The term cognitive ability generally refers to the capacity to mentally process, comprehend, and manip- ulate information—in short, the ability to learn. For example, reasoning deductively or inductively, grasp- ing general principles from observing the behavior of objects, mentally rotating objects in one’s mind, quickly and accurately comprehending what one is reading, and dealing effectively with mathematical concepts are all cognitive abilities. Cognitive abilities largely constitute what most people intuitively call intelligence. Cognitive abilities are also referred to as cognitive aptitudes.
The scientific study of cognitive abilities has a long and sometimes contentious history. However, researchers’ interest has centered on two common themes: the structure of cognitive abilities (i.e., how many are there, and what do they look like?) and the impact of differences in cognitive abilities on out- comes of importance (i.e., what do they predict?).
THE STRUCTURE OF COGNITIVE ABILITIES The debate over the structure of cognitive abilities is perhaps one of the most storied arguments in differen- tial psychology. At the risk of oversimplifying its history, the debate largely centers on the question of whether there is a single general cognitive ability or many independent specific abilities. Today, most sci- entists accept a model of cognitive abilities similar to the one proposed by John B. Carroll. In an exhaustive and remarkable endeavor, Carroll reanalyzed more than 400 data sets spanning more than 60 years of research. His results convincingly demonstrated that the psychometric structure of cognitive abilities is 76———Cognitive Abilities
best described by a hierarchal model with three basic strata or levels. At the apex is a single general cogni- tive ability factor, referred to as g, below which are a small number of narrow abilities, often referred to as group factors, each of which sits, in turn, on top of a large number of task-specific abilities. The primary levels of interest are the top level (g) and the second level, which contains 8 to 10 narrow abilities.
Definition of the gg Factor
The gfactor reflects one’s general ability to learn.
Formally, it is defined as the “eduction of relations and correlates,” that is, the ability to infer or deduce meaningful principles and concepts from abstract and novel situations. The gfactor is reflected in the perva- sive positive correlations among any set of tests or tasks that require any form of cognitive manipulation or processing of information. That is, although more narrow mental abilities (e.g., verbal ability, quantita- tive ability, visual-spatial ability, short-term memory) can be identified, people who are high (or low) on any individual narrow ability tend to be relatively high (or low) on the others. Reliable measures of cognitive abilities are always positively correlated.
Definition of Narrow Abilities
There remains some slight disagreement and uncertainty regarding the exact specification of nar- row abilities. In fact, Carroll himself cautioned that some slight modification or further refinement to those factors may be in order. Nonetheless, the fol- lowing narrow abilities are included in most models of cognitive abilities:
• Fluid intelligence/reasoning: The ability to apply rules and premises to reach a solution; the ability to discover the underlying characteristics that govern problems
• Quantitative reasoning/skills: The ability to reason, either inductively or deductively, with mathematical concepts, relations, and properties; general knowl- edge of mathematical concepts
• Crystallized intelligence: The size and sophistication of one’s vocabulary; the ability to comprehend and communicate orally and use communication skills with fluency; the range of general and acculturated knowledge
• General verbal ability: The ability to recognize and decode words or disguised words; the ability to
comprehend and communicate with clarity of thought and expression in written discourse; general understanding of language rules of (native) language
• Short-term memory: The ability to form and store mental representations of stimuli and then recognize or recall them after a short duration (memory span, visual memory)
• Long-term associative storage and retrieval: The ability to store and recall previously learned material regardless of whether it is meaningful; the ability to rapidly produce series of ideas, words, or other elaborative information related to a specific theme or object; the ability to rapidly produce novel or uncommon connections among stimuli or solutions to problems
• Visual-spatial processing: The ability to mentally manipulate objects or visual patterns, such as men- tally rotating multidimensional objects in space; the ability to quickly discern a meaningful object from partially obscured or vague patterns and stimuli
• Auditory processing: The ability to process speech sounds; phonological awareness; the ability to dis- criminate speech sounds in normal and distorted con- texts; the ability to discriminate tones, tone patterns, pitch, and other variations in sound qualities; the ability to localize sounds in space
• Cognitive processing speed: The ability to rapidly make simple decisions or perform simple tasks; the ability to compare visual symbols; the ability to rapidly manipulate and deal with numbers in ele- mentary ways
PREDICTIVE VALIDITY OF COGNITIVE ABILITIES
That differences in cognitive abilities exist and that they appear to have something to do with differences in a wide array of behaviors has been recognized for several thousand years. Therefore, a wide variety of methods for assessing individual differences in cogni- tive abilities have been developed, and many have proved useful in understanding or predicting behav- iors as varied as academic performance and technical job performance, occupational and economic attain- ment, delinquency, criminal behavior, accident prone- ness, and mortality, to name just a few.
