Lipscomb Psychology 2301 Chapter 9 Themes and Variations 9E Intelligence

The Bell Curve

For example, recent research suggests that the heritability of intelligence may be notably lower in samples drawn from the lower socioeconomic classes as opposed to higher socioeconomic classes ( Turkheimer et al., 2003). However, heritability estimates for intelligence have largely been based on samples drawn from white, middle-class, North American and European populations (Grigerenko, 2000). Hence, there is doubt about the validity of applying these heritability estimates to other cultural groups. We fill a white sack and a black sack with a mixture of different genetic varieties of corn seed. We make certain that the proportions of each variety of seed are identical in each sack. We then plant the seed from the white sack in fertile Field A, while that from the black sack is planted in barren Field B. We will observe that within Field A, as within Field B, there is considerable variation in the height of individual corn plants. This variation will be due largely to genetic factors (seed differences). We will also observe, however, that the average height of plants in Field A is greater than that in Field B. That difference will be entirely due to environmental factors (the soil). The same is true of IQs: differences in the average IQ of various human populations could be entirely due to environmental differences, even if within each population all variation were due to genetic differences! ( Eysenck & Kamin, 1981) This analogy shows that even if within-group differences in IQ are highly heritable, between-groups differences in average IQ could still be caused entirely by environmental factors ( Block, 2002). For decades, critics of Jensen's thesis have relied on this analogy rather than actual data to make the point that between-groups differences in IQ do not necessarily reflect genetic differences. They depended on the analogy because no relevant data were available. However, the recent discovery of the Flynn effect has provided compelling new data that are directly relevant ( Dickens & Flynn, 2001; Flynn, 2003). Generational gains in IQ scores show that a between-groups disparity in average IQ (in this case the gap is between generations rather than ethnic groups) can be environmental in origin, even though intelligence is highly heritable. The available evidence certainly does not allow us to rule out the possibility that ethnic and cultural disparities in average intelligence are partly genetic. And the hypothesis should not be dismissed without study simply because many people find it offensive or distasteful. However, there are several alternative explanations for the culture gap in intelligence that seem more plausible. Let's look at them. Socioeconomic Disadvantage as an Explanation Claude Steele"I believe that in significant part the crisis in black Americans' education stems from the power of this vulnerability to undercut identification with schooling."Claude Steele© Courtesy of Claude Steele Some theorists have approached the issue by trying to show that socioeconomic disadvantages are the main cause of ethnic differences in average IQ. Many social scientists argue that minority students' IQ scores are depressed because these children tend to grow up in deprived environments that create a disadvantage—both in school and on IQ tests. Obviously, living circumstances vary greatly within ethnic groups, but there is no question that, on the average, whites and minorities tend to be reared in different circumstances. Most minority groups have endured a long history of economic discrimination and are greatly overrepresented in the lower social classes. A lower-class upbringing tends to carry a number of disadvantages that work against the development of a youngster's full intellectual potential ( Bigelow, 2006; Evans, 2004; Lott, 2002; McLoyd, 1998; Noble, McCandliss, & Farah, 2007; Seifer, 2001). In comparison to the middle and upper classes, lower-class children are more likely to come from large families and from single-parent homes. Such factors may often limit the parental attention they receive. Lower-class children also tend to be exposed to fewer books, to have fewer learning supplies, to have less privacy for concentrated study, and to get less parental assistance in learning. Typically, they also have poorer role models for language development, experience less encouragement to work hard on intellectual pursuits, and attend poorer-quality schools that are underfunded and understaffed. Many of these children grow up in crime-, drug-, and gang-infested neighborhoods where it is far more important to develop street intelligence than school intelligence. Some theorists also argue that children in the lower classes are more likely to suffer from malnutrition or to be exposed to environmental toxins ( Brody, 1992). Any of these circumstances could interfere with youngsters' intellectual development ( Bellinger & Adams, 2001; Grantham-McGregor, Ani, & Fernald, 2001). In light of these disadvantages, it's not surprising that average IQ scores among children from lower social classes tend to run about 15 points below the average scores obtained by children from middle-and upper-class homes ( Seifer, 2001; Williams & Ceci, 1997). This is the case even if race is factored out of the picture by studying whites exclusively. Given the effect that social class appears to have on test scores, many researchers argue that ethnic differences in intelligence are really social class differences in disguise. Stereotype Threat as an Explanation Socioeconomic disadvantages probably are a major factor in various minority groups' poor performance on IQ tests. Some theorists, however, maintain that other factors and processes are also at work. For example, Claude Steele (1992, 1997) has argued that negative stereotypes of stigmatized groups' intellectual abilities create feelings of vulnerability in the classroom. These feelings of stereotype threat can undermine group members' performance on tests, as well as other measures of academic achievement. Steele points out that negative stereotypes of stigmatized groups are widely known. He further notes that members of minority groups are keenly aware of any negative stereotypes that exist regarding their intellect. Hence, when an African American or Hispanic American does poorly on a test, he or she must confront a disturbing possibility: that others will attribute the failure to racial inferiority. Similarly, females face stereotype threat when they venture into academic domains where stereotypes suggest that they are inferior to males, such as mathematics, engineering, and the physical sciences. That is, they worry