week 8 Discussion EDU500
Chapter Fourteen Intelligence and Aging
One of the authors of this book vividly remembers her mother coming home after a trip into town, “just fit to be tied.” She was thoroughly disgusted with how she had been treated by a bank employee. The employee had insinuated that as a “little old lady” there was no way she could understand her different account options. As this mother reflected on her experience, still in an angry mood, she said, “I may be old and little, but I have not lost my mind and neither am I stupid.” This powerful myth—that adults lose their intellectual ability as they age—still prevails, even in the literature on intelligence and aging. However, over the past twenty-five years other scholars have put to rest that myth, backed up with a strong knowledge base that substantiates that for most adults intellectual functioning is alive and well throughout most of their lifetimes.
Intelligence is defined in a number of ways. From the perspective of the casual observer, intelligence is often equated with “being smart”—that is, being able to act intelligently when dealing with everyday life. But there is another definition of intelligence that many adults have carried with them since their elementary school days: intelligence is a specific measurement of their ability to learn. While not actually knowing their IQ scores, many adults have vague recollections of being labeled an “average,” “above- average,” or “below-average” student. Worse still are the memories of using IQ tests to be placed in a “slow” reading or math group, while watching a best friend be put in the “high” group. Although the concept of intelligence affects the lives of many adults, both through earlier and current experiences, what intrigues us is that educators of adults have given little attention to the study of intelligence in adulthood.
In this chapter, we first discuss the more traditional approaches to and theories of intelligence, focusing on those traditions that continue to have a very strong influence on intelligence in adulthood. We then argue that these traditional approaches continue to be foundational in how scholars both study and interpret the effect of aging on intelligence. Next, we explore the more recent challenges raised by scholars to these traditional approaches. In this section we examine key theoretical and empirical work that has promise for expanding how adult intelligence is conceptualized and in the future could have a significant effect on our basic understanding of aging and intelligence. The chapter concludes with a discussion of three ideas about intellectual functioning in adulthood that are particularly intriguing and useful for educators of adults.
Traditional Approaches to Intelligence
There are two reasons why it is important to understand what are often termed “the traditional approaches” to intelligence. The first is that the different lenses these researchers use “come not only from ideological biases affecting what is said, but also from what defines the concept of intelligence” ( Sternberg, Lautrey, & Lubart, 2003 , p. 3). And second, many of the ideas from these traditions still dominate the thinking and practice related to how intelligence is viewed, and hence, often unbeknownst to us, frame our practice as educators of adults.
Three areas within the more traditional approaches have been foundational in our thinking about adult intelligence: the biological approach, the individual differences approach, and the cognitive processes approach. Described more in depth in the next two subsections are the first two approaches. The third tradition, the cognitive processes approach, exemplified by the work of Piaget and Vygotsky, arises “from the construction of cognitive structures that materialize as a function of the interaction of the organism with the environment” ( Sternberg, Lautrey, & Lubart, 2003 , p. 3). While Piaget's (1952) work called our attention primarily to our biological maturation, Vygotsky (1978) was most interested in how the social environment around us influenced our intellectual development. Although both of these authors and their colleagues are often quoted in the literature on adulthood, very little empirical work with adults has been completed from this tradition (see Chapter Thirteen ).
The Biological Approach
Although the biological approach to intelligence is not often discussed by educators of adults, “nearly everyone believes that intelligence resides in the brain, and is virtually synonymous with brain power” ( Richardson, 1999 , p. 180). If we can only discover where in the human brain “intelligence resides” and how it fits into the way the brain operates, we will have the key to exactly what intelligence is. Tracing this rationale further, with this knowledge at some point the brain could be manipulated so that all humans could both become smarter and stay that way throughout their lives. Unfortunately, the knowledge we have gained about “the smart brain” has little practical application and is tentative at best. Rather, what scholars over the past two or three decades “have produced is an outpouring of interesting new facts and ideas. But it has to be admitted that psychologists and neuroscientists have not yet managed to weave these into a clear, or clearly agreed theory about how the brain produces, or is otherwise involved in human intelligence” ( Richardson, 1999 , p. 181). This search for the biological correlates of human intelligence is still strong, but it also needs to be more theoretically driven ( Haier, 2003 ; Vernon, Wickett, Bazana, & Stelmack, 2000 ).
Another avenue in the biology of intelligence couples it with the genetics of intelligence. This interest has been stimulated by those who assert that intelligence is an inheritable quality, and that people are born highly intelligent, “just so-so,” or way below the mean for functioning normally in society. There is no agreement in the current literature on the influence that genetic factors have on intelligence. Rather, there is a very wide spread of variations, with estimates ranging from 20 to 80 percent ( Bronfenbrenner, 2005 ). Even among researchers who argue that “genes play a sizeable part in influencing differences in mental ability between people” ( Deary, 2001 , p. 88), there is scant knowledge about what these genes are. However, with the ever-widening interdisciplinary approach to the study of human genetics, there are those who predict that we will discover, at some point in the future, the genetic composition of intelligence ( Grigorenko, 2000 ). If indeed these specific genetic markers are able to pinpoint intelligence, there will be a need to carefully consider both the practical and ethical issues that would be involved with such a discovery.
The Individual Differences Approach
The individual differences approach has and continues to have an enormous impact on the study of adult intelligence. In many ways this tradition has served the field well. First, scholars from this approach have provided a systematic means for studying individual differences. Second, “the theories embedded within this tradition have proved to have many and diverse applications. [In addition] they have provided a model for how theory and measurement can evolve in synchrony” ( Sternberg, Lautrey, & Lubart, 2003 , p. 2).
Grounded in the psychometric tradition, viewing the concept of intelligence from this approach assumes that intelligence is a measurable construct. Although testing for individual differences in intelligence is most often done with children and adolescents, this form of testing still has a significant influence on how adults continue to be sorted, left out, or included in educational, work, and even living situations. Using the psychometric approach there are two primary ways that individual differences in intelligence are conceptualized: general intelligence (or the “g” factor) and multiple factors ( Embretson & Schmidt McCollam, 2000 ).
Jensen (2002) observes that in “the state of the art in the field of psychology, a clear conclusion is warranted: That is, a century of research on intelligence suggests there are abilities and processes in intellectual functioning that are truly general, very strong in their affect and always present” (p. 5). Numerous scholars agree with Jensen's view that the g factor is alive, well, and thriving, and tests that measure this factor are used in numerous settings with adults ( Deary, 2001 ; Sternberg & Grigorenko, 2002 ). The central tenant of theory building and research related to the g factor is that a person's performance on one or more scales can be explained as a single underlying ability ( Sternberg & Grigorenko, 2002 ). Therefore, scores from diverse tests or subscales can be combined to form a general intelligence quotient, commonly known as the g factor.
Spearman (1904, 1927) and Binet (1916) are representative of the early researchers who sought to understand the nature of intelligence as a single well-defined construct. The first massive use of intelligence testing with adults using the g factor as the norm was with men entering the army in World War I. As large numbers of recruits needed to be tested quickly, two IQ tests were developed ( Kaufman, 2000 ). The practical consequences of the development of these tests were many. For example, “IQ tests [using the g factor] were found to be useful for adults, not just children; were perceived to be valuable for high functioning people, not just the lower extreme,” and the data analysis from huge samples (almost two million) led to intense controversies, from “cries of racism and inferiority, to debates about the value of IQ tests and their social implications” ( Kaufman, 2000 , p. 446). Examples of often-quoted current scholars who study the g factor are Carroll (1993) , Jenson (2002), Humphreys and Stark (2002) , and Petrill (2002, 2003).
