Does N-back training raise your IQ?

The study that started it all

In 2008, researchers Jaeggi, Buschkuehl, Jonides and Perrig published a paper with a startling claim: training on a dual N-back task improved participants' fluid intelligence — the ability to reason and solve novel problems, long thought to be largely fixed. Even better, the effect seemed dose-dependent: more training, bigger gains. The internet, predictably, lost its mind. Dual N-back became the nootropic of choice for people who wanted to "level up" their brains.

Then came the replications

This is where the story gets responsible but less thrilling. When other labs tried to reproduce the result, things fell apart. Redick and colleagues (2013), running a careful version with a proper active control group, found no transfer to fluid intelligence at all. Critics pointed to small sample sizes, weak control groups, and a pattern where improvements showed up on tests similar to the training but vanished on genuinely independent measures. Meta-analyses that pooled many studies concluded the far-transfer effect was, at best, tiny — and possibly an artefact of how the studies were designed.

What we can safely say

Stripping away the hype, here's what survives scrutiny:

• N-back training improves N-back performance. Reliably and substantially. This is real (near transfer).
• It may improve closely related working-memory tasks. The evidence is mixed but not nothing.
• It probably does not raise general intelligence. The strong far-transfer claim has not held up to repeated testing. Anyone selling you N-back as an IQ booster is getting ahead of the evidence.

So is N-back a waste of time?

Not at all — as long as you play it for the right reasons. N-back is a genuinely demanding test of working-memory updating: holding recent information in mind, comparing it, and refreshing it as new items arrive. It's humbling, it's absorbing, and getting better at it feels great. Those are honest reasons to play. "It'll make you smarter" is not one we'll offer you.

Try it for yourself

Our N-back game runs a 2-back challenge in about a minute and scores both your hits and your restraint (false alarms count against you). It's free, needs no account, and makes no promises beyond a properly hard mental workout. Want the hands-on version? Read our full N-Back review.