about people blaming their failures on their gender. Steele maintains that stereotype threat can contribute to academic underachievement in at least two ways. First, it can undermine students' emotional investment in academic work. Many students may "disidentify" with school and write off academic pursuits as a source of self-worth. Their academic motivation declines and their performance suffers as a result. Second, standardized tests such as IQ tests may be especially anxiety arousing for members of stigmatized groups because the importance attributed to the tests makes their stereotype vulnerability particularly salient. This anxiety may impair students' test performance by temporarily disrupting their cognitive functioning. How Steele tested his theory is the topic of our Featured Study. Featured Study Racial Stereotypes and Test Performance In this article, Steele and Aronson report on a series of four studies that tested various aspects of Steele's theory about the ramifications of stereotype threat. We will examine their first study in some detail, and then discuss the remaining studies more briefly. The purpose of the first study was to test the hypothesis that raising the threat of stereotype vulnerability would have a negative impact on African American students' performance on a mental ability test. Method Participants. The participants were 114 black and white undergraduates attending Stanford University who were recruited through campus advertisements. As expected, given Stanford's highly selective admissions, both groups of students were well above average in academic ability, as evidenced by their mean scores on the verbal subtest of the SAT. The study compared black and white students with roughly equal ability and preparation (based on their SAT scores) to rule out cultural disadvantage as a factor. Procedure. The participants were asked to take a challenging 30-minute test of verbal ability composed of items from the verbal subtest of the Graduate Record Exam (GRE). In one condition, the issue of stereotype threat was not made salient. The test was presented to subjects as a way for researchers to analyze problem-solving strategies (rather than as a measure of ability). In another condition, the specter of stereotype threat was raised. The test was presented as an index of a person's general verbal ability. The principal dependent variable was each subject's performance on the verbal test. Results When the African American students' stereotype vulnerability was not made obvious, the performance of the black and white students did not differ, as you can see in Figure 9.18. However, when the same test was presented in a way that increased blacks' stereotype threat, the African American students scored significantly lower than their white counterparts (see Figure 9.18). Figure 9.18Stereotype Vulnerability and Test Performance Steele and Aronson (1995) compared the performance of African American and white students of equal ability on a 30-item verbal ability test constructed from difficult GRE questions. When the black students' stereotype vulnerability was not obvious, their performance did not differ from that of the white students; but when the specter of stereotype vulnerability was raised, the African American students performed significantly worse than the white students. Stereotype Vulnerability and Test Performanc SOURCE: Adapted from Steele, C. M., & Aronson, J. (1995). Stereotype threat and the intellectual test performance of African Americans. Journal of Personality and Social Psychology, 69, 797-811. Copyright © 1995 by the American Psychological Association. © Cengage Learning 2013 Discussion Based on their initial study, the authors inferred that stereotype threat appears to impair minority group members' test performance. They went on to replicate their finding in a second study of 40 black and white female students. In a third study, they demonstrated that their manipulations of stereotype threat were indeed activating thoughts about negative stereotypes, ability-related self-doubts, and performance apprehension in their African American participants. Their fourth study showed that stereotype vulnerability can be activated even when a test is not explicitly presented as an index of individual ability. Comment The concept of stereotype threat has the potential to clear up some of the confusion surrounding the controversial issue of racial disparities in IQ scores. It seems likely that socioeconomic disadvantage makes a substantial contribution to cultural differences in average IQ. However, various lines of evidence suggest that this factor cannot account for the culture gap by itself ( Neisser et al., 1996). Thus, Steele's groundbreaking research has provided scientists with an entirely new explanatory tool for understanding the vexing cultural disparities in average IQ. SOURCE: Steele, C. M., & Aronson, J. ( 1995). Stereotype threat and the intellectual test performance of African Americans. Journal of Personality and Social Psychology, 69, 797-811. The negative effects of stereotype threat have been replicated in numerous studies ( Cadinu et al., 2005; Croizet et al., 2004; Shapiro & Neuberg, 2007). A recent meta-analysis of thirty-nine stereotype threat experiments concluded that cognitive tests tend to underestimate the ability of negatively stereotyped students in real-world settings ( Walton & Spencer, 2009). Recent research has also provided new insight into how stereotype threat impairs test performance ( Schmader, 2010). The evidence suggests that reminders of negative stereotypes lead people to expend precious mental resources suppressing negative thoughts and monitoring themselves for signs of failure. These distractions hijack the very cognitive resource—working memory—that is critical to success on complex cognitive tests. This reduction in working memory capacity undermines test performance. Taken as a whole, the various alternative explanations for cultural and ethnic disparities in average IQ provide serious challenges to genetic explanations. Genetic explanations appear weak at best—and suspiciously racist at worst. Unfortunately, since the earliest days of IQ testing some people have used IQ tests to further elitist goals. The current controversy about ethnic differences in IQ is just another replay of a record that has been heard before. For instance, beginning in 1913, Henry Goddard tested a great many immigrants to the United States at Ellis Island in New York. He reported that the vast majority of Italian, Hungarian, and Jewish immigrants tested out as feeble-minded ( Kamin, 1974). As you can see, claims about ethnic deficits in intelligence are nothing new—only the victims have changed. Chapters