The more prevalent use of IQ tests with adults to measure individual differences is with those that include multiple factors of intelligence, such as spatial ability, perceptual speed, numerical ability, verbal relations, words, memory, and induction. Of the earlier theorists who advocated this point of view, Horn and Cattell (1966, 1967) have had the widest influence on conceptualizing intelligence as multiple factors. In addition, their work has been foundational to the study of intelligence in adulthood. The Horn-Cattell theory viewed intelligence as consisting of two broad areas: fluid intelligence (Gf) and crystallized intelligence (Gc). The fluid arena captured those tasks that “demanded new problem solving with minimal dependency on school learning or acculturation” ( Kaufman, 2000 , p. 460), and was therefore viewed as more innate and dependent on a neurophysiological base. In contrast, the crystallized domain was viewed as education dependant and more associated with accumulated information.
Horn (1985, 1989) expanded this Gf-Gc theory by shifting his focus to a group of eight to ten abilities, with the measure of each being “purer” and with no overlap between the factors. “From current Horn theory, tasks are only categorized as Gf if they emphasize reasoning ability and as Gc if they stress comprehension and knowledge base” ( Kaufman, 2000 , p. 460). In addition, Horn (1985, p. 289) changed one of the basic assumptions of this theory, which is that “there are good reasons to believe that Gf is learned as much as Gc, and that Gc is inherited as much as Gf.” Instead, he believes that both types of intelligence can be nurtured, at least until very old age. This assertion has led researchers to study whether fluid intelligence, which was thought to be primarily innate, can be either restored (if loss has been shown) or strengthened as people age ( Lohman & Scheurman, 1992 ; Schaie & Willis, 1986 ; Willis & Schaie, 1994 ). Schaie (1996b) has provided a clear and cogent summary of this work.
Psychometric tests using the multiple factors methods are most often used with adults in assessing people in the workplace for job placement, in clinical settings for appropriate treatment plans, and in the military, where a certain score is required for entry. In addition, these types of intelligence tests have been used in research to determine how intellectual abilities change as people age. The three tests that measure multiple factors of intelligence most often used in both research and practice with adults are the Kaufman Adolescent and Adult Intelligence Test (KAIT; Kaufman & Kaufman, 1993 ), the Wechsler Adult Intelligence Scale, which is now in its third edition (the WAIS-III), and the Primary Mental Abilities (PMA) test, the most recent version being the Schaie-Thurston Adult Mental Abilities Test (STAMAT; Schaie, 1979 , 1985 ). Each of these tests appears to primarily assess mental abilities, such as verbal and reasoning ability, related more to formal schooling than everyday intelligence ( Deary, 2001 ; Sternberg et al., 2000 ). In a challenge to this idea, Schaie and others ( Schaie, 1996b ; Willis & Schaie, 1986 ) found that, at least in later adulthood, certain primary mental abilities do predict competent behavior in specific situations—for example, “competence in active situations was predicted by spatial ability and inductive reasoning, and competence in passive situations was predicted by verbal abilities” ( Schaie & Willis, 1986 , p. 290). Therefore, to these researchers, the findings suggest “a strong relationship between the ‘building blocks’ of intelligence and abilities on real life tasks” (p. 290).
Two of these intelligence tests, the Kaufman Adolescent and Adult Intelligence Test ( Kaufman & Kaufman, 1993 ) and the Wechsler Adult Intelligence Scale-Third Edition ( Wechsler, 1997 ), are examples of measures that have been primarily constructed using the work of Horn and Cattell. Within the KAIT framework ( Kaufman & Kaufman, 1993 ), fluid intelligence “measures a person's adaptability and flexibility when faced with new problems.” Crystallized intelligence evaluates “the acquisition of facts and problem-solving ability using stimuli that are dependent on formal schooling, cultural experiences, and verbal conceptual development” ( Kaufman & Kaufman, 1993 , p. 7).
The WAIS-III is designed for adults ages sixteen to eighty-nine. The WAIS-III, like its predecessors (the WAIS-R and the WAIS), consists of six regular verbal subtests and five mandatory performance tasks. Several of the WAIS-III subtests are often grouped together for measuring Horn's expanded concepts of fluid and crystallized intelligence. Like the KAIT, the WAIS-III also may present problems in the testing of the elderly, and more specifically those seventy-five and above. However, “The WAIS-III is likely to follow in the footsteps of the WAIS-R, which has proven itself as a leader in the field of adult assessment” ( Kaufman, 2000 , p. 459).
The third test of adult intelligence, the Primary Mental Abilities test, is often associated with the work of Schaie and colleagues on intelligence and aging (Schaie, 1979 , 1985 , 1996a). The underlying assumption of the PMA test, originally developed by Thurstone and Thurstone (1941) , is that intelligence is actually several distinct abilities. Purported to measure five relatively independent factors, the PMA test battery consists of five subtests: (1) verbal meaning, which is the ability to understand ideas expressed in words; (2) space, describing the ability to think about an object in two or three dimensions; (3) reasoning, involving the ability to solve logical problems; (4) number, the ability to handle arithmetic problems; and (5) word fluency, concerning the speed and ease with which words are used.
As we demonstrate in the next section, the individual differences approaches to intellectual development continues to dominate how scholars have argued whether adults lose or perhaps even gain in intellectual abilities as we age. Central to this discussion of linking age and intelligence is whether adults, and especially older adults, will be as intellectually capable in their sixties and seventies as they were in their twenties and thirties.
Age and Intellectual Abilities
“The study of the depth and breadth of interest in intellectual changes during adulthood has increased dramatically in recent decades” ( Dixon, 2003 , p. 152). The fundamental question that researchers have struggled with over the years is: Does intelligence decline with age? In their pioneering work in this arena, Thorndike, Bregman, Tilton, and Woodyard (1928) were among the first scholars who challenged the fundamental notion that learning ability peaks very early in life. Using primarily laboratory or schoolroom tasks, Thorndike measured the speed of the performance of people from ages fourteen to fifty on a variety of tasks, from memorizing poetry to acquiring an artificial language ( Kidd, 1973 ). Thorndike et al. (1928, pp. 178–179) concluded from their many studies that “in general, teachers of adults of age twenty-five to forty-five should expect them to learn at nearly the same rate and in nearly the same manner as they would have learned the same thing at twenty.” In reflecting on Thorndike's work, Kidd (1973) noted two major contributions. The first was to raise the age of onset of the downhill slide of a person's ability to learn from twenty years of age to forty-five; second, and even more important, Thorndike “helped to stimulate colleagues to reject traditional views and formulas” (p. 79) about learning in adulthood.
Naturally, this question related to whether intelligence declines with age is of no small interest to current scholars and also to many adults who wonder if in fact they will become less “with it” as they age. Responses to this question are mixed and often have been controversial. They range from the contention that intelligence definitely enters a process of irreversible decline as we age (though that age does differ from scholar to scholar) to those who argue that intelligence is relatively stable through the adult years, with substantial changes occurring very late in life. Underlying these highly diverse responses are issues of universality, directionality, and reversibility in intellectual functions over the life span. Do changes in intelligence “occur generally or differently in normal aging adults?” ( Dixon, 2003 , p. 153). Are these changes progressive or regressive in nature? And what is the potential for adults to alter or compensate for any of these changes? One way to respond to these underlying questions is through understanding how scholars who study intelligence and aging define the concept of intelligence, delineate the parameters of aging, and select the designs and measures they use in this research.
