New ideas about intelligence
This is a longer than usual post because there is an article and two responses. All are available as open text. Unlike some of my posts that try to offer immediately helpful information, this one is more historical and theoretical, but, in my view, has important implications. First, Ackerman (2023) published “Intelligence … moving beyond the lowest common denominator” in American Psychologist. Here’s the highly edited article with some information in bold:
Traditional measures of intellectual abilities focus on knowledge that is common to a population. These assessments may be appropriate for children, but they do not capture the day-to-day intellectual functioning of most adults. Assessing knowledge and skill repertoires may improve understanding of development, maintenance, and decline of intelligence in adolescence and adulthood. Despite a century of use in assessing children for predicting academic success, IQ theory and assessments largely overlook the intellectual repertoires of adolescents and adults that are not common, including declarative, procedural, and tacit knowledge. Such knowledge and skill repertoires are essential elements of adult intellectual life and livelihood.
Even though intelligence and intelligence-related assessments are a ubiquitous connection between members of the population and applications of psychology, they have become increasingly controversial. First, such controversies have resulted in making testing optional at an increasing number of secondary schools and higher educational institutions. Second, this past century has also witnessed vigorous discussions of group differences in intelligence and related measures (e.g., based on gender, socioeconomic status, race, and ethnicity) that have not been satisfactorily resolved. Third, a general dissatisfaction has been expressed in both the scientific and lay community about the adequacy of intelligence assessments, given that they typically represent a relatively narrow sampling of intellectual capabilities. Fourth, there are important questions about intellectual development from early childhood through old age and the utility of IQ measures as predictors of everything from longevity to lifelong earnings. Finally, there is keen interest in the relations between nonability traits and intellectual development and intellectual behaviors.
One consequence of adopting the psychological method is that significant portions of the child’s intellectual repertoire of knowledge and skills are not sampled within the assessment of intelligence. As proposed by Binet and Simon (1905/1973), the alternative to the psychological method is the pedagogical method. The pedagogical method of assessing intelligence places an emphasis on knowledge. Ryle (1949/2000) described two major types of knowledge, knowing that and knowing how. Knowing that is typically identified as “declarative knowledge” and is essentially the body of factual knowledge of the kind one finds in an encyclopedia. Knowing how is called “procedural knowledge.” Developing assessments of procedural knowledge is a more complex process than assessing declarative knowledge. First, procedural knowledge is not usually as “discrete” as declarative knowledge, in that each procedure typically involves multiple steps. Ultimately, to describe an individual’s intellectual repertoire from a pedagogical perspective, it is necessary to (a) identify the breadth and depth of the individual’s declarative knowledge; (b) assess the range and level of expertise of his/her procedural skills; (c) assess tacit knowledge capabilities; and (d) identify the processes needed to engage these kinds of intellectual functioning that are needed to perform tasks.
The traditional approach is to administer an IQ test and make a direct comparison of their relative IQ scores. However, the IQ test provides little useful information about the cognitive, perceptual, and psychomotor knowledge and skills of [any] two individuals. The IQ test also does not provide information regarding what other sources of declarative, procedural, and tacit knowledge for these respective individuals. That is, knowledge that could determine whether each of them is capable of other intellectual feats (e.g., knowledge of music, art, other sciences, but also plumbing, electronics, gardening, health, parenting, current events). In addition, if one of them is also an accomplished musician or artist, while the other is not, that part of their respective repertoires should be included in our consideration of their respective levels of intellect.
I offer an integrated definition of intelligence that explicitly takes account of the knowledge aspects of intellectual functioning: Intelligence is the entire repertoire of knowledge (declarative, procedural, and tacit) and skills available to the individual to solve tasks that demand cognitive, perceptual, and/or psychomotor processing and behaviors, and the processes to acquire new knowledge and skills. That is, while acknowledging the value of the psychological method of assessing intelligence especially for children, the proposed definition leverages the pedagogical method and includes those qualities of individuals, especially adolescents and adults, that represent the capability of individuals to carry out a variety of occupational and other tasks necessary for career success, day-to-day functioning, and other activities.
