Question
Does reading make you smarter?
Short answer
There is good evidence that learning to read well helps. In a study of 1,890 pairs of identical twins tested from age 7 to 16, the twin who read better earlier tended to score higher on intelligence tests later, including nonverbal tests. Because identical twins share their genes, genetics cannot explain that difference.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Why twins make this question answerable
Children who read well also tend to do well on IQ tests, but that link alone could mean many things. Brighter children might just learn to read sooner, or the same family advantages might help both. Identical twins offer a cleaner test. They share all their genes and grow up in the same home, so if one twin reads better than the other and later pulls ahead on reasoning, genes and family background cannot be the reason.
What the study found
Stuart Ritchie, Timothy Bates and Robert Plomin followed 1,890 pairs of identical twins tested at ages 7, 9, 10, 12 and 16. They looked at whether differences in reading ability within a pair at one age predicted differences in intelligence at a later age. They found several such associations. The links were not explained by how much the twins were exposed to reading, and they were not restricted to verbal abilities (Ritchie, Bates & Plomin, 2015).
In plain terms: getting better at reading seems to feed into broader reasoning, including the nonverbal kind that matrix and pattern puzzles test. The authors were careful to say the mechanism is still an open question.
Try one · Abstract Reasoning
Which tile completes the grid?
Tap the option you think is right, or show the answer.
Show the answer
The missing tile has three solid diamonds (option 4).
How to solve it
- Start with the first row and name what changes from tile to tile.
- Every row and every column contains each shape (diamond, circle and square) exactly once.
- Every row and every column contains each number of shapes (two, three and one) exactly once.
- The fill (solid) stays the same in every tile.
- Check the rules on the second row, then apply them to the third.
- So the missing tile has three solid diamonds.
That was 1 puzzle. The full test has 25.
How it fits with what else we know
The heritability of intelligence rises with age, to perhaps 80% in later adulthood (Plomin & Deary, 2015), yet that still leaves room for experience. Schooling is the best-documented example: a 2018 meta-analysis of over 600,000 people found each extra year of education raises IQ by about 1 to 5 points (Ritchie & Tucker-Drob, 2018). Reading is a plausible part of why. See does education increase IQ and genes and intelligence.
What we cannot tell you
The study was about children learning to read, measured by reading ability. It does not tell us how many points a particular book habit adds for an adult, and we will not guess. If you want to know where your reasoning stands now, the free practice tests are a quick start, and can you raise your intelligence covers what else the evidence supports.
Sources
- Ritchie, S. J., Bates, T. C., & Plomin, R. (2015). Does learning to read improve intelligence? Child Development, 86(1), 23-36. doi.org/10.1111/cdev.12272
- Ritchie, S. J., & Tucker-Drob, E. M. (2018). How much does education improve intelligence? A meta-analysis. Psychological Science, 29(8), 1358-1369. doi.org/10.1177/0956797618774253
- Plomin, R., & Deary, I. J. (2015). Molecular Psychiatry, 20, 98-108. doi.org/10.1038/mp.2014.105