Concept of Intelligence
In looking at the concept of intelligence we can see how the different ways this construct is defined provide different responses to the questions of directionality and reversibility of intelligence. As noted earlier, although there is no universal agreement as to what constitutes intelligence, the study of intelligence and aging is deeply rooted in the individual differences approach. Because this approach assumes that intelligence is a measurable construct, when we speak of intelligence and aging our observations come primarily from a comparison of test scores. These tests are designed to investigate a specific theory or theories and factors thought to be the major components that constitute intelligence. For example, the PMA test defines intelligence as five relatively distinct measures of psychological competence, versus a single general intelligence factor.
From Schaie's perspective, when intelligence is defined as a unitary property, the research tends to confirm that intelligence does indeed decline with age, although again the point of departure for that decline often varies ( Schaie & Willis, 1986 ). Yet when intelligence is viewed as consisting of multiple factors, the response tends to be that some of our abilities decline, while others remain stable or even increase ( Baltes, 1993 ; Berg, 2000 ; Dixon, 2003 ; Schaie, 1996b ).
Other authors, including Baltes and Schaie, have added important properties to their definitions of intelligence. Two of those properties—plasticity and compensation processes—are key in addressing the issue of whether adults can in some way change the course of their intellectual development. Again, these added properties need to be placed in the context of the data sources used, which are primarily empirical studies based on traditional intelligence tests.
Plasticity refers to the ability for people to change and yet also maintain a certain durability as they age. Research on “the plasticity of intelligence has focused on the modifiability of intelligence through intervention” ( Berg, 2000 , p. 122). Dixon (2003) asserts in his review of literature related to intervention research that “it is possible to train normal older adults to perform better on challenging cognitive tasks” (p. 156). He contends that researchers have demonstrated that older adults can improve their performance on intelligence tests through self-directed practice and formal training on higher-level tasks. In addition, those adults who have received this formal training can also perform more effectively on some cognitive tasks in everyday life. Based on these studies, Dixon goes on to observe: “Theoretically this implies that some degree of normally observed decline in intellectual aging may be the result of disuse and that potential for improvement may be present in older adults” (p. 157).
Compensation is among the most promising expansions to the nature of intelligence. Embedded in the individual differences and in the information processing approaches to intelligence, compensation refers to ways that adults adapt to losses in cognitive processes that may affect their intelligence as they age, and can take many forms. For example, adults can invest more time and effort in a task, learn new ways to perform the same task, and adjust their goals and criteria for success to accommodate any losses or deficits. For example, one of the authors has a ninety-one-year-old friend who has chosen to live in her own apartment rather than in another, alternative living arrangement available to her in the complex where she lives. Due to severe arthritis this woman can no longer use her hands to complete many household tasks, so, instead, she has learned to do these tasks, like making a bed, with her feet. She has also chosen to play bridge every day versus only twice a week so she does not lose her competitive edge, and she makes sure she takes a cocktail before dinner in a common lounge with other residents to maintain her contact with those who live in the same area. “Compensation may occur automatically at the level of the brain or may be trained deliberately in impaired individuals” ( Dixon, 2003 , p. 157).
Parameters of Aging
The question of directionality—that is, whether we gain or lose our intellectual abilities as we age—is also addressed when we discuss how scholars define the parameters of aging. Whether or not one believes intelligence declines with age depends on the ages of the adults included in the study. Are we talking about adults in early, middle, or later adulthood? In reviewing data on early and middle adulthood, our response would be that intelligence does not decline with age. In fact, some intellectual functions, no matter what testing procedures are employed, seem to increase over the course of the years. Our response to whether intelligence declines in later adulthood is not as clear-cut ( Baltes, 1993 ; Schaie, 1996a , 2005 ). Most agree that some decline in functioning occurs between age sixty and the early seventies, but the precise nature of that decline, and more important, its practical effect on learning ability are still in question.
In line with this observation, although there have been numerous studies of older adults ( Schaie & Hofer, 2001 ), only a few have addressed the intellectual abilities of healthy adults after age 70. In one longitudinal comparison of subjects ranging in age from 73 to 99, researchers found that although many of the subjects showed some decline in abilities, more than half displayed no such changes, even at the older ages ( Field, Schaie, & Leino, 1988 ). In a more recent study of eighteen people between the ages of 100 and 106, these “centenarians reported rich late-life learning experiences, the majority of [which] occurred through social interactions” ( Fenimore, 1997 , p. 57).
Research Designs and Measures
The questions that surround the issues of directionality and universality are important issues raised by those who discuss how research designs and measures affect our thinking about intelligence and aging. The research designs employed in investigations of changes in intelligence over the life span also are a major point of discussion in the literature. Results from the two most often used designs, cross-sectional and longitudinal, usually provide very different findings. Data from cross-sectional studies, which compare onetime test scores of different age groups (for example, twenty-year-olds and sixty-year-olds) predominately show that as we age our intelligence declines (Schaie, 1994 , 1996a ; Schaie & Hofer, 2001 ). Findings from longitudinal studies, however, usually support a very different conclusion. Based primarily on readministration of intelligence tests over time and to the same group of people, various longitudinal investigations demonstrate that intellectual abilities of groups of older people are remarkably stable over time ( Rabbitt, Donlan, Brent, McInnes, & Abson, 1993 ; Schaie, 1996b , 2005 ).
Cross-sectional designs only allow inferences about differences of intellectual abilities for specified age groups, such as adults in their twenties and those in their sixties. In addition, even in the claims that are made based on these data there are numerous limitations inherent to this design. For example, cohort differences, such as level of formal education and health status, may cloud results. In addition, “as the 20th century progressed, the whole population's scores on some well-known mental tests were improving when compared with same-age people generations earlier” ( Deary, 2001 , p. 104), which further confounds these cross- sectional comparisons between the young and the old.
In contrast, longitudinal studies permit scholars to draw a broader picture of intellectual development through the adult life span. By providing information on both cohort-age-specific and individual differences in adults as they age, they allow researchers to explore more complex issues and questions. For example, researchers are able to address whether there are individual differences or similarities in intellectual abilities as adults age. They also are able to investigate how other factors, such as health, social interactions, and psychological attributes, may contribute to the continued stability or decline in intellectual functioning. As with cross-sectional designs, longitudinal studies also have built-in limitations, such as selective attrition and dropout, and retaking the same or similar performance tests over time. In addition, “effects thought to be age-dependent must be carefully disaggregated from those due to historical limited events and environmental impacts” ( Schaie & Hofer, 2001 , p. 56).
