Is it possible to change my IQ?

Imagine a safe deposit box in which you deposited 120 euros at the age of twelve. Four years later you want to withdraw the money - and only find 100 euros. What would you doubt: the bank, the safe or your way of counting?

Our brain works in a similar way to a leaky bank safe. At least that is what a study recently published in the journal “Nature” suggests. Our intelligence quotient (IQ) is therefore not an immutable value, but something that can change rapidly within a few years - for better or for worse. Brain researchers led by Sue Ramsden from University College in London had 32 students between the ages of 12 and 16 each take an intelligence test for their study and then examined the teenagers' brains using magnetic resonance imaging. The scientists repeated the same thing four years later. The IQ test tested two forms of intelligence - verbal and practical. For the verbal IQ, for example, linguistic ability and general knowledge are tested, the practical shows how well someone can solve puzzles, for example. Together they make up the total IQ. As is usual with intelligence tests, the result is offset against age.

The result of the London tests not only surprised experts: the intelligence values ​​of many test subjects fluctuated extremely between the two measurements. And the brain structures also changed significantly in some cases. The verbal intelligence quotient changed in every fifth person, and 40 percent had new values ​​for practical IQ. In the extreme, one teenager's overall IQ decreased by 20 points and that of another increased by 23 points. "We found a clear connection between these changes in performance and changes in the structure of the brain," says Sue Ramsden. "So we can say with some certainty that these changes in IQ are real."

The researchers do not yet know why the intelligence values ​​of adolescents changed in such a way within a few years. Why the value rose for some, while it fell sharply for others, is unclear, admits study director Ramsden. It is possible that the results simply reflect natural differences in development. It is also conceivable that education plays a role. That would mean, however, that intelligence, like physical fitness, can be "trained". “This level of plasticity could perhaps persist throughout life,” believes Ramsden. If the effect - which follow-up studies are supposed to show - can also be demonstrated in adults, that would be a minor sensation. After all, the intelligence quotient would then only be an indicator with a limited shelf life.

Gifted club cafeteria skeptical

What does a test completed four years ago say about a person's current cognitive performance? How sensible would it be to make IQ scores a criterion for gifted children in children? According to an educational brochure from the Federal Ministry of Family Affairs, an IQ test is only reliable "if it leads to the same results for the same person over several measurements". How do high deviations fit into the picture?

"We are very critical of the results of the British study," says Matthias Moehl, chairman of the highly gifted Mensa association in Germany. "Our experience is that a person's intelligence is relatively stable over their lifetime." The negative attitude of the cafeteria spokesman is not surprising: Members of the cafeteria can only be those who can show an IQ over 130, determined in a classic IQ- Test. The 44-year-old says the test is only done once when recording. Hardly any member can be tested a second time.

At the same time, cafeteria boss Moehl knows that IQ tests are not always the same. Factors such as nervousness and daily form can greatly distort the results, admits Moehl: "It's like the 100-meter run, you are not equally fast every day." However, this tolerance range, which is provided for by the IQ test from Mensa , only at seven points. The test is based on a procedure for which 30,000 testers were used. He could not take a study with only 32 participants very seriously, although the result of the brain researchers is only the latest argument in the more than hundred-year history of criticism of the intelligence test. The neurologist Alfred Binet, the pioneer of IQ research, expressed doubts about his own method. He had been the first to try to test children's aptitude for school in the 1890s. But he remained skeptical: "To be honest, the scale does not allow a measurement of intelligence," he said.

Nevertheless, the new method spread rapidly. The dazzling variety of meanings of the term intelligence, which the ancient Greeks used to mean “temperament” and sometimes “reflection”, was forgotten. The Doctors of the Church in the Middle Ages, for whom intelligence was an attribute of God, were also forgotten. Modernity brought the term down to earth in order to immediately put it on a pedestal. For the psychologist Hans Jürgen Eysenck, author of the bestseller “The IQ Bible”, he was the key to happiness: “The IQ test predicts school and academic performance precisely.” It's just stupid that, according to Eysenck, you can hardly tell from your stupidity can change something: "It has been known for a long time that IQ differences are caused to a far greater extent by genetic makeup than by environmental factors."

Different test categories

Such blanket theses are now considered obsolete. “There is no uniform definition of intelligence,” explains Jutta Stahl, Professor of Differential Psychology at the University of Cologne. "If I believe that logical thinking means intelligence, I have to measure differently than when I examine verbal thinking." Modern tests - including the London test - combine questions from different categories. How much the individual areas - linguistic, mathematical, social - are included in the overall rating is different in each test.

Nevertheless, IQ tests are still carried out at the Cologne institute, explains Stahl, for example in career counseling: “You can see, for example, whether someone is suitable for a mathematical profession.” However, you do not give a numerical value. “We only give three categories: above average, average and below average.” Stahl considers an overall IQ as an average value to be “scientifically problematic”.

Be careful when evaluating children

According to Sue Ramsden, the London results are of great importance for assessing the performance of children and young people. "We have a tendency to determine the further educational path of children relatively early in life," says the neuroscientist. Now it has been shown that the intelligence of children is developing even further. "We should therefore be careful about writing off supposedly underperformers early on," warns the researcher. After all, her IQ could have improved significantly just a few years later.

Perhaps the smartest thing to say about measuring intelligence is a phrase from Stephen Jay Gould. In his book "The Wrongly Measured Man", the evolution researcher and anthropologist writes: "Intelligence is what is measured in an intelligence test."