Is working memory related to IQ?
Working memory and fluid IQ (the ability to solve novel problems) correlate strongly — typically r ≈ 0.5–0.6 in meta-analyses. This is one of the highest correlations between any cognitive test and general intelligence.
The relationship is not simply that smart people have better memory — it is that working memory capacity is a core component of fluid intelligence. It limits how many variables you can hold in mind simultaneously when solving a problem, which directly constrains reasoning complexity.
| WM predicts | Correlation (r) | Strength |
|---|---|---|
| Fluid intelligence (IQ) | 0.50–0.60 | Strong |
| Academic achievement | 0.45–0.55 | Strong |
| Reading comprehension | 0.40–0.50 | Moderate-strong |
| Mathematical ability | 0.45–0.55 | Strong |
| Long-term learning rate | 0.35–0.45 | Moderate |
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Quick Answer
Working memory and fluid IQ correlate strongly (r ≈ 0.5–0.6). It predicts academic performance, reading comprehension, and problem-solving ability better than many other cognitive measures.
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