In response to the limitations and problems associated with both cross-sectional and longitudinal designs, researchers have adopted alternative designs to control for some of the biases inherent when only a cross-sectional or longitudinal design is used. Schaie and his associates, as part of the Seattle Longitudinal Study, provide the best example of the work using one of these alternative designs (Schaie, 1994 , 1996b , 2005; Schaie, Willis, & O'Hanlon, 1994 ). The primary variables for this study were the five factors that represent the primary mental abilities of adults. The data for the study were collected from more than five thousand subjects over a thirty-five-year period in six testing cycles. With six cross- sectional studies, in addition to longitudinal data, the researchers were able to do a number of different forms of analysis. In essence, the cross-sectional data showed a typical pattern of intellectual decline, while the longitudinal data suggested little if any decline of any practical consequence until after the mid- to late sixties. Even “this decrement is modest until the 80s are reached, and for most individuals it is not a linear phenomenon but occurs in stair-step fashion” ( Schaie, 1994 , p. 308). Schaie and others attributed the differences in findings between the two research designs to cohort variation—differences between the generations versus differences in the ages of subjects. These cohort variations are, in turn, attributed to higher educational levels of succeeding generations and overall better nutrition and health care.
In addition to providing answers to the question of directionality, the findings from the Seattle Longitudinal Study and studies of like nature ( Schaie & Hofer, 2001 ) also offer helpful insights into whether these changes in intelligence as we age are universal or occur differently in normal aging, and are progressive or regressive in nature. Schaie and his associates, for example, “emphasized that considerable individual differences exist in both degrees of intellectual decline and the age of onset” ( Dixon, 2003 , p. 153). Seven variables were identified that reduce the risk of cognitive decline in old age: absence of cardiovascular and other chronic diseases, living in favorable environmental circumstances, substantial involvement in activities, maintenance of high levels of perceptual processing speed into old age, being married to a spouse of high cognitive status, and rating one's self as satisfied with one's life. We would conjecture that health, economic means, and feeling good about life are central to continued intellectual vitality and that the other variables might just be a plus, or perhaps go with having economic means.
In exploring the other side of the question—which factors predict earlier-than-average decline—four were identified: significant decrease in being flexible in one's approach to life, low educational attainment, being male, and a low satisfaction with life success ( Schaie, 1994 ). Except for gender, of course, some of these variables may be amenable to change using the typical interventions recommended to offset and even possibly restore decreases in intellectual capabilities ( Dixon, 2003 ). They may also suggest different kinds of interventions, like personal counseling and enrolling in formal educational programs.
Most research on the effects of intelligence and aging has been conducted using either the Weschler scales (WAIS-III or the earlier WAIS-R) or a form of the PMA test. One big question, still strongly debated today, is whether either of these two measures, and others of this nature, capture more than the academic or “mental abilities” versus intelligence in everyday life. Sternberg and associates ( Sternberg, 2000b ; Sternberg et al., 2000 ) would respond with a resounding no, although Sternberg does see the value of tests of this nature used in concert with measures of practical intelligence. Scholars like Gardner (1999b, 2003) and Tennant and Pogson (1995) would argue that these tests do not capture the more complex nature of intelligence.
A second question raised on both of these tests, and others like them, has been their inclusion of timed items. All of the PMA subtests, and about half of the subtests in the WAIS-III are timed. Are timed tests, particularly ones involving perceptual motor functions, valid measures of adult intelligence, especially for older adults? Some scholars strongly argue that speeded tests should be eliminated in assessing adult intelligence, whereas others make compelling augments that timed items should be included, because mental speed is a critical component of intellectual functioning ( Deary, 2001 ).
In summary, our answer to the fundamental question “Does intelligence decline with age?” leads us back to our discussions of the concept of intelligence, age parameters, and research designs and measures. With these factors in mind, our response to this question is that intelligence may decline, remain relatively stable until late adulthood, or even be enhanced as we age. One school of thought contends that intellectual functioning is a process of irreversible decline in the adult years, although the hypothesized onset and the extent of that decline are still unknown. The majority of those who argue this position are relying on data from cross-sectional studies or are firmly entrenched in the belief that intelligence is an inheritable trait.
Others say that intelligence is relatively stable through the adult years, with substantial intellectual changes occurring only very late in life, and then primarily “in abilities that were less central to the individual's life experience and thus perhaps less practiced” ( Schaie, 1996b , p. 2). In essence, we have enough brain capacity to do almost anything we choose, until serious illness or when we are in highly challenging, complex, or stressful situations. Still others argue that intelligence declines in some respects, remains stable in others, and may even increase in some functions, depending on a person's educational level, life experiences, overall health, and outlook on life ( Dixon, 2003 ; Kaufman, Kaufman, Chen, & Kaufman, 1996 ; Raykov, 1995 ). Those who assert the latter two points of view primarily point to longitudinal or mixed-design studies on aging and intelligence and define intelligence as multifaceted.
As will be discussed in the next section, it is hoped that more recent and future research on different approaches to adult intelligence will provide further insight into whether the individual differences approach can continue to be used as the best predictor of how intelligence changes with age. Or, might these alternative ways of thinking about adult intelligence possibly provide a clearer and perhaps even a more complex picture of the effects of aging on intellectual functioning?
Challenges to the More Traditional Concepts of Intelligence
Major challenges about the nature of intelligence have been made by a number of scholars in the past twenty years. These critiques have come from numerous sources, but they center on three main issues. The first is the major focus on the individual, and more specifically, differences between individuals as measured by psychometric tests. Second, there is, in the words of Sternberg, Lautrey, and Lubart (2003), “a fighting for the ‘truth’ … with the underlying notion … that only one model or theory could be correct” (p. 11). Third, the majority of these traditional ways of thinking about intelligence in adulthood do not take into account “real-world” or “everyday” intelligence. Theorists who advocate that the basic nature of intelligence has to be reframed most often view intelligence as a combination of biological, psychological, social, cultural, life experiences, and environmental factors. Rather than focusing on just one or two of these frames, scholars from this tradition argue that intelligence consists of multiple domains and most often is conceived as an interaction among three or more of them.
Tennant and Pogson (1995) have provided a thoughtful treatise on why these challenges to intelligence have been overlooked for so long, especially by scholars representing Western culture. They assert that “historically, Western culture has taken a lower view of manual work than of cognitive activity” (p. 37), which has led to “the exaltation of the theoretical or contemplative over the practical” (p. 39). More specifically, they cite the attributes of verbal, abstract, and complex thinking as far more valued than either those of concrete and sensual thought or the active use of knowledge.
In discussing these alternative ways of defining the nature of intelligence, we focus on Gardner's theory of multiple intelligences (the MI theory); practical intelligence, illustrated by the work of Sternberg and his colleagues; and emotional intelligence. We also explore the way culture affects how intelligence is viewed. We chose these specific theories and studies to illustrate these alternative stances because educators of adults have gravitated to these viewpoints of intelligence, considering them more applicable to adult learners.
Gardner's Theory of Multiple Intelligences
Gardner is representative of theorists who broke away from the psychometric tradition of intelligence during the early 1980s. From Gardner's perspective, the concept of intelligence has been too narrowly limited to the realm of logical and linguistic abilities, primarily by the way intelligence has been measured. He argues that “there is persuasive evidence for the existence of several relatively autonomous human intellectual competencies that can be fashioned and combined in a multiplicity of adaptive ways by individuals and cultures” ( Gardner, 1993 , pp. 8–9). From a number of unrelated sources, such as studies of prodigies, brain-damaged patients, and normal children and adults, Gardner originally identified seven different forms of intelligence, with an eighth added in the mid-1990s. The original seven forms of intelligence include “not only the standard academic ones of linguistic, logical-mathematical, and spacial (the visual skills exhibited by a painters or architect) but also musical, “bodily-kinesthetic,” and two “personal” intelligences involving a fine-tuned understanding of oneself and others” (Levine, 1987, p. 54). Gardner's eighth form of intelligence, naturalist intelligence, takes us to a different realm. The intelligence of naturalists is in recognizing and categorizing natural objects and patterns in their environment. This type of intelligence is exemplified in the work of formal scientists, such as biologists and environmentalists, but also people who are highly skilled in applying “folk taxonomies,” such as natural healers, and other abilities, like farming and hunting (see Gardner, 1983, 1993, 1999b, for a complete description of his eight intelligences). Gardner has also discussed another possible form of intelligence—“existential intelligence.” Adults who exhibit existential intelligence capture and ponder “the fundamental questions of existence”: spiritual leaders and philosophical thinkers are among such people ( Gardner, 1999a , p. 22). Gardner has not yet added this form of intelligence to his current eight due to its perplexing nature and its distance from the other intelligences. “At the most, I am willing, Fellini-style, to joke about ‘8 and 1/2 intelligences’” ( Gardner, 1999b , p. 66).
