Intelligence
::''For other uses, see
Intelligence (disambiguation)Intelligence is a property of
mind that encompasses many related
mental abilities, such as the capacities to
reason,
plan,
solve problems, think
abstractly, comprehend ideas and
language, and
learn.
Although many regard the concept of intelligence as having a much broader scope, for example in
cognitive science and
computer science, in some schools of
psychology, the study of intelligence generally regards this trait as distinct from
creativity,
personality,
character, or
wisdom.
At least two major "consensus" definitions of intelligence have been proposed. First, from "Intelligence: Knowns and Unknowns" a report of a task force convened by the
American Psychological Association in 1995:
Individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought. Although these individual differences can be substantial, they are never entirely consistent: a given person's intellectual performance will vary on different occasions, in different domains, as judged by different criteria. Concepts of "intelligence" are attempts to clarify and organize this complex set of phenomena. [
1]
A second definition of intelligence comes from "Mainstream Science on Intelligence", which was signed by 52 intelligence researchers in 1994:
a very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings—"catching on", "making sense" of things, or "figuring out" what to do. (reprinted in
Intelligence Gottfredson, 1997, p. 13) [
2]
Individual intelligence experts have offered a number of similar definitions.
*
David Wechsler: "... the aggregate or global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment."
*
Cyril Burt: "...innate general cognitive ability."
*
Howard Gardner: "To my mind, a human intellectual competence must entail a set of skills of problem solvingâ€"enabling the individual to resolve genuine problems or difficulties that he or she encounters and, when appropriate, to create an effective productâ€"and must also entail the potential for finding or creating problemsâ€"and thereby laying the groundwork for the acquisition of new knowledge."
*
Herrnstein and
Murray: "...cognitive ability."
*
Sternberg and Salter: "...goal-directed adaptive behavior."
Main articles: IQ, General intelligence factorDespite the variety of concepts of intelligence, the most influential approach to understanding intelligence (i.e., with the most supporters and the most published research over the longest period of time) is based on
psychometric testing.
Intelligence, narrowly defined, can be measured by intelligence tests, also called IQ (intelligence quotient) tests. Such intelligence tests take many forms, but the common tests (
Stanford-Binet,
Raven's Progressive Matrices,
Wechsler Adult Intelligence Scale,
Wechsler-Bellevue I, and others) all measure the same dominant form of intelligence,
g or "
general intelligence factor". The abstraction of
g stems from the observation that scores on all forms of cognitive tests
correlate positively with one another.
g can be derived as the principal factor from cognitive test scores using the method of
factor analysis.
In the psychometric view, the concept of intelligence is most closely identified with
g, or Gf (
"fluid g"). However, psychometricians can measure a wide range of abilities, which are distinct yet correlated. One common view is that these abilities are hierarchically arranged with
g at the vertex (or top, overlaying all other cognitive abilities).
Intelligence, IQ, and g
Intelligence,
Intelligence quotient (IQ), and
g are distinct.
Intelligence is the term used in ordinary discourse to refer to cognitive ability. However, it is generally regarded as too imprecise to be useful for a scientific treatment of the subject. The
intelligence quotient (IQ) is an index calculated from the scores on test items judged by experts to encompass the abilities covered by the term
intelligence. IQ measures a multidimensional quantity: it is an amalgam of different kinds of abilities, the proportions of which may differ between IQ tests. The dimensionality of IQ scores can be studied by factor analysis, which reveals a single dominant factor underlying the scores on all IQ tests. This factor, which is a hypothetical construct, is called
g. Variation in
g corresponds closely to the intuitive notion of
intelligence, and thus
g is sometimes called
general cognitive ability or
general intelligence.
Criticisms of the psychometric approach
Critics of the psychometric approach, such as
Robert Sternberg (who formulated the
The Triarchic Theory of Intelligence), point out that people in the general population have a somewhat different conception of intelligence than most experts. In turn, they argue that the psychometric approach measures only a part of what is commonly understood as intelligence. Other critics, such as
Sir Arthur Stanley Eddington, argue that the equipment used in an experiment often determines the results and that proving that e.g. intelligence exists does not prove that current equipment measure it correctly. Sceptics often argue that so much scientific knowledge about the brain is still to be discovered that claiming the conventional
IQ test methodology to be infallible is just a small step forward from claiming that
Craniometry was the infallible method for measuring intelligence (which had scientific merits based on knowledge available in the nineteenth century).
Most experts accept the concept of a single dominant factor of intelligence, general mental ability or
g, while others argue that intelligence consists of a set of relatively independent abilities (
American Psychological Association task force report, Gottfredson 1998). The evidence for
g comes from factor analysis of tests of cognitive abilities. The methods of factor analysis do not guarantee a single dominant factor will be discovered. Other
psychological tests which do not measure cognitive ability, such as
personality tests, generate multiple factors.
Proponents of multiple-intelligence theories often claim that
g is, at best, a measure of academic ability. Other types of intelligence, they claim, might be just as important outside of a school setting.
Yale psychologist Robert J. Sternberg has proposed a
Triarchic Theory of Intelligence. Harvard psychologist
Howard Gardner's
theory of multiple intelligences breaks intelligence down into at least eight different components: logical, linguistic, spatial, musical, kinesthetic, naturalist, intra-personal and inter-personal intelligences. Daniel Goleman and several other researchers have developed the concept of
emotional intelligence and claim it is at least as important as more traditional sorts of intelligence. These theories grew from observations of human development and of brain injury victims who demonstrate an acute loss of a particular cognitive function without showing any loss in other cognitive areas.
