Can mental training improve your intelligence? No video game or mental puzzle has convincingly been shown to work. But now a group of neuropsychologists claims it has found a task that can add points to a person’s IQ – and the harder you train, they say, the more you gain.

So-called “fluid intelligence”, or Gf, is the ability to reason, solve new problems and think in the abstract. It correlates with professional and educational success and it appears to be largely genetic.

Past attempts to boost Gf have suggested that, although by training you can achieve great gains on the specific training task itself, those gains don’t transfer to other tasks.

Now Susanne Jaeggi at the University of Michigan at Ann Arbor, US, and her colleagues say that is not true.


They invited 70 healthy adults to participate in a challenging training exercise known as the “dual n-back” task.

Daily training

The exercise involves tracking small squares on a screen that pop into a new location every three seconds. Volunteers have to press a button when the current location is a duplicate of two views earlier.

At the same time, consonants are played through headphones and a button is pressed if the letter is the same as that heard two “plays” earlier.

If participants perform well, the interval to be tracked (n) increases to three or more stages earlier.

Jaeggi’s volunteers were trained daily for about 20 minutes for either 8, 12, 17 or 19 days (with weekends off). They were given IQ tests both before and after the training.

The researchers found that the IQ of trained individuals increased significantly more than controls – and that the more training people got, the higher the score.

Small study

“It definitely challenges the old opinions,” says Jaeggi. She thinks their training regimen succeeded where others failed largely because it remained challenging. Also, because it was tailor-made to the individual, people were never able to go on autopilot.

Not everyone is impressed. Robert Plomin, at the Institute of Psychiatry in London, says that no serious intelligence researchers consider Gf “immutable”, as the paper suggests.

“There is no contradiction at all between substantial heritability and improvement of performance,” he says. “What is school about?”

Plomin says what is more interesting is how much an individual can profit from training. He complains, however, that the researchers did not really address this in the research, and that the study, with nine subjects in each of four training conditions, is much too small to detect it.

Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0801268105)