In introducing the theory of multiple intelligences, Gardner (1993) emphasized that the idea has a rich history, recognized even in early Greek times. He makes only two strong claims about the theory. The first is that all humans possess all of these intelligences: indeed, they can collectively be considered a definition of Homo sapiens, cognitively speaking. The second claim is that just as we all look different and have unique personalities and differences, we also have different patterns of intelligence ( Gardner, 1999a ). Therefore, in Gardner's framework, our tendency to label people as being generally bright, average, or dull just does not fit. Rather, a person may exhibit high intelligence in one or more areas, such as music and math, and yet demonstrate only average intelligence in other respects. In other words, you can be very talented in specific areas and have some or little capacity in others. In addition, Gardner views MI theory as presenting a critique of the predominant model of “psychometrics-as-usual” in measuring intelligence. Therefore, although scholars have made some attempts to develop and use tests that measure multiple intelligences (for example, Rosnow, Skleder, Jaeger, & Rind, 1994 ; Shearer & Jones, 1994 ), Gardner (1995) himself argues that any assessments of multiple intelligences must be “‘intelligent fair’; that is, in ways that examine the intelligence directly rather than through the lens of linguistic or logical intelligence (as ordinary pencil and paper tests do)” (p. 202).
When Gardner proposed his MI theory, he was interested in both promoting theory building on the nature of intelligence with his fellow psychologists and having scholars examine the educational implications of his theory. His work has stirred a great deal of theoretical debate among scholars, but what Gardner was unprepared for was the almost overwhelming positive response among educators of preschool and elementary-school-age children, which then spread even to the secondary and college levels (Gardner, 1993 , 1995 , 1999b; Rosnow, Skleder, Jaeger, & Rind, 1994 ; Shearer & Jones, 1994 ). For example, MI theory was almost immediately put into practice and whole curricula for school-age children have been developed using the theory. The conclusion that Gardner (1999a) himself has reached “is that the MI theory is best thought of as a tool rather than an educational goal” (p. 21).
The use of MI theory has been much more limited in applications to situations of adult life. Gardner (1999b) noted that, more recently, “a growing number of businesses have been attracted to the themes of MI: as input to the human resources department, as a means for creating or marketing products, or as training for a more effective learning environment” (p. 202). But Gardner also cautions that, although there are some applications to individuals and perhaps even to organizations, in the work world “what is important is whether people can do their jobs, not what particular intelligences they happen to be applying” (p. 198).
One example of a highly systematic use of the MI theory has been with programs of adult literacy. The Adult Multiple Intelligences (AMI) study was a project under the auspices of the National Center for the Study of Adult Learning and Literacy (NCSALL) at Harvard University ( Viens & Kallenbach, 2004 ). In Phase 1 of the study, ten teachers of ESOL, ABE, GED, or diploma preparation programs from five New England states “took on the challenge to help their students identify and use diverse pathways to learning English, basic skills, and content utilizing the MI theory” (p. ix). One result of their work was a draft sourcebook for adult literacy teachers who wanted to learn about and use MI theory in their classrooms. In Phase 2, twelve additional adult literacy teachers from four diverse locations around the United States piloted a first draft of this sourcebook. One of the most important outcomes of that pilot study is Multiple Intelligences and Adult Literacy: A Sourcebook for Practitioners ( Viens & Kallenbach, 2004 ). This sourcebook provides a very clear description of MI theory and its promises and challenges; useful resources on how to develop various learning strategies that can tap into students’ strengths; and “stories” from students and teachers, some of whom found using the MI theory very helpful as part of the learning process and others who found it rather cumbersome to their central tasks.
We do see significant value in integrating Gardner's MI theory into our research and practice of learning in adulthood. But we are also well aware that there is a major need for more systematic validation studies of the basic dimensions of the MI theory, and more specifically, whether this theory is applicable to adults, and if so, for whom, where, and how. We recommend paying heed to Gardner's (1995) position that there is no “single educational approach based on the MI theory, [and] that educators are in the best position to determine the uses to which MI theory can and should be used” (p. 206).
Practical Intelligence
Sternberg and his associates have been the most active and prolific scholars responding to the challenge to reframe the concept of intelligence. Like Gardner, they too have broken from the tradition of framing intelligence as primarily a measure of what they have come to call “academic intelligence” to one that includes problem solving for everyday life. More specifically, they argue that “the problems faced in everyday life often have little relationship to the knowledge and skills acquired through formal education or the abilities used in classroom activities” ( Sternberg et al., 2000 , p. 32). Consider, for example, an adult who returns to school to earn his RN license. He does extremely well in his classes and clinical experiences. Yet he finds through his first job as a nurse in an acute care hospital that his overall performance is less than adequate. He has great difficultly keeping up with all the demands of the doctors and the needs of his patients, and even worse, he panics in emergency situations.
The theoretical framework used most often by Sternberg and his associates, and also by other scholars who study practical intelligence, is the triarchic theory of intelligence. According to Sternberg (1985, 1986a, 1988), the triarchic theory is composed of three subtheories: a componential subtheory, describing the internal analytical mental mechanisms and processes involved in intelligence; an experiential subtheory, focusing on how a person's experience combined with insight and creativity affects how she thinks; and a contextual subtheory, emphasizing the role of the external environment in determining what constitutes intelligent behavior in a situation. The first part of the subtheory, the mental mechanisms of intelligence, is posited as universal: “Although individuals may differ in what mental mechanisms they apply to a given task or situation, the potential set of mental mechanisms under-lying intelligence is claimed to be the same across all individuals, social classes, and cultural groups” ( Sternberg, 1986a , pp. 23–24). The other two parts of Sternberg's theory, which emphasize the experience of the learner and the real-world context, are seen as having both universal and relativistic components. The universal aspect has to do with areas being studied within each of these subparts of the theory (such as the processes of automation, environmental adaptation, and shaping). These processes are seen as important no matter what the cultural milieu or the person's experience with the tasks or situations chosen to measure these aspects. The relativistic nature of these parts of the theory comes from the recognition that what constitutes intelligent behavior is not the same for all groups of people. As Sternberg puts it, “Parts of the theory are culturally universal, and parts are culturally relative” (1986a, p. 24).