In response,
g theorists have pointed out that
g's
predictive validity has been repeatedly demonstrated, for example in predicting important non-academic outcomes such as job performance (see
IQ), while no multiple-intelligences theory has shown comparable validity. Meanwhile, they argue, the relevance, and even the existence, of multiple intelligences have not been borne out when actually tested (Hunt 2001). Furthermore,
g theorists contend that proponents of multiple intelligences (e.g. Sternberg, Gardner) have not disproved the existence of a general factor of intelligence (Kline, 2000). The fundamental argument for a general factor is that test scores on a wide range of seemingly unrelated cognitive ability tests (such as sentence completion, arithmetic, and memorization) are positively
correlated: people who score highly on one test tend to score highly on all of them, and
g thus emerges in a
factor analysis. This suggests that the tests are
not unrelated, but that they all tap a common factor.
Researchers in the field of human intelligence have encountered a considerable amount of public concern and criticism - much more than many scientists would be accustomed to or comfortable with (for examples, see
Gottfredson, 2005). Some of the controversial topics include:
* The relevance of psychometric intelligence to the common-sense understanding of the topic.
* The importance of intelligence in everyday life (see
IQ).
* The genetic and environmental contributions to individual variation in intelligence (see
Nature versus nurture).
* Differences in average measured intelligence between different groups and the source and meaning of these differences (see
Race and intelligence and
Sex and intelligence).
Stephen Jay Gould was an important popular critic of intelligence theory. In his book
The Mismeasure of Man, Gould made the following claims about intelligence:
*Intelligence is not measurable.
*Intelligence is not innate.
*Intelligence is not heritable.
*Intelligence cannot be captured in a single number.
However it is reported that he has largely ignored at least a decade of important recent research and draws from outdated information to validate his conclusions. Some of Gould's criticisms are aimed at
Arthur Jensen. Jensen alleges Gould made several misrepresentations of Jensen's work.
*Coward, W.M. and Sackett, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation.
Journal of Applied Psychology, 75:297–300.
*Gardner, H., Kornhaber, M. and Wake, W. (1996). Intelligence: Multiple Perspectives. Fort Worth: Harcourt Brace College Publishers.
*
Gottfredson, L. S. (Ed.) (1997). Intelligence and social policy.
Intelligence, 24(1). (Special issue)
PDF*Gottfredson, L. S. (1998). The general intelligence factor.
Scientific American Presents, 9(4):24-29.
PDF*Gottfredson, L. S. (2005). Suppressing intelligence research: Hurting those we intend to help. In R. H. Wright & N. A. Cummings (Eds.), Destructive trends in mental health: The well-intentioned path to harm (pp. 155-186). New York: Taylor and Francis.
Pre-print PDF PDF*
Hawkings, Jeff (2005).
On intelligence, Times Books, Henry Holt and Co. ISBN 0-8050-7456-2
*Hunt, E. (2001). Multiple views of multiple intelligence. [Review of Intelligence Reframed: Multiple Intelligences for the 21st Century.]
Contemporary Psychology, 46:5-7.
*Hunter, J.E. and Hunter, R.F. (1984). Validity and utility of alternate predictors of job performance.
Psychological Bulletin, 96(1):72-98.
*
Jensen, A.R. (1998).
The g
Factor. Praeger, Connecticut, USA.
*Kline, P. (2000).
A Psychometrics Primer. London: Free Association Books.
*McClearn, G. E., Johansson, B., Berg, S., Pedersen, N. L., Ahern, F., Petrill, S. A., & Plomin, R. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science, 276, 1560-1563.
* Michael A. McDaniel, Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence, Intelligence, Volume 33, Issue 4, July-August 2005, Pages 337-346. [
3]
*
Murray, Charles (1998). Income Inequality and IQ, AEI Press
PDF*Noguera, P.A. (2001). Racial politics and the elusive quest for excellence and equity in education.
In Motion Magazine article*R. Plomin, J. C. DeFries, G. E. McClearn, M. Rutter,
Behavioral Genetics (Freeman, New York, ed. 3, 1997).
* Terman, L. (1916).
The Uses of Intelligence Tests.*
Educational psychology*
Systems intelligence*
Artificial intelligence*
General remarks: cognitive and other intelligences*
APA Task Force Report, "Intelligence: Knowns and Unknowns"**
Press Release: APA Task Force Examines the Knowns and Unknowns of Intelligence*
The Wall Street Journal: Mainstream Science on IntelligencePDF*
Human Intelligence*
One Intelligence or Many? Alternative Approaches to Cognitive Abilities*
What composes intelligence? Discussion on the composition of intelligence.
*
Intelligence: misuse and abuse of statistics*
IQ Since "The Bell Curve" by Christopher F. Chabris*
Does IQ Matter? Christopher F. Chabris & critics*
The cognitive-psychology approach vs. psychometric approach to intelligence*
Dr. McGrew's Intelligence Blog*
Intelligence quotations*
Relative Intelligence | E-Book | The relativity of intelligence as a basic biological principle of fitness for life*
An approach to high-intelligence 