The choice of the psychological method over the pedagogical method for young children is a reasonable one, especially at school entry, because that approach is likely to reduce the influences of socioeconomic status related to the child’s exposure to reading and writing in the home. However, as the child progresses through the early grades of school, individual differences in reading and writing skills in particular likely play a more important role in the development and expression of intellect. As students complete (or leave) high school, the vocational and avocational (e.g., hobbies) knowledge and skills they may acquire are even more diverse than they are in high school.
Research findings with intelligence assessments grounded in the psychological approach has led to an implicit acknowledgment that traditional IQ-type assessments have good levels of criterion-related validity for children, but declining validity for the educational and occupational success of adolescents and adults. In contrast, augmenting traditional IQ assessments with relevant assessments of the knowledge and skill repertoire of individuals can be expected to have higher validity for predicting educational and occupational outcomes for adolescents and adults, compared to predicting educational outcomes for children. One of the corollaries of the proposed integrated perspective to move away from the lowest common denominator assessment of intelligence pertains to the length of time and effort that will be required to assess intelligence among adolescents and adults.
Other assessment techniques could be explored to reveal individual differences in domain-specific knowledge, ranging from self-assessments to experience-sampling, in order to determine the use of domain knowledge or engagement of procedural skills. The preceding treatment of issues surrounding the theory and assessment of intelligence leads to the conclusion that in order to describe the intelligence of individuals (especially for adolescents and adults), one needs to construct intelligence portfolios that depict the breadth and depth of an individual’s knowledge and skills.
These assessments are to be indicators of the current state of the individuals—not a direct measure of potential, because potential can only be imperfectly predicted from an individual’s current repertoire, the current and likely future state of educational/training technologies and techniques, the level of cognitive investment the individual is likely to expend over the rest of his/her life in terms of maintaining and expanding his/her repertoire of knowledge and skills, and the effects of aging.
The main proposition of age differentiation theory (see Anastasi, 1983) is that during childhood, intelligence is largely amorphous and dominated by a general factor. As children develop into adolescence and early adulthood, the underlying component factors emerge as more differentiated. [A] corollary from the proposed perspective is that studies of age differentiation to date have not adequately assessed intellectual abilities beyond those that assess knowledge and skills that are largely common to the population of individuals sampled (the lowest common denominator). That is, there are no studies of age differentiation that include broad and deep assessments of occupational knowledge and skills from adolescence to older adult populations.
Using the lowest common denominator approach, where intelligence is narrowly defined as fluid intelligence or working memory, multiple sources of research have suggested that middle-aged and older adults are victims of a steep decline in intellectual capabilities, compared to adolescents and young adults. Yet, large numbers of well-learned or well-trained middle-aged adults are the backbone of modern society, from doctors, nurses, lawyers, plumbers, carpenters, airline pilots, and psychologists.
Moving comprehensively beyond, a lowest common denominator approach is a significant challenge, but efforts can be made in the near-term future that start to approximate the approach. Existing data indicate that AP test scores provide equal or greater valid prediction of grades and time-to-graduate criteria, when compared with SAT scores, even though there may not be commonality among the students on which AP tests were completed. Similar evidence has been obtained on predicting graduate school performance, when comparing Graduate Record Exam (GRE) subject tests against the GRE general tests. The other advantage to these types of assessments over traditional lowest common denominator tests is that they may be used to provide direct feedback to the examinees with actionable information (e.g., the examinee did not have adequate knowledge or skills on various sets of core knowledge in a domain). That is, knowledge deficits may be remedied, even when traditional IQ-type measures might be considered to be highly stable for adolescents and adults.
Arguably, one of the most difficult challenges for both intelligence theory and assessments has been the lack of understanding of tacit knowledge/skills and the resultant lack of measures to adequately assess the range of knowledge and skills that make up this knowledge domain. One consensus view of critical thinking (CT) from a group of experts in philosophy (Facione, 1990) defined “… critical thinking to be purposeful, self-regulatory judgment which results in interpretation, analysis, evaluation, and inference, as well as explanation of the evidential, conceptual, methodological, criteriological, or contextual considerations upon which that judgement is based” (p. 3). From this perspective, it seems reasonable to suggest that CT skills may represent a construct that includes a large amount of tacit knowledge.
