Do IQ Tests Work?
Since starting research for this article, I’ve had a ton of ads for IQ tests of varying degrees of free-ness. What is IQ? What is an IQ test? Does it work?
What is IQ?
IQ stands for “intelligence quotient”. It’s a score from a test that’s designed to measure human intelligence. IQ is an attempt at a concrete definition of “intelligence” and has been used to measure disability and determine job placement, among other things.
What is an IQ test?
An IQ test tries to estimate IQ. IQ tests are traditionally designed with 100 as the mean (average) and 15 as the standard deviation. That means that the average score is 100 and about 2/3 of the population falls between 85 and 115. In other words, if your free online IQ test gives everyone a 130 and above, it’s probably not a real IQ test.
Do IQ tests work?
One advantage of IQ tests is that the results are repeatable, so a particular score is likely an accurate measure of whatever the test is measuring. However, what is the test measuring?
IQ tests seem to measure some forms of intelligence, but leave out other aspects - like creativity and social intelligence - entirely.
Scores have also shown variation between racial groups that are not explained by difference in intelligence, which might mean that the test does not work the same for everyone.
Similarly, IQ metrics were used by the eugenics movement in the US to decide who was worthy of living and reproducing, which is absolutely unacceptable. They have also been used by employers and the military to decide who got promotions and who didn’t, which often served to promote long-standing racial inequality in the US.
Interestingly, IQ test scores have been steadily rising over the last century. Some possible explanations for this: people are getting more comfortable with tests in general, people have better access to good nutrition and therefore better brain growth, and the more stimulating environment (ie TikTok and IG) promote development of these types of intelligence.
The science community seems mixed on what, if anything, IQ tests do. Clinicians use IQ tests as a rough measure of capability. Some scientists feel IQ tests hare helpful for measuring some types of intelligence. And some scientists think they’re completely worthless at measuring intelligence. It seems like IQ tests are the best way we have to measure “intelligence”, whatever that is, but is far, far from perfect.
Sources:
https://en.wikipedia.org/wiki/Intelligence_quotient
https://www.nature.com/scitable/forums/genetics-generation/america-s-hidden-history-the-eugenics-movement-123919444/
https://en.wikipedia.org/wiki/Flynn_effect