Question
Is IQ related to memory?
Short answer
Yes, especially working memory, the ability to hold and use information for a few seconds. A meta-analysis of 86 samples found a correlation of about 0.48 between working memory and general intelligence, and a reanalysis focused on reasoning found about 0.72. They are closely related but not the same thing.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Which kind of memory matters
When researchers link memory and intelligence, they usually mean working memory: holding a few pieces of information in mind and doing something with them, such as keeping three rules in your head while you check the answer choices in a matrix puzzle. Its capacity is small. Nelson Cowan brought together evidence for a central limit averaging about four chunks (Cowan, 2001). See what working memory is for the full picture.
How strong the link is
Two analyses published side by side in 2005 give a range. Ackerman, Beier and Boyle pooled 86 samples and found an average true-score correlation of about 0.48 between working memory and general intelligence, which they called substantially less than unity (Ackerman et al., 2005). Kane, Hambrick and Conway reanalyzed 14 data sets with more than 3,100 young adults and found a median correlation of 0.72 between working memory capacity and fluid reasoning, about 50% shared variance (Kane et al., 2005).
Both teams agreed on the key point: working memory is not the same thing as intelligence (Kane et al., 2005). They disagreed on how close the two are, partly because they measured reasoning in different ways.
Try one · Pattern Recognition
Which tile comes next?
Tap the option you think is right, or show the answer.
Show the answer
The missing tile shows a very large hatched arrow pointing right (option 3).
How to solve it
- Compare neighboring tiles and name what changes each time.
- From tile to tile, the arrow turns a quarter turn clockwise.
- The fill cycles hatched, solid and outline, then starts again.
- Everything else stays the same from tile to tile.
- The last tile shows a very large outlined arrow pointing up. Apply each change once more.
- So the missing tile shows a very large hatched arrow pointing right.
That was 1 puzzle. The full test has 25.
Why the two travel together
Reasoning problems make you juggle. In a number series you track several differences at once; in a matrix you compare rows while remembering which rules you have ruled out. A larger or better-controlled workspace makes that juggling easier, which is one plausible reason working memory and reasoning scores rise and fall together across people.
What this means for you
- A strong memory for facts is not the same as a high reasoning score, and the reverse holds too.
- On puzzles, writing nothing down is part of the challenge. Working through rules one at a time, as the matrix reasoning guide shows, eases the load on working memory.
- Training working memory with apps has a weak record for raising intelligence; see can you raise your intelligence.
Sources
- Ackerman, P. L., Beier, M. E., & Boyle, M. O. (2005). Working memory and intelligence: The same or different constructs? Psychological Bulletin, 131(1), 30-60. doi.org/10.1037/0033-2909.131.1.30
- Kane, M. J., Hambrick, D. Z., & Conway, A. R. A. (2005). Working memory capacity and fluid intelligence are strongly related constructs: Comment on Ackerman, Beier, and Boyle (2005). Psychological Bulletin, 131(1), 66-71. doi.org/10.1037/0033-2909.131.1.66
- Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24(1), 87-114. doi.org/10.1017/S0140525X01003922