Is there any point in IQ tests?

Just what is the point of an IQ test – should we bother with them and are they accurate? IQ or Intelligence Quotient is the standard measure of intelligence, and is considered to be stable throughout our lifetime – or so it was thought. Researchers from UCL have discovered that our IQ actually does change.

Recent research undertaken by Professor Cathy Price from the Wellcome Trust Centre for Neuroimaging at UCL has found that your IQ can change significantly during adolescence – meaning the IQ test you took as a child – if you took one – probably isn’t very meaningful.

Researchers tested the verbal IQ of 33 healthy children between the ages of 12 and 16 in 2004, and repeated the tests four years later. On both occasions, structural brain scans were taken using MRI. They found significant changes in IQ scores from 2008 compared to 2004 – some had improved by as many as 20 points on the standardised IQ scale, while others had dropped by similar amounts.

Upon analysing the brain scans, researchers found a clear correlation between the change in performance and changes in the structure of the brain. An increase in verbal IQ correlated with an increase in the density of grey matter in left of the motor cortex, while an increase in non-verbal IQ was associated with an increase in the density of grey matter in the anterior cerebellum. However, an increase in verbal IQ didn’t necessarily constitute an increase in non-verbal IQ.

Price in unsure why IQ should change so much, and why some people’s performance improved while others’ declined. She believes some of it may be due to participants being early or later developers, but it’s equally likely that education could have played a role – which could have important implications for how schoolchildren are assessed.

“We have a tendency to assess children and determine their course of education relatively early in life, but here we have shown that their intelligence is likely to be still developing,” said Price. “We have to be careful not to write off poorer performers at an early stage when in fact their IQ may improve significantly given a few more years.”

Price also believes a person’s IQ can change through their adult life, with the brain adapting and changing structure. So it begs the question – should we really bother with IQ tests? Modern IQ tests were developed in 19th Century France as a means of separating the mentally retarded from the mentally ill but today –in terms of predicting a child’s future – I fail to see its benefits.

IT could even be quite damaging – a child with a lower IQ might be deterred from following their desired career path because their IQ test suggests they might not be suited to it. Even worse, since their IQ changes over time, they might not be encourage to reach their full potential, because an IQ test taken years earlier suggests their potential is much lower. Alfred Binet – who developed the first IQ tests in France – warned against their use as a general ranking scale for all pupils according to mental worth.

He said: “The scale, properly speaking, does not permit the measure of intelligence, because intellectual qualities are not superimposable, and therefore cannot be measured as linear surfaces are measured.”

In other words, using IQ as a statement of a child’s intellectual capacity would be a mistake. He feared that the measurement would be used to condemn a child to a permanent condition of stupidity, negatively affecting their education and livelihood.

Worse still, the term intelligence hasn’t been adequately defined – so what does an IQ test really measure? Your ability to answer a few standardised puzzles? But just because you do well in those, doesn’t mean you’re going be successful. And just because your IQ is high, doesn’t mean you have life skills and will have a full rounded life.

So why is there so much emphasis on IQ – particularly in America, where certain public policies and laws regarding military service, education, public benefits, capital punishment and employment incorporate an individual’s IQ into their decisions? Indeed, prisoners on death row have been spared execution because of their low IQ.

However, in the UK they seem much less important – the only reason we seem to take them, particularly as adults, is for bragging rights.

Author Kerry Taylor Smith Web Editor, Laboratory News