apart, twins who have inherited an advantage might receive some social multiplier, an environmental factor or an entire environment, that increases what might have started as a small advantageSuppose twins have inherited a higher than average verbal ability? Adults who notice this ability might read to them more often and give them more books
87FIGURE 8.36 Genes and Intelligence This graph represents average IQ correlations from family, adoption, and twin study designs. As shown by the red and blue bars on the left, siblings raised together show more similarity than siblings raised apart. As indicated by the relations between parent and offspring (P-O) in the red and blue bars, a parent and child are more similar when the parent raises the child than when the child is raised by someone else. As shown by the red and blue bars on the right, the highest correlations are found among monozygotic twins, whether they are raised in the same household or not. Overall, the greater the degree of genetic relation, the greater the correlation in intelligence.
88Environmental Factors Prenatal and postnatal factors, such as poor nutrition, can affect brain development and result in lower intelligenceResearch from numerous laboratories has shown that enriched environments enhance learning and memoryThe implication is that environment influences how genes involved in brain development are expressedSchooling encourages the development of children’s brains and cognitive capacities and therefore fosters intelligenceThe dramatic rise of IQ scores during the last century has been called the Flynn effect after James R. Flynn, the researcher who first described itSince genes cannot have changed much during this period, the increase must be due to environmental factors
89“Go Play Outside”Feel like you’re suffering from brain drain and can’t concentrate? Psychologists have found that taking some time to interact with nature, even in cold weather; can make you a bit smarter.
90FIGURE 8.37 Environmental Impacts Within each of these planters, differences in the plants are likely due to genes. But note how different the plants are as a whole between one planter and the other. Those differences likely result from the environmental differences between the planters. (a) This planter has provided an impoverished environment. The poor conditions have negatively affected growth and development. (b) This planter has provided an enriched environment. The proper resources have contributed to robust growth and development.
91FIGURE 8.38 Birth Weight and Intelligence Among children of normal birth weight, mean IQ scores increase with weight.
92Group Differences in Intelligence Have Multiple Determinants Which is the smarter sex?Using IQ scores to determine which is the smarter sex does not work because most of the commonly used intelligence tests were written in ways that would avoid creating an overall sex difference in IQUsing only tests that had not deliberately eliminated sex differences, Jensen found no evidence for sex differences in the mean level of g or in the variability of g. Males, on average, excel on some factors; females on others
93Group Differences in Intelligence Have Multiple Determinants Are there intelligence differences based on race?The most controversial aspect of intelligence testing over the last century has been the idea that genetics can explain overall differences in intelligence scores between racial groupsIn a 1969 paper, Jensen created a firestorm of controversy by asserting that African Americans are, on average, less intelligent than European AmericansGiven the importance of intelligence to educational and career attainment, claims that some groups are superior to others require close scrutiny, and it is important to discuss controversial and sensitive topics with an eye to being as fair to all sides as possible
94Group Differences in Intelligence Have Multiple Determinants Whether the effects of race are real or not, it is not scientifically appropriate to conclude that genes cause differences between groups if there are any environmental differences between those groupsResearch has demonstrated that stereotype threat may be reduced by informing people of the negative consequences of stereotype threat, having people focus on positive aspects of their lives, and bolstering people’s peer relations and social connections.stereotype threat: apprehension about confirming negative stereotypes related to one’s own group
95FIGURE 8.40 Stereotype Threat Stereotype threat may lead black students to perform poorly on some standardized tests.
96FIGURE 8.41 Stereotype Threat Counteracted Stereotype threat can be counteracted when people are warned about it.