The idea that intelligence can be captured in one number is very misleading, psychologists have argued.
Many thousands used 12 different cognitive tests in a recent study.
People’s reasoning, attention, planning, lifestyles and backgrounds were probed.
Professor Adrian M. Owen, one of the study’s authors, said:
“The uptake was astonishing.
We expected a few hundred responses, but thousands and thousands of people took part, including people of all ages, cultures and creeds from every corner of the world.”
People’s thinking skills could not be successfully described with one number, the researchers found.
Instead they found at least three components of intelligence:
- Short-term memory.
- Verbal ability.
Brains scans showed that distinct abilities mapped on to specific circuits in the brain.
The researchers also discovered some factors which did and did not affect intelligence.
Professor Owen said:
“Regular brain training didn’t help people’s cognitive performance at all yet aging had a profound negative effect on both memory and reasoning abilities.”
Not all the news was bad, though, said Dr Adam Hampshire, the study’s first author:
“Intriguingly, people who regularly played computer games did perform significantly better in terms of both reasoning and short-term memory.
And smokers performed poorly on the short-term memory and the verbal factors, while people who frequently suffer from anxiety performed badly on the short-term memory factor in particular.”
Despite being so popular, intelligence tests have faced a barrage of criticism since their inception.
One problem is that IQ tests don’t take culture into account.
A recent study, for example, gave IQ tests to Morroccan and Spanish people (Fasfous et al., 2013).
This showed that the results depended on where people came from.
Most psychologists would agree, though, that people whose cognitive skills are better in one area are also generally better in others.
Purely academic arguments aside, though, the real question is: what are IQ tests being used for?
If they are used as one of a number of indicators of a person’s abilities, then perhaps they can be useful.
If a single number comes to stand for a person’s whole worth, though, then that is a very serious mistake.
The study was published in the journal Neuron (Hampshire et al., 2012).
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
IQ test image from Shutterstock