Note major milestones in the history of intelligence testing (355 - 357). Specifically, understand the general contributions of sir Francis Galton, Alfred Binet, Lewis Terman and David Wechsler to assessing intelligence. Also, understand the classic IQ formula developed by William Stern and used by Binet. Based on this formula, is it possible for two children to give the exact same answers on an IQ test and end up with significantly different scores?

Galton was the first person to study the concept of intelligence. Attempted to construct a test and failed. Strong genetic component. Binet- Developed the first accurate and valid intelligence test. Tested on school children. He used a formula that was developed by William Stern. Mental Age (how well they score on the test) over Chronological Age (child's biological age) equals Child's IQ. Lewis Terman- brought to the US and is now widely used in clinical circles. Wechsler - created IQ test specifically for adult population. WAIST. Top 3 professional tests.

Differentiate the traditional view of intelligence (factor analysis) from contemporary theories like those of Robert Sternberg and Howard Gardner (376 - 377). Specifically, differentiate Sternberg's three domains of intelligence and note Gardner's eight intelligences.

Traditional theory - 3 ultimate types of intelligence: verbal, mathematical, visiospatial. This is what most traditional scales have focused on. A new breed of theorists have come out; two majors are Robert Sternberg- triaric theory- several sets of major components shaped in a triangle. Practical, analytical and creative. We can't assume that if a person is high in analytical that they can apply it. Creative intelligence. Tells a story about 3 grad students and each high in one area. The one with practical got job first. Gardner- 8 major components- multi factor theory. One of them is logical/mathematical types/linguistics/spacial/ musical intelligence/ bodily intelligence ability to regulate muscle movements tiger woods micheal jordan/ naturalists - get systems of nature and how the world works in a physical sense/interpersonal - understanding how one person understands other people/ intrapersonal- understand own thoughts and emotions and keener insights/

Note basic questions about intelligence and their answers (358 - 362).

What types of questions? Does it tell about potential? Measure knowledge? Do they have validity and reliabilty? Do IQ scores really predict success in life?

Understand the complex interaction of genetic (twin & adoption studies) and environmental factors (environmental deprivation & enrichment) which influence intelligence (366 - 370).

genetic influences- Galton was right- intelligence is largely caused by genetics. If you were to measure a set of parents, what is observed is adopted child has closer IQ to birth parents. Twin studies- identical twins that are reared together are strikingly similar. Faternal twin- dizygotic - reared in the same home have IQs that are different than twins who are raised in different homes. Environmental factors play key role in where IQ will fall within a range. Can influence a score up or down. Enriched vs impoverished can influence range of IQ. IQ's have been increasing, the new norms are showing that we're getting smarter. An IQ of 100 today would have scored you 120-130 70 years ago.

What is meant by intellectual disability (formerly 'mental retardation') and how is it defined in IQ testing? (362 - 364). What is meant by giftedness and how is it defined in IQ testing? (364 - 365).

intellectual disability - Person has to have an IQ score 70-75 and evidence of poor functioning in life. What if the test had poor reliability? American Assoc of Mental Retardation added the poor functioning piece later because of test fallacies. Giftedness- 130 and above on quality test.

