Unravelling the link between reading ability and print exposure

Purpose What is the relation between how much children read for pleasure and how well they read? And why are they related at all? Do children who read a great deal become better readers, do good readers spent more and more... [ view full abstract ]

Purpose

What is the relation between how much children read for pleasure and how well they read? And why are they related at all? Do children who read a great deal become better readers, do good readers spent more and more time on reading, or is a third underlying variable at play?

Method

Partial data were available for a large sample of twin children (N = 11,408) and 389 siblings, all enrolled in the Netherlands Twin Register. Children were assessed around 7.5 years of age. Mothers completed questionnaires on children’s reading ability and time spent on reading activities. In addition, information on reading ability was available through teacher ratings and performance on national reading tests. For siblings only test results were available.

Results

Reading ability did not differ between twin and non-twin children, supporting that twin findings can be generalized to the population. For the twin sample, a measurement model was specified with two latent variables, Reading Ability and Print Exposure, which correlated .41. Heritability analyses showed that Reading Ability was highly heritable, while for Print Exposure genetic and environmental influences were equally important. We employed the fact that the two differed in genetic architecture and fitted direction of causality models (