As noted by Neisser et al. (1996), the reported validity of traditional intellectual ability measures (general cognitive ability) for predicting job performance tends to range from r = .30 to .50. Schmidt (2002) reported somewhat higher correlations for high-complexity jobs (r = .57) and somewhat lower validities for low-complexity jobs (r = .38). The inference is that traditional measures account for roughly 10%–25% of the individual differences variability in job performance. Many other traits also play a role in determining individual differences in job performance, personality traits, interests, motivation, along with situational press and other influences.
An “intelligent” adult, from the current perspective, is someone who has invested his or her cognitive effort across a significant period of time to develop knowledge and expertise in a chosen occupation and other activities; is actively engaged in both maintaining and expanding his or her repertoire of declarative, procedural, and tacit knowledge; and who chooses to employ CT skills in day-to-day activities when appropriate.
A knowledge and skill repertoire approach to intellectual assessments may ultimately bring new relevance and less controversy the field, compared to the first 100+ years of the Binet–Simon inspired tests. Specifically, by incorporating an individual’s knowledge and skill repertoire into the definition of intelligence, psychology may finally remove the erroneous but persistent, belief among laypeople and some professionals that all of intelligence is a fixed value quantified by the traditional IQ score. The intellectual repertoire may grow as a function of educational, occupational, and avocational learning and practice and may decline through disuse and age-related decline. The individual and society both have roles in maximizing intelligence well beyond the K–12 years.
As I mentioned at the outset, there are two responses. Oswald, Courey & Liu (2023) published “Knowledge, Skills, and Workforce Development: Commentary on Ackerman (2023)” in American Psychologist. Here’s a highly edited summary:
Ackerman (2023) proposed incorporating a more comprehensive range of knowledge and skills into the conceptualization and operationalization of intelligence beyond traditional assessments. In agreeing with and extending this proposition, the current commentary focuses on the specific context of workforce development and highlights three critical considerations: (a) the development of knowledge and skills at different life stages of education and work, (b) the role of social contexts in knowledge and skill acquisition, and (c) quantitative and qualitative approaches to understanding and assessing a broader set of knowledge and skills in light of ongoing changes in the workplace. Overall, we encourage greater research investment in understanding critical educational, organizational, and policy issues pertaining to the future of work.
It is important to note how skills and career development also happen in peer groups who share the same goals and interests. Informal student or employee events, hobbyist meetings, topic-driven webinars, and social media are among a variety of methods for not only developing skills further but also calibrating them with others, while also sharing broader career-related plans, advice, and experiences.
Our final point is an important assumption of Ackerman (2023) that we wish to make explicit: Well-developed measures are critical to providing any data-driven insights about knowledge and skill acquisition. When tests of knowledge and skill are well developed conceptually and psychometrically, they can inform students and employees about their key strengths and developmental needs, in light of their work and career aspirations.
We wholeheartedly agree with Ackerman (2023) on the need for greater investments in research on knowledge and skill acquisition. Such investments will be absolutely essential in order to (a) measure a much wider set of occupational knowledge and skills within student and worker populations that will (b) provide solid data-driven guidance for cultivating knowledge and skills further; (c) coordinate them with the changing demands of the modern workforce; and (d) understand important problems, progress, and promise of the education and the workforce contributing to knowledge and skill gaps across important demographics (e.g., legally protected subgroups of race/ethnicity, women, older workers, the disabled). Conversely, without the information that knowledge and skills assessments provide, inferences about the current national state of education and the workforce become severely limited in all these respects. Imagine how such a broad research investment and program of workforce-oriented knowledge and skills assessment could meaningfully contribute to realizing the potential of students while improving the diversity and talents of the workforce—including future psychologists.