Sternberg and colleagues are still in the process of validating an empirical test of the triarchic theory of intelligence. A revised version of Sternberg's Triarchic Abilities Test (STAT) has been developed, focusing on additions to the measurements used for creative and practical intelligence. In addition to the presentation of problems through verbal, quantitative, and figural representations, they have added other types of items. For example, they are now asking participants “to write and tell stories or captions for cartoons, and [to solve] everyday problems presented in films, and by an office-based situational judgment inventory” ( Sternberg, 2003a , p. 61). Studies of this revised edition are still in progress, and it is our understanding that the STAT is still not being used beyond the experimental phase of test validation ( Brody, 2003 ; Sternberg, 2003a ; Sternberg, Castejón, Prieto, Hautamäki, & Grigorenko, 2001 ). In addition, we could locate only one study in which adults were the audience for this continuing evaluation of the STAT ( Sternberg, 2003a ).
Sternberg (1997, 2003b) has expanded on the triarchic theory further through his research on “successful intelligence.” His view of successful intelligence is grounded in the same basic components as those in his triarchic theory, although these underlying components are labeled a bit differently, and also, the basic meaning of those components has changed somewhat. “To be successfully intelligent is to think well in three ways: analytically, creatively, and practically” ( Sternberg, 1997 , pp. 126–128). Sternberg highlights that it is not enough just to have these three abilities; rather, people are successfully intelligent when they are able to choose how and when to use these abilities effectively. For example, students in graduate programs often develop research studies that meet the test of being highly analytical in nature. Nonetheless, the problems they choose to study may not be important to their fields (lack creative intelligence) or have little practical significance (something valued in educational research).
Sternberg and associates (Sternberg, 1996b , 1997 ; Sternberg et al., 2000 ; Sternberg & Horvarth, 1999; Wagner, 2000 ) have further delineated one of the three components that compose the theories of triarchic and successful intelligence by exploring in more depth the concept of contextual or practical intelligence. These scholars argue that tacit knowledge is a central component of practical intelligence. Tacit knowledge is defined as “knowledge that reflects the practical ability to learn from experience and to apply that knowledge in the pursuit of personally valued goals” ( Sternberg et al., 2000 , p. 104). In their opinion, it is this tacit knowledge that allows adults to successfully adapt to, select, or shape real-world environments.
Sternberg et al. (2000) present a clear and cogent discussion of how tacit knowledge has been measured with adults, ranging from critical incidents and simulations to the initial development and testing of tacit knowledge inventories. The research on building tacit knowledge inventories was conducted with a variety of adult populations (for example, academic psychologists, business managers, people who enroll in general leadership training programs, and military leaders). Among their findings are “that individuals who exhibit the ability to acquire and use tacit knowledge are more effective in their respective performance domains” ( Sternberg et al., 2000 , p. 223). In addition, “although the acquisition of tacit knowledge appears to be influenced, to some extent, by ‘g’ and by the amount of experience, tacit knowledge inventories are not simply new measures of these constructs” (p. 223). Overall, Sternberg et al. conclude that “tacit knowledge appears to reflect a single underlying ability, which [they] label practical intelligence” (p. 223). Sternberg et al. do caution that although there is excitement about the promise of this new generation of measures of practical intelligence, they “are the first to admit that existing evidence for the new measures does not yet match that available for traditional cognitive-academic tests. Consequently, the use of both kinds of measures explain more variance in performance than reliance on either kind alone” (p. 224).
The work of Sternberg and his colleagues has provided the most useful insights over time into different ways of framing intelligence in adulthood. First, although the work discussed is more widely used with children, the theory building, research, and applications have also been used with a variety of adult groups in systematic ways. Therefore, there is a twenty-year research history that provides a different level of credibility to this work than to that of Gardner, or, as we next explore, to the concept of emotional intelligence. For educators of adults it provides rich evidence that adult intelligence is much more than academic abilities and measures on the more traditional IQ tests, but also encompasses what many of us have believed it to include all along: everyday or practical intelligence. Second, Sternberg and his colleagues have provided us with initial inventories of both successful and practical intelligence. Although, as was discussed previously, additional validation studies need to be completed on these inventories, we hope that at some point they will be as accepted as the current traditional battery of tests of intelligence in adults. And finally, Sternberg and his colleagues have added their voices to those who have said that intelligence can be taught (see Grotzer & Perkins, 2000 , for an overview) and offer resources that can be used with adults in the instructional process (for example, Sternberg, 1986a , 1988 , 1997).
Emotional Intelligence
The term emotional intelligence became almost a household word with the publication of Goleman's popular book Emotional Intelligence (1995). Goleman's suggestion that “emotional intelligence can be as powerful and at times more powerful than IQ” (p. 24) created excitement especially among practitioners. Grounding his work in the new discoveries of the emotional architecture of the brain, Goleman asserts that we have two very different ways of knowing—the rational and the emotional—which are, for the most part, intertwined and “exquisitely coordinated; feelings are essential to thought, thought to feelings” (p. 9). Yet, in Goleman's beliefs, it is the emotional mind—in his terms, emotional intelligence—that is the major determiner of success in life. His model of emotional intelligence has five primary domains, which he attributes to the earlier model of Salovey and Mayer (1990) : knowing one's emotions, managing one's emotions, motivating oneself, recognizing emotions in others, and handling relationships. Goleman believes that self-awareness of one's feelings is the key to emotional intelligence, but one must also be attuned to the emotions of others.
Both Salovey and Mayer's (1990) and Goleman's (1995) descriptions of how adults might display their emotional intelligence are similar to Gardner's concept of personal intelligence. For example, all the authors speak to the need for people to make personal connections and be empathetic as well as to have access to their own internal feelings. In addition, their ideas about emotional intelligence are echoed in Sternberg's list of the characteristics and attributes of people who display successful intelligence.
Although Goleman's work has been quoted and used most often as a base for practice with both children and adults, there is little if any empirical evidence to support the majority of his basic assertions about emotional intelligence. Rather, as observed by Mayer, Salovey, and Caruso (2000) and Brody (2004) , Goleman's very strong claims on emotional intelligence are based primarily in proprietary research and not published in peer-review journals. In addition, Goleman ascribes his five-domain model of emotional intelligence as one that was conceptualized by Salovey, citing an earlier work of Salovey and Mayer (1990) , as his source. However, in our review of the original source for that model it was our observation that Goleman's model is not a good representation of the work of either the original model Salovey and Mayer proposed (1990) or of their more recent work ( Mayer & Salovey, 1997 ; Mayer, Salovey, & Caruso, 2000 ). In essence, the Mayer and Salovey model has four branches: “(a) perceiving emotions, (b) using emotions to facilitate thought, (c) understanding emotions, and (d) managing emotions” ( Mayer & Salovey, 1997 , as cited by Salovey & Pizarro, 2003 , p. 263). Although some of the language is similar to that of Goleman's description of emotional intelligence, the actual meanings are quite different. First, Mayer and Salovey's work is situated in a rich body of both theory and research. Second, the Mayer and Salovey model has become foundational for some highly sophisticated work on emotional intelligence that both these authors and other scholars continue to revise and use in their research ( Mayer, Salovey, & Caruso, 2000 ; Palmer, Gignac, Manocha, & Stough, 2005 ; Salovey & Pizarro, 2003 ).
In addition to the work completed on building theories and models of emotional intelligence, there is also work done in developing measures of this construct ( Bar-On, 1997 ; Simmons & Simmons, 1997 ; Mayer, Salovey, & Caruso, 2002 , 2003 ). The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) has received the greatest scrutiny. For example, Palmer, Gignac, Manocha, and Stough (2005) have recently completed a psychometric evaluation of the MSCEIT Test Version 2. Two major conclusions resulted from their study: (1) “the reliability of the MSCEIT at the total scale, area, and branch levels was found to be good” (p. 1); and (2) there is a need for the “addition of valid items to the current subscales, as well as the creation of more subscales in general” (p. 21).