Arthur Jensen

sparked a heated war of words by arguing that racial differences in average IQ are largely the result of heredity. The cornerstone for Jensen's argument was his analysis suggesting that the heritability of intelligence is about 80%. Essentially, he asserted that intelligence is largely genetic in origin, and therefore, genetic factors are "strongly implicated" as the cause of ethnic differences in intelligence. Jensen's article triggered outrage and bitter criticism in many quarters, as well as a great deal of additional research on the determinants of intelligence.

Does culture play a role in intelligence? There are sharply differing answers to this question that often ignite hot tempered discussions, so be forewarned. What is the main thesis of Herrnstein & Murray's controversial book The Bell Curve? Is there evidence to support it? Is there evidence against their theory? (371 - 374).

A lot of disagreement on this issue. The Bell Curve, They argued that ethnic differences in average intelligence are substantial, not easily reduced by educational programs for the disadvantaged, and at least partly genetic in origin. The implicit message throughout The Bell Curve was that disadvantaged groups cannot avoid their fate because it's their genetic destiny. And as recently as 2010, based on an extensive review of statistical evidence, J. Phillipe Rushton and Arthur Jensen (2010) argued that genetic factors account for the bulk of the gap between races in average IQ. A vigorous debate continues as to whether cultural differences in intelligence are attributable mainly to the influence of heredity or of environment.

Validity

Even if a test is quite reliable, we still need to be concerned about its validity. Validity refers to the ability of a test to measure what it was designed to measure. If we develop a new test of assertiveness, we have to provide some evidence that it really measures assertiveness. Increasingly, the term validity is also used to refer to the accuracy or usefulness of the inferences or decisions based on a test ( Haladyna, 2006). This broader conception of validity highlights the fact that a specific test might be valid for one purpose, such as placing students in school, and invalid for another purpose, such as making employment decisions for a particular occupation. Validity can be estimated in several ways, depending on the nature and purpose of a test

Intelligence tests vs aptitude tests

Intelligence tests measure general mental ability. They're intended to assess intellectual potential rather than previous learning or accumulated knowledge. Aptitude tests are also designed to measure potential more than knowledge, but they break mental ability into separate components. Thus, aptitude tests assess specific types of mental abilities. For example, the Differential Aptitude Tests assess verbal reasoning, numerical ability, abstract reasoning, perceptual speed and accuracy, mechanical reasoning, space relations, spelling, and language usage. Like aptitude tests, achievement tests have a specific focus. However, they're supposed to measure previous learning instead of potential. Thus, achievement tests gauge a person's mastery and knowledge of various subjects (such as reading, English, or history).

Note key concepts in psychological testing focusing now on mental ability tests. You will be learning about personality tests later in the semester. Differentiate the terms intelligence test from aptitude test (350 - 353).

Psychological testing originated with efforts to measure general mental ability. Today, tests of mental abilities remain the most common kind of psychological test. This broad class of tests includes three principal subcategories: intelligence tests, aptitude tests, and achievement tests.

In order to trust and put faith in the results of a psychological test, the test must be reliable and valid. Differentiate the general concepts of test reliability and validity (351 - 353). You do not need to know the difference between the types of validity (content, criterion, construct) for the test but reading about them may help your understanding of test validity in general.

Reliability refers to the measurement consistency of a test (or of other kinds of measurement techniques). Psychological tests are not perfectly reliable. A test's reliability can be estimated in several ways ( Hempel, 2005). One widely used approach is to check test-retest reliability, which is estimated by comparing subjects' scores on two administrations of a test. If we wanted to check the test-retest reliability of a newly developed test of assertiveness, we would ask a group of subjects to take the test on two occasions, probably a few weeks apart (see Figure 9.1). The idea is that assertiveness is a fairly stable aspect of personality that won't change in a matter of a few weeks. Thus, any changes in participants' scores across the two tests would likely reflect inconsistency in measurement.

A correlation coefficient

is a numerical index of the degree of relationship between two variables. In estimating test-retest reliability, the two variables that must be correlated are the sets of scores from the two tests. If people get fairly similar scores on our two hypothetical assertiveness tests, this consistency yields a substantial positive correlation. The magnitude of the correlation gives us a precise indication of the test's consistency. The closer the correlation comes to +1.00, the more reliable the test is.

A psychological test

is a standardized measure of a sample of a person's behavior. Psychological tests are measurement instruments. They're used to measure the individual differences among people in their abilities, aptitudes, interests, and aspects of personality.