Finally, Sternberg (2023) published “Intelligence is Not the “Entire Repertoire of Knowledge,” but rather the repertoire of adaptive knowledge: Commentary on Ackerman (2023)” in American Psychologist. Here is the highly edited commentary:
Intelligence, historically, has been defined as the ability of an individual to adapt to the environment. Building on this definition, I argue for a concept of adaptive intelligence whereby adapting to, shaping, and selecting real-world environments so as to recognize, define, and solve real-world problems—not just artificial ones—is the core of what constitutes intelligent thought and behavior.
On the one hand, Ackerman’s (2023) definition of intelligence represents a substantial augmentation of, and improvement upon, the conception of intelligence as g, or general intelligence (e.g., Carroll, 1993). Ackerman’s definition recognizes that intellectual performance goes well beyond the knowledge and skills commonly assessed by so-called “IQ tests.”
Although Ackerman’s (2023) definition is an improvement, I suggest it is lacking because it, like many other contemporary conceptions of intelligence, represents a neglect of the fundamental insight of early theorists of intelligence, that intelligence, at its core, is the ability to adapt to the environment. The whole biological basis of intelligence is in giving organisms a selective adaptive advantage. For example, what early humans lacked in physical capacities they made up for in adaptive intelligence, which nevertheless enabled them to survive and even thrive.
Ackerman’s (2023) unselective knowledge accumulation definition appears to treat all knowledge as largely equal parts of this repertoire, but they are not. Some kinds of knowledge are (a) adaptively useful, others, (b) adaptively irrelevant, and still others, (c) adaptively harmful. Adaptively useful information would include things like how to protect oneself (and others) against (a) toxins in the environment, (b) contagious diseases, and (c) crime (e.g., pickpocketing). Adaptively irrelevant information (for most people) would be memorizing, for example, a novel or a random sequence of musical notes. Adaptively harmful knowledge would be absorbing in detail, and also believing, the contents and perhaps acquiring procedural knowledge of how to act hatefully in response to anti-Semitic, anti-Muslim, racist, or generally hate-filled tracts, such as The Turner Diaries or The Protocols of the Elders of Zion, or of contemporary conspiracy theories, such as that vaccinations against COVID-19 actually cause the disease. Such knowledge might actually decrease adaptive intelligence.
The fundamental problem with Ackerman’s (2023) definition, as stated in the article, is that adaptively useful, irrelevant, and harmful information can all be part of the “entire repertoire of knowledge” (p. 285). Greater intelligence is not merely in having knowledge but rather, adaptively, in discerning what knowledge one has is actually true and what knowledge is useful. The risk of a definition such as Ackerman’s is that it fails, as so much schooling does today, to distinguish between adaptively valuable and adaptively questionable or even maladaptive knowledge. What is missing today is not so much acquisition of knowledge, but rather skills for curation of that knowledge. Such curation would be used to determine which knowledge is accurate, which is questionable, and which is false. It is often difficult to judge.
The world faces enormous challenges—global climate change, air and water pollution, pandemics, gross economic disparity, the rise (once again) or ruthless autocrats, and weapons of mass destruction, to name a few. Intelligence needs to be deployed to adaptive solutions, not to just accumulating vast stores of any kind of knowledge, no matter how school or job relevant. As Ackerman (2023) recognizes, critical, creative, practical, and wise thinking are keys to curating knowledge (Sternberg, 2021). Traditional notions of intelligence and Ackerman’s alike, I suggest, are not up to the challenges the humans face right here and now in the struggle for not just individual but also species survival. If we, as a species, use our “vast stores” of knowledge to wipe out ourselves and our potential future generations, were we really intelligent? Intelligence is to be found in the adaptive deployment of knowledge, not merely in its accumulation.
So, if you’re still with me, what I like about this work is its reminder of the limitations of IQ scores if you want to understand adolescents or adults. It also reminds you of some of what you learned a long time ago about such things as declarative, performance, and tacit knowledge. Furthermore, it recognizes the fact that what is needed to be a well-functioning adult entails far more than a specific IQ score. This means that assessing adults takes time and intentionality in responding to referral questions, especially as they relate to the capacity to work and manage activities of daily living.