Modern ability tests produce scores for different areas (e.g., language fluency, three-dimensional thinking, etc.), with the summary score calculated as a some general measure, whose significance is disputed. Significantly, individual subtest scores correlately highly with one another and with between different tests. This kind of analysis has led to the theory that underlying these disparate cognitive tasks is a single factor, term the g factor, that represents the common-sense concept of intelligence.

Opponents argue that it is much more useful to know which are the strengths and weaknesses of a person than to know that he or she holds a measureable superlative on n percent of the populace in some "general intelligence" measure. Such opponents often cite the example of two people with the same overall IQ score but very different ability profiles. However, most people have highly balanced ability profiles. Differences in subscores are greatest among the most intelligent, which may lead them to this misconception.

IQ scores are generally taken as an objective measure of intelligence. Because intelligence is difficult to define, the definition "Intelligence is what the IQ test measures" has been seriously proposed.

While it might be argued that IQ tests encode their creator's beliefs about what constitutes intelligence, analyses of an individual's scores on a wide variety of tests will reveal that they all measure a single common factor and various factors that are specific to each test. Most people also think that creativity plays a significant role in intelligence, but creativity is not measured by IQ tests.

The modern field of intelligence testing began with the Stanford-Binet test. It is worth noting that Alfred Binet, who created the IQ test in 1904, was aiming to identify students who could benefit from extra help in school: his assumption was that lower IQ indicated the need for more teaching, not an inability to learn. Indeed, this interpretation is still held by modern experts.

(The following numbers apply to IQ scales with a standard deviation σ = 15.) Scores between 90 and 110 are considered average—so a person scoring 95 is simply average, not below-average. For children scoring below 80 special schooling is encouraged, children above 135 are "highly gifted". In previous years, scores below 90 were divided into ranges labelled moron, imbecile and idiot, while scores above 150 were labelled genius. Some writers say that such scores outside the range 55 to 145 are essentially meaningless because there are not enough people to make statistically sound statements.

Table of contents

1 Race and IQ 2 Opposition to IQ testing 3 The SAT is an IQ Test 4 Online IQ tests 5 External links

Race and IQ

Opposition to IQ testing

...the abstraction of intelligence as a single entity, its location within the brain, its quantification as one number for each individual, and the use of these numbers to rank people in a single series of worthiness, invariably to find that oppressed and disadvantaged groups--races, classes, or sexes--are innately inferior and deserve their status. (pp. 24-25).

The SAT is an IQ Test

Online IQ tests

• Flynn effect
• Race and intelligence
• Nature versus nurture

• Scientific American: Intelligence Considered
• Scientific American: The General Intelligence Factor
• Wall Street Journal: Mainstream Science on Intelligence