10-1 How do psychologists define intelligence, and what are the arguments for g?

In many studies, intelligence has been defined as whatever intelligence tests measure, which has tended to be school smarts. But intelligence is not a quality like height or weight, which has the same meaning to everyone worldwide. People assign the term intelligence to the qualities that enable success in their own time and culture (Sternberg & Kaufman, 1998). In Cameroon’s equatorial forest, intelligence may be understanding the medicinal qualities of local plants. In a North American high school, it may be mastering difficult concepts in tough courses. In both places, intelligence is the mental potential to learn from experience, solve problems, and use knowledge to adapt to new situations.

You probably know some people with talents in science, others who excel in the humanities, and still others gifted in athletics, art, music, or dance. You may also know a talented artist who is stumped by the simplest math problem, or a brilliant math student who struggles when discussing literature. Are all these people intelligent? Could you rate their intelligence on a single scale? Or would you need several different scales?

Charles Spearman (1863–1945) believed we have one general intelligence (often shortened to g) that is at the heart of all our intelligent behavior, from navigating the sea to excelling in school. He granted that people often have special, outstanding abilities. But he noted that those who score high in one area, such as verbal intelligence, typically score higher than average in other areas, such as spatial or reasoning ability. Spearman’s belief stemmed in part from his work with factor analysis, a statistical procedure that identifies clusters of related items.

This idea of a general mental capacity expressed by a single intelligence score was controversial in Spearman’s day, and so it remains. One of Spearman’s early opponents was L. L. Thurstone (1887–1955). Thurstone gave 56 different tests to people and mathematically identified seven clusters of primary mental abilities (word fluency, verbal comprehension, spatial ability, perceptual speed, numerical ability, inductive reasoning, and memory). Thurstone did not rank people on a single scale of general aptitude. But when other investigators studied these profiles, they detected a persistent tendency: Those who excelled in one of the seven clusters generally scored well on the others. So, the investigators concluded, there was still some evidence of a g factor.

We might, then, liken mental abilities to physical abilities: The ability to run fast is distinct from the eye-hand coordination required to throw a ball on target. Yet there remains some tendency for good things to come packaged together—for running speed and throwing accuracy to correlate. So, too, with intelligence. Several distinct abilities tend to cluster together and to correlate enough to define a general intelligence factor. Distinct brain networks enable distinct abilities, with g explained by their coordinated activity (Hampshire et al., 2012).

Satoshi Kanazawa (2004, 2010) argues that general intelligence evolved as a form of intelligence that helps people solve novel (unfamiliar) problems—how to stop a fire from spreading, how to find food during a drought, how to reunite with one’s tribe on the other side of a flooded river. More common problems—such as how to mate or how to read a stranger’s face or how to find your way back to camp—require a different sort of intelligence. Kanazawa asserts that general intelligence scores do correlate with the ability to solve various novel problems (like those found in academic and many vocational situations) but do not correlate much with individuals’ skills in evolutionarily familiar situations—such as marrying and parenting, forming close friendships, and navigating without maps.

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10-2 How do Gardner’s and Sternberg’s theories of multiple intelligences differ, and what criticisms have they faced?

Other psychologists, particularly since the mid-1980s, have sought to extend the definition of intelligence beyond the idea of academic smarts.

Howard Gardner has identified eight relatively independent intelligences, including the verbal and mathematical aptitudes assessed by standard tests (FIGURE 10.1). Thus, the computer programmer, the poet, the street-smart adolescent who becomes a crafty executive, and the basketball team’s play-making point guard exhibit different kinds of intelligence (Gardner, 1998). Gardner (1999) has also proposed a ninth possible intelligence—existential intelligence—the ability “to ponder large questions about life, death, existence.”

Gardner (1983, 2006; 2011; Davis et al., 2011) views these intelligence domains as multiple abilities that come in different packages. Brain damage, for example, may destroy one ability but leave others intact. And consider people with savant syndrome. Despite their island of brilliance, these people often score low on intelligence tests and may have limited or no language ability (Treffert & Wallace, 2002). Some can compute complicated calculations quickly and accurately, or identify the day of the week corresponding to any given historical date, or render incredible works of art or musical performance (Miller, 1999).

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About 4 in 5 people with savant syndrome are males, and many also have autism spectrum disorder (ASD), a developmental disorder. The late memory whiz Kim Peek (who did not have ASD) inspired the movie Rain Man. In 8 to 10 seconds, he could read and remember a page. During his lifetime, he memorized 9000 books, including Shakespeare’s works and the Bible. He could provide GPS-like travel directions within any major U.S. city, yet he could not button his clothes. And he had little capacity for abstract concepts. Asked by his father at a restaurant to lower his voice, he slid lower in his chair to lower his voice box. Asked for Lincoln’s Gettysburg Address, he responded, “227 North West Front Street. But he only stayed there one night—he gave the speech the next day” (Treffert & Christensen, 2005).