Still others have explored the practical application of emotional intelligence in the workplace ( Weisinger, 1998 ; Opengart, 2005 ; McEnrue & Groves, 2006 ). Opengart (2005) conducted a literature search on two very different but related concepts: emotional intelligence and emotional work. She concluded that employees need to have both the capacity to act in emotional situations (that is, emotional intelligence) and in-depth knowledge of how their specific place of employment allows for the expression of emotion and in what ways. McEnrue and Groves (2006) have provided an excellent review and critique on current tests on emotional intelligence used in the workplace. They are advocating using the MSCEIT “on the basis of its psychometric properties and HRD application potential” (p. 38) as the test of choice at this time, although they acknowledge the test is still undergoing further refinement.
Even though the writings and research on emotional intelligence in adulthood have made us think about the importance of emotion to learning, we need to be mindful that this concept of intelligence has little empirical evidence to support it as a separate construct of intelligence. Therefore, we should not consider emotional intelligence as a given fact, nor design programs that teach others how to develop and use a certain “type” of emotional intelligence. Rather, we should continue to critically explore the many ways that emotional intelligence has been presented and reflect on how these might enhance our practice as educators of adults.
We move next in this section to a discussion of the contextual perspective of intelligence. There is some overlap among researchers who include contextual components in their theories and models. Representative theories and models of intelligence where this overlap can easily be seen are successful intelligence ( Sternberg, 1997 ), practical intelligence ( Sternberg et al., 2000 ; Wagner, 2000 ), and emotional intelligence ( Mayer & Salovey, 1997 ; Salovey & Pizarro, 2003 )
The Contextual Perspective of Intelligence
Acknowledging the contextual dimension of intelligence in adulthood moves our thinking beyond the realm of individual learners. Inside the broad framework of this perspective, two main threads emerge. The first thread is that intellectual abilities lie at the intersection of the mind and the many changes we experience over time in our everyday lives. For example, many of us have wondered why some people can be successful in more than one employment setting, even when those settings are radically different, while others fail miserably when they change their places of employment, even when they are doing similar work. One explanation that is often given is that people who succeed across settings have the capacity to scan and adapt to new environments. Unless an individual is able to understand and actively participate in new situations, a contextual theorist would observe, being cognitively competent internally may make little, if any, difference in that person's success in most realms. In essence, the contextual perspective captures the adaptive functions of intelligence—being able to act intellectually in a number of different contexts, based on the accumulation of both generalized and specialized knowledge and abilities ( Berg, 2000 ). Berg (2000) advocates that this process of adaptation should be dynamic, in which individuals’ intellectual “abilities and processes as well as the context are simultaneously shaped” (p. 127). Berg also observes that research on the intersection of the mind and our everyday experiences within the contextual framework “is in its relative infancy compared with the work on individual abilities and processes that reside within the individual” (p. 128).
The second thread in the contextual framework is based on the assumption that intelligence often has different meanings to different social, ethnic, and cultural groups ( Davidson & Downing, 2000 ; Luttrell, 1989 ; Serpell, 2000 ; Sternberg, 2004 ). As Davidson and Downing (2002) state: “What is considered to be intelligent behavior in one culture is sometimes thought to be rather idiotic in other cultures” (p. 40).
In line with this thinking, Kohl de Oliveira (1995, p. 245) notes: “Individuals, growing up in their cultural settings, develop their own conceptions about intellectual competence, acquisition and use of cognitive abilities, and organization of these abilities within different situations.” For example, respondents in Luttrell's study (1989, p. 37) of working-class Black women and White women judged people as intelligent by their ability “to cope with everyday problems in an everyday world.” In other words, they saw using common sense as an important intellectual skill. But even in their definitions of common sense, each group described the formulation and value of this commonsense know-how very differently. White women valued the commonsense knowledge of working-class men, such as manual and craft knowledge, more highly than their own intuitive knowledge springing from their domestic responsibilities. In contrast, Black women viewed as important the knowledge and abilities they gained through caretaking and domestic work. In addition, working-class Black women considered their racial identity and relationships with “extended kin” and the Black community as critical to both what they knew and how they used this knowledge.
Serpell (2000) has raised a very different kind of cultural issue: the culture of academic scholars who possess incredible power over those who try to break out of the mainstream way of conceptualizing and studying intelligence. More specifically, he addresses how a “culturally particular” conception of intelligence, in this case one that is dominant in contemporary Western, industrialized societies, continues to be the prevailing view of how intelligence is defined and researched. Troubling are Serpell's (2000) observations, similar to ones made earlier in this chapter, that this cultural paradigm, for example, “informs the development of most of the standardized tests in the United States, which in turn have emerged from a tradition that has dominated the design of intelligence tests elsewhere around the world” (pp. 567–568). In his discussion of an editorial with fifty-two signatures published in the journal Intelligence ( Gottfredson, 1997 ), Serpell critiques three significant cultural themes raised in the editorial that, from the perspective of the editorial's signatories, drive the majority of the research in intelligence: “decontextualization, quantification, and biologization” ( Gottfredson, 1997 , as cited by Serpell, 2000 , p. 568). We agree with Serpell's intriguing critique of these themes, and also offer our own observations. We find the first theme especially problematic because there are researchers, especially in the last two decades, who have argued that historical, sociocultural, and biographical contexts are central to the study of intelligence in adulthood ( Schaie, 1994 ; Sternberg, 2003b ; Sternberg et al., 2000 ). We also question the second theme of whether all forms of intelligence can or even should be quantifiable. In addition, although the biological perspective, the third theme, may hold great promise for a better understanding of intelligence, we cannot state for sure that this knowledge will be useful in our practice as educators of adults.
Other scholars have crossed the boundaries of Western culture, through cross-cultural studies, to gain a clearer understanding of how culture affects the way intelligence is defined. Sternberg et al. (2000) , for example, describe a number of studies Sternberg and others conducted in Asia and Africa. The groups studied were quite varied in their backgrounds, countries of origin, and the type of environments in which they lived, ranging from adults residing in cities in Taiwan to villagers in rural areas of Africa. Although the populations differed in so many aspects, there was one main similarity among these groups—a stronger emphasis in both African and Asian cultures on social aspects of intelligence “to a much greater extent than in the conventional Western view” (p. 17). Even though this greater emphasis existed, “these cultures still recognize the importance of the cognitive aspects” (p. 17) of intelligence.
Issues of race, ethnicity, and social class, in addition to culture, are also studied. Kohl de Oliveira (1995, p. 262), for example, in her longitudinal study of how adults in a favela (squatter settlement) in the city of São Paulo, Brazil, understand intelligence is one example of a study that takes into account social class as well as culture. She found that her respondents “characterized intelligent people as those who are able, basically, to ‘make things,’ to create concrete products with their own hands: build houses, do woodwork, do mechanical work, paint, make objects in straw, ceramics, and so on.” These people, who were living in a squatter settlement, defined intelligence as the ability to cope with their everyday lives, which in essence meant possessing the skills to make things with their own hands and having the ability to learn easily and quickly things that could assist them in their daily survival.
