Working memory training won’t make you more intelligent

Some studies have suggested that training working memory is effective. This has led to it becoming the most popular form of intelligence-training intervention, write the authors of new paper in the Journal of Experimental Psychology: Learning, Memory and Cognition.

There have been mixed results in this area though, and, the team argues, potential problems with the methodology of some previous studies, making it hard to draw firm conclusions. (For example, some of the trials that failed to find an effect perhaps involved too little training.) So they set out to run as definitive a trial as possible. The results of their two-year longitudinal study now suggest that while working memory can indeed be improved in typically developing children, this has no impact whatsoever on intelligence.

Working memory is the type that you use to consciously hold and manipulate information in your mind. No end of studies have linked better working memory scores to greater "fluid intelligence" — the sort involved in reasoning and learning. (Fluid intelligence is widely viewed as the "key ingredient" in human cognitive abilities, the team notes.) In fact, working memory has been viewed as the underpinning of fluid intelligence for decades. So it's certainly reasonable to think that improving someone's working memory might improve their intelligence, too.

The team studied 225 healthy German children, who were aged about 14 when the study began. All had their working memory and intelligence assessed at the start and end of the two-year period. To measure working memory, the team used three types of tasks, which involved letters, numbers and spatial positions (alpha span, memory updating and N-back). All required the participants to hold and manipulate chunks of information in their mind to do well.

About half of the children were in the intervention group. Every two weeks, they spent an hour engaged in versions of these three working memory tasks. In total, they received 40 hours of training over the study period.

The results showed that this extensive practice did indeed boost their performance on these tasks. Two years on, these children had got better at all three — and they did substantially better than the control group. Also, the team's analysis suggested that the trained children experienced a more general improvement in working memory that wasn't only restricted to the individual tasks. However, they write, "Despite the striking improvements in WM [working memory], we did not observe transfer to intelligence."

Given all the data clearly linking working memory and intelligence, this prompts the question: why not?

There is no clear answer to that. Despite the apparent usefulness of a good working memory for reasoning and learning, perhaps something else underpins both working memory capacity and fluid intelligence, and it's that underlying X factor that explains the link between the two.

There are some recent meta-analyses that also cast doubt on the idea that working memory training improves intelligence, the team notes. And in fact, of all the brain-training interventions that have been explored, only one has been found to consistently and robustly improve intelligence. That, as they write, is education — a "dosage" of several hours a day of broad brain training for most weeks of the year, over many years.

Perhaps future work will find that a briefer intervention does reliably improve intelligence. And there's no doubt that work in this field will continue. "Because the consequence of successful interventions would be far-reaching, research into (alternative) cognitive interventions will persist," the team concludes. For now, though, it seems that if your goal is to become smarter, working memory training is a waste of time. 

Further reading

– Training working memory for two years—No evidence of transfer to intelligence.

About the author

Emma Young (@EmmaELYoung) is a staff writer at BPS Research Digest