Robert Sternberg (1985, 2011) agrees with Gardner that there is more to success than traditional intelligence and that we have multiple intelligences. But his triarchic theory proposes three, not eight or nine, intelligences:

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With support from the U.S. College Board (which administers the widely used SAT Reasoning Test to U.S. college and university applicants), Sternberg (2006, 2007, 2010) and a team of collaborators have developed new measures of creativity (such as thinking up a caption for an untitled cartoon) and practical thinking (such as figuring out how to move a large bed up a winding staircase). These more comprehensive assessments improve prediction of American students’ first-year college grades, and they do so with reduced ethnic-group differences.

Gardner and Sternberg differ on specific points, but they agree on two important points: Multiple abilities can contribute to life success, and differing varieties of giftedness add spice to life and challenges for education. Under their influence, many teachers have been trained to appreciate such variety and to apply multiple intelligence theories in their classrooms.

Wouldn’t it be nice if the world were so just that a weakness in one area would be compensated by genius in another? Alas, say critics, the world is not just (Ferguson, 2009; Scarr, 1989). Research using factor analysis confirms that there is a general intelligence factor (Johnson et al., 2008): g matters. It predicts performance on various complex tasks and in various jobs (Gottfredson, 2002a,b, 2003a,b; see also FIGURE 10.2). Much as jumping ability is not a predictor of jumping performance when the bar is set a foot off the ground—but becomes a predictor when the bar is set higher—so extremely high cognitive ability scores predict exceptional attainments, such as doctoral degrees and publications (Kuncel & Hezlett, 2010).

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Even so, “success” is not a one-ingredient recipe. High intelligence may help you get into a profession (via the schools and training programs that take you there), but it won’t make you successful once there. Success is a combination of talent with grit: Those who become highly successful tend also to be conscientious, well-connected, and doggedly energetic. K. Anders Ericsson (2002, 2007; Ericsson et al., 2007) reports a 10-year rule: A common ingredient of expert performance in chess, dancing, sports, computer programming, music, and medicine is “about 10 years of intense, daily practice” (Ericsson, 2002, 2007; Simon & Chase, 1973). Becoming a professional musician requires a certain cognitive ability. But it also requires practice—about 11,000 hours on average, and a minimum of 3000 hours (Campitelli & Gobet, 2011). The recipe for success is a gift of nature plus a whole lot of nurture.

10-3 What are the four components of emotional intelligence?

Is being in tune with yourself and others also a sign of intelligence, distinct from academic intelligence? Some researchers say Yes. They define social intelligence as the know-how involved in social situations and managing yourself successfully (Cantor & Kihlstrom, 1987). People with high social intelligence can read social situations the way a skilled soccer player reads the defense or a meterologist reads the weather. The concept was first proposed in 1920 by psychologist Edward Thorndike, who noted, “The best mechanic in a factory may fail as a foreman for lack of social intelligence” (Goleman, 2006, p. 83).

One line of research has explored a specific aspect of social intelligence called emotional intelligence, consisting of four abilities (Mayer et al., 2002, 2011, 2012):

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Emotionally intelligent people are both socially aware and self-aware. Those who score high on managing emotions enjoy higher-quality interactions with friends (Lopes et al., 2004). They avoid being hijacked by overwhelming depression, anxiety, or anger. They can read others’ emotional cues and know what to say to soothe a grieving friend, encourage a workmate, and manage a conflict.

These emotional intelligence high scorers also perform modestly better on the job (O’Boyle et al., 2011). On and off the job, they can delay gratification in pursuit of long-range rewards, rather than being overtaken by immediate impulses. Simply said, they are emotionally smart. Thus, they often succeed in career, marriage, and parenting situations where academically smarter (but emotionally less intelligent) people might fail (Cherniss, 2010a,b; Ciarrochi et al., 2006).

Some scholars, however, are concerned that emotional intelligence stretches the intelligence concept too far (Visser et al., 2006). Howard Gardner (1999) includes interpersonal and intrapersonal intelligences as two of his eight forms of multiple intelligences. But let us also, he acknowledges, respect emotional sensitivity, creativity, and motivation as important but different. Stretch intelligence to include everything we prize and the word will lose its meaning.

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For a summary of these theories of intelligence, see TABLE 10.1.

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