Predictive Validity of gg
A wealth of data has confirmed that g is predictive (at levels of both theoretical and practical signifi- cance) of individual differences in a wide range of Cognitive Abilities———77
academic, occupational, and social outcomes. Of interest to industrial and organizational psychologists, gis consistently the best single predictor of job train- ing performance and technical job performance across a wide range of ages, settings, and domains. There is no job for which gis not at least a moderately strong predictor of technical performance.
For example, meta-analytic estimates place the predictive validity of gfor technical job performance around .50 to .60 and .56 for performance in job train- ing programs. The exact value varies depending on the nature of the job in question, however. For example, the correlation between g and technical performance for managerial and many information-dependent white-collar jobs is typically in the range of .50 to .61.
By contrast, the correlation for manual labor jobs is typically around .25. It is the cognitive complexity of the occupation that moderates the predictive validity of g. In addition, g maintains its predictive validity across experience levels. In fact, some studies show that the predictive validity of g actually increases as experience increases. At first, this may seem counter- intuitive: After all, people with more experience have had the opportunity to learn more and hence acquire greater levels of job-specific knowledge and skills. All things being equal, an employee with greater experi- ence will perform better than an inexperienced employee. However, all things are not equal. It is the ability to profit from experience that is of importance, and g essentially reflects the ability to learn from experience. Those with higher glearn faster; thus, as experience increases, differences in knowledge and skills attributable to gbecome increasing exaggerated.
Predictive Validity of Narrow Abilities Unlike g,the predictive validity of narrow abilities is tied more closely to the nature of the criteria that one seeks to predict. Thus, it is more difficult to speak of generalized findings regarding the predictive valid- ity of narrow abilities. In addition, given the robust- ness of g’s predictive validity, the value of narrow abilities has typically been gauged by their incremen- tal validity. That is, in order to merit attention as prac- tically significant, evidence for the incremental contribution of narrow abilities above and beyond g should be substantial, dependable, and related to meaningful outcomes. However, even the most optimistic interpretation of the existing empirical
literature would fall short of this standard for practical significance. That is, narrow abilities typically do not add significant amounts of incremental predictive validity above and beyondgin the prediction of aca- demic or technical job performance. For example, after accounting for the variance attributable to g, the inclu- sion of the set of narrow abilities typically increases the correlation with technical job performance by less than .05. Thus, the narrow abilities, despite their psy- chological significance, may have only practical sig- nificance in situations in which the range of general ability has been restricted (e.g., among a group of doc- toral graduate students, for whom prescreening pro- duces significant range restriction in g) or in which there is a single, domain-specific criterion to be pre- dicted (i.e., development of reading skills).
On the other hand, there are times when one is less interested in predicting between-person differences in performance and more interested in matching an indi- vidual person’s profile of narrow abilities (i.e., their relative strengths and weakness) with the narrow abil- ity demands of the work or educational environment.
This corresponds to the dominant perspective within the vocational counseling literature. Indeed, it is well- known that g is an insufficient descriptor of work demands; occupations display distinct patterns of narrow ability demands. As such, the assessment of within-person differences in narrow abilities may be especially useful in personnel classification and academic and career counseling.
SUMMARY
Arguably, it is the potential breadth and magnitude of the impact of individual differences in cognitive abil- ities that makes their study of great interest to both scientists and the general public. Although scientific treatment of cognitive abilities did not appear until the late 19th century, theory development and a wealth of empirical data accumulated since then supports two conclusions: (1) The psychometric structure of cogni- tive abilities is best modeled as a three-tiered hierar- chical structure with a general mental ability factor,g, at the apex, and (2) general mental ability is of great functional importance in virtually every aspect of life.
—Charlie L. Reeve
See also Cognitive Ability Tests; Factor Analysis;
Individual Differences 78———Cognitive Abilities
FURTHER READING
Carroll, J. B. (1993). Human cognitive abilities: A survey of factor-analytic studies.New York: Cambridge Univer- sity Press.
Gottfredson, L. S. (1997). Whyg matters: The complexity of everyday life. Intelligence, 24,79−132.
Hunter, J. E., & Hunter, R. F. (1984). Validity and utility of alternative predictors of job performance. Psychological Bulletin, 96,72−98.
Jensen, A. R. (1998). The gfactor: The science of mental ability.Westport, CT: Praeger.
Lubinski, D., & Dawis, R. V. (1992). Aptitudes, skills, and proficiencies. In M. Dunnette & L. M. Hough (Eds.), Handbook of industrial and organizational psychology (Vol. 3, 2nd ed., pp. 1−59). Palo Alto, CA: Consulting Psychologists Press.
Reeve, C. L., & Hakel, M. D. (2002). Asking the right ques- tions about g. Human Performance, 15,47−74.
Schmidt, F. L., & Hunter, J. E. (1998). The validity and util- ity of selection methods in personnel psychology:
Practical and theoretical implications of 85 years of research findings.Psychological Bulletin, 124,262−274.