Russell Warne has spent many hours scrutinising undergraduate psychology textbooks. As a professor of psychology at Utah Valley University, 鈥� and he found plenty. Some of the worst concerned IQ tests. 鈥淭he most common inaccuracy I found, by far, was the claim that intelligence tests are biased against certain groups,鈥� he says. Yet intelligence researchers are at pains to ensure that . 鈥淎nother, very common one was the idea that intelligence is difficult to measure.鈥�
The truth about intelligence: A guide for the confused
Our thinking on human intellect is clouded with misinformation. But the latest science of intelligence is surprisingly enlightening
No wonder IQ tests are often considered controversial and flaky. But that simply isn鈥檛 the case. 鈥淒espite the critiques, the intelligence test is one of the most reliable and solid behavioural tests ever invented,鈥� says Rex Jung at the University of New Mexico.
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That said, you shouldn鈥檛 trust the kind of 10-minute test that might pop up in your Facebook feed. A comprehensive IQ test takes well over an hour and is ideally administered by a professional examiner. It is designed to assess precisely those cognitive skills that constitute intelligence, so consists of a series of subtests that cover reasoning, vocabulary, mental processing speed, spatial ability and more. Shorter IQ tests, assessing fewer of these skills, can still provide a general indication of someone鈥檚 mental abilities, however, because the nature of intelligence means that someone who scores highly on one type of cognitive test will also do comparatively well on others.
However, an individual鈥檚 performance on an IQ test can be influenced by external factors such as motivation. And you can 鈥済ame鈥� the test by practising sample questions beforehand 鈥� although the average gain from such tutoring is just four or five points.
Is IQ up to the job?
Aside from questions over how robust the tests are, particular applications of IQ tests have also faced scrutiny. A common criticism of using them to screen job applicants is that they only measure a subset of cognitive skills. They don鈥檛 expressly measure creativity, for instance. Neither do they measure personality traits such as conscientiousness 鈥� which tends to make for reliable and hard-working employees 鈥� or ability to get on with other people. However, it is rare for recruiters to test IQ in isolation: candidates might be given a personality test too and a practical exercise to assess job-related skills. They usually also have to name several referees.
This article appeared in print under the headline 鈥淐an intelligence really be measured?鈥�
