While it might be appealing to have a single standard by which to compare each individual and to derive statistical data from that standard, some psychologists argue that intelligence is actually a cultural variable. A study by the American Psychological Association gives the example of rural Zambia, where social responsibility is highly valued and, in that society's conception, actually indistinguishable from other intelligence factors, such as ability to learn or think abstractly.
Some psychologists suggest a "multiple intelligences" theory, breaking the types of intelligences into eight categories: linguistic, logical, spatial, musical, introspective, social, physical, naturist. According to Howard Gardner, the first proponent of the theory, most IQ tests focus only on the linguistic and the logical, because these are what schools traditionally are focused on. However, to neglect other manifestations of intelligence because of inadequate IQ tests would be an injustice.
IQ tests have a sometimes dark history and, according to Learning Info's history of the test, had some of their roots in the eugenics movement. While tests today do not play that role, they do separate the "elites" from the "others," and possibly on a non-scientific basis. If the test is truly subjective, based on the test designer's conception of intelligence, then the separation of the supposedly more intelligent from the less intelligent is invalid and inaccurate, especially if a single IQ test is used as the sole means for such classification.
In the end, the IQ test may serve as a useful tool for measuring certain aptitudes, but it is potentially inaccurate and dangerous to use it as the sole tool for such measurement.