A new study suggests that a person's intelligence quotient can change during his or her teenage years, and those fluctuations are related to physical changes in the structure of the brain. Scientists have been arguing for years over whether a person’s IQ is fixed. Is there a proven way to increase your IQ score?
Yes, but increasing actual intelligence is much more difficult. There’s a really easy way to improve your performance on IQ tests: Take lots of them. Researchers call this the “practice effect,” and it’s pretty foolproof. But there’s a catch. IQ tests are intended to measure something known in the field of psychometrics as g, or general intelligence. The link between IQ tests and the fabled g has been established through decades of longitudinal studies showing that those who do well on IQ tests get better grades, perform better on the SATs, and make more money. The problem with improving your IQ scores by taking the test over and over is that the practice effect breaks the correlation between IQ and g. Practicing only makes you better at the test; it doesn’t make you smarter.
The best known method to improve underlying intelligence is hard work. Teenage dropouts lose between 1.5 and 5 points of IQ for every year of school they miss. People who work in challenging jobs that require problem-solving skills see gradual increases in their IQ scores, while those whose jobs involve mindless repetition see their test scores erode over time. The elderly are at special risk for mental atrophy and declining IQ. It’s difficult to link these IQ differences to changes in g, for a variety of reasons. For example, high school dropouts have less success in life, but it’s not clear whether that’s because of declining general intelligence or because they don’t have a diploma. The problem of how to separate out achievement from aptitude bedevils psychometric research.
Is there a quicker way to get smart? Maybe. In 2008, researchers at the University of Michigan and the University of Bern conducted a study in which participants repeatedly played a memory game. Every three seconds, a computer screen displayed a visual pattern. Each time a new pattern appeared, the participant also heard a letter of the alphabet in her headphones. The task was to respond when either a visual pattern or a letter was repeated at some specified delay. As the participants got better at the game, they were asked to identify repeated letters and patterns that were further and further apart in the sequence. The researchers found that their subjects’ scores on IQ-style tests increased as their proficiency at the memory game improved.
It’s not clear why the memory game improves IQ scores, but the study’s authors speculated that it taught participants how to juggle multiple ideas in their heads simultaneously—a useful skill when trying to reason through an IQ exam question. There are still some open questions, though. It’s not yet known whether the skills learned in the memory game are useful in the real world, i.e., whether they increase your g. It’s also unclear whether the skills a person learns in the memory game stick with them. A follow-up study on children suggested that those who showed gains from the practice sessions maintained their skills, but children are somewhat better at picking up new skills than adults. It’s also important to remember that the memory game only improves one aspect of intelligence, albeit an apparently useful one.
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Explainer thanks Stephen Ceci of Cornell University and author of On Intelligence … More or Less: A Biological Treatise on Intellectual Development, John D. E. Gabrieli of MIT, Robert Sternberg of Oklahoma State University, and Sherry Willis of the University of Washington.