This research study looked at 1,890 identical twin pairs, it appears that developing reading comprehension skills can enhance IQ. Prior research has demonstrated that both genes and environment impact a person’s IQ. Studies of identical twins, who share virtually 100% of the same genes (as opposed to fraternal twins or siblings who share 50% of the same genes) indicate that twins in the same family environment can have different IQ levels.
This is strong evidence that IQ is not solely related to genetics, and is impacted by environmental factors. How environmental factors might affect IQ was a focus of this study. The researchers examined reading ability and comprehension in twin pairs, and found that the twin who tested higher in reading skills tended to test higher in IQ. The study looked at children aged 7-16, and did not examine reading skills for very young children. Presumably, parents can benefit their children by promoting good reading habits early, which involve not only an interest in stories but an ability pull meanings out stories.
Ritchie, Stuart, Timothy Bates, and Robert Plomin. “Does Learning to Read Improve Intelligence? A Longitudinal Multivariate Analysis in Identical Twins From Age 7 to 16.” Child Development 86 (1) (2015).