Sternberg (2004) , as editor of a recent handbook, The International Handbook of Intelligence, has provided us with a wide variety of examples of cross-cultural studies on intelligence from many regions of the world. He includes studies that focus on theory, research, and testing in the Nordic countries, Israel, Turkey, and Japan. In addition, other authors explore whether it is possible to study intelligence without using the concept of intelligence, if diligence can make people smart, and the validity and usefulness of local versus universal models and theories of intelligence.
Intelligence, Aging, and Adult Learning
Among the many new ideas about intellectual functioning in adulthood, four surface as the most intriguing and useful to educators. The first is that the individual differences approach to intelligence continues to be the dominant paradigm in the study of adult intelligence. In essence, most of our knowledge about intelligence in adulthood, including the effects of the aging process on intelligence, is still grounded in the more traditional measures of IQ. Our hypothesis, as stated earlier, is that many educators of adults may not be aware of the enormous influence that intelligence, as defined from the individual differences approach, has had on adult lives. For example, some adults were tracked into ability groups early in their schooling days through these types of IQ tests, which may have lifetime effects on how they and others perceive their ability to learn. In addition, other educators and adults alike have believed for a long time that, as adults age, they really cannot think as well as they once did. For these people this premise may be a “fact of life” that becomes a self-fulfilling prophecy, no matter what evidence is presented to the contrary.
The second development is the expansion of alternative conceptions of adult intelligence. Adults are especially attracted to the work of Gardner on multiple intelligences and Sternberg's notion of practical intelligence, because these ideas resonate with their adult lives. These alternative perspectives on adult intelligence have great potential for assisting adult educators and learners to think differently about what it means to be intelligent. For example, “unschooled adults” often view themselves as not very bright. Yet, in telling stories of some of their favorite activities they often describe hobbies or other tasks that are quite complex and require higher-order thinking. Assisting these individuals in understanding what practical intelligence is all about might change their own self-image as learners.
Third, Sternberg (1996c, 1997) has also challenged us to think in very different ways about how individuals and the circumstances in which they find themselves interact to shape intellectual functioning in adulthood. He offers a novel illustration to help us gain a clearer picture of what he means by “the mind in context”: the “luck” and “whoops” factors ( Sternberg, 1994b ). Each of us is born with different gifts and into different circumstances. Some of us are lucky enough to find ourselves in places where our gifts have been prized and nurtured (the luck factor), while others, no matter what their individual efforts, are never recognized or are blocked by circumstances beyond their control (the whoops factor). As the world around us becomes more complex, so does the entanglement of the whoops with the luck factors. What may be termed a luck factor one day may often without warning become a whoops factor the next. The truly intelligent adult must be able to grapple with these often paradoxical situations, which can become highly frustrating and even daunting to those caught up in tragic events. We think of the many families who were left homeless and jobless as a result of Hurricane Katrina. Many of them have had to progress up a very steep learning curve to get back on their feet, often in circumstances that were at best tolerable, but often horrible. Those who have made their way back to a life of some normalcy are excellent examples of adults who display high levels of intellect—and also, perhaps, have a little luck along the way.
Fourth, researchers such as Schaie (1994, 1996a, 1996b) and Sternberg (1986a, 1986b; Sternberg et al., 2000 ) are creating a clearer understanding of how adults can both retain and even enhance their intellectual abilities as they age. These researchers view adult intelligence as consisting of a number of factors or components. Sternberg, for example, identifies people who really “shine”—that is, are highly intelligent—as those who can weave their academic know-how, however it was learned, their creativity, and their “street smarts” into meeting life “head-on,” no matter the circumstances. Based on this definition, very different strategies for keeping one's intelligence intact are needed than when intelligence is viewed primarily as academic or mental ability. Therefore, based on the varying definitions of intelligence, adult educators need to think carefully about which intellectual abilities might be the most useful for adults, both young and old, to have addressed by educational interventions.
To ensure that they continue to maintain their intellectual functioning, learners themselves can take part in both informal and formal educational programs aimed at keeping their intellectual capacities intact. Adult educators can offer formal learning experiences, grounded in a solid knowledge base about intelligence and aging, while also providing advice to learners on useful resources they might consult. In addition, Peterson and Masunaga (1998) and Ramey and Ramey (2000) advocate that we need to expand our role in educational policies related to learning in adulthood, and more specifically, in policies that speak directly to the intellectual functioning of adults. A basic assumption that influences Ramey and Ramey's commitment in this arena is that all citizens in a democratic society are responsible for acting intelligently in their roles as voters, members of governing boards, and spokespeople for specific causes related to intellectual functioning in adulthood. Examples of specific issues are to ensure that IQ tests used as part of a major policy initiative for adults are appropriate and valid and that public funding is adequate to meet the needs of older adults for specific interventions to maintain their intellectual capacities.
Summary
In this chapter we discussed the more traditional approaches to intelligence, including the biological, the individual differences, and the cognitive processes approaches, which have been foundational to our thinking about adult intelligence. The most often used paradigm among these traditional approaches is the individual differences approach, which assumes that intelligence is a measurable quantity. First conceptualized from this approach as a single factor of general ability, the construct has broadened to include the notion that there are multiple factors of intellectual ability, such as those proposed by Horn and Cattell (1967) , and Thurstone and Thurstone (1941) . Commonly used tests of adult intelligence that fit into this psychometric tradition include the Wechsler Adult Intelligence Scale and the Primary Mental Abilities test. The three issues that have surfaced with the use of these types of tests are what they measure, the inclusion of timed items, and the social and policy implications of IQ scores.
The question of whether adults retain their intellectual abilities as they age has not yet been definitively answered. Set primarily within the individual differences perspectives, three key factors on which the age and intelligence controversies center are defining the concept of intelligence, delineating the parameters of aging, and choosing which research designs and tests to use to measure intelligence. Some researchers contend that intellectual functioning is a process of irreversible decline. However, most scholars agree that intelligence either remains relatively stable through the adult years, with substantial intellectual changes occurring only very late in life, or that intelligence declines in some respects, remains stable in others, and may even increase in some functions, depending on a person's educational level, life experiences, and overall health. In addition, a number of variables reducing the risk of intellectual decline in old age have been isolated, such as living in favorable circumstances and maintaining substantial involvement in activities.
Challenges to the individual differences approach have come primarily from scholars who question whether what is measured as intelligence through this tradition presents a comprehensive picture of intellectual abilities, has any relationship to real-world or practical intelligence, and the effects that context has on intelligence. Three of the most prominent theorists who represent this alternative view of intelligence are Gardner (1999b) , Sternberg (1985, 1997, 2003b), and Mayer and Salovey (1997) . The contextual perspective on intelligence, which often includes the notion of practical and emotional intelligence, recognizes the importance of the intersection of the mind and the outside world as critical in gaining a clearer understanding of intelligence. Acknowledging this perspective means that intelligence has been defined differently by people of varying cultural backgrounds, social classes, and ethnicity.
The chapter concluded with an exploration of four ideas about intellectual functioning in adulthood that are particularly important for educators of adults: the continued predominance of the individual differences approach to the study of intelligence in adulthood; the expansion of alternative conceptions of adult intelligence; how individuals and the circumstances they find themselves in interact to shape intellectual functioning in adults; and a clearer understanding of how adults can retain and enhance their intellectual abilities, including the roles learners and adult educators can play using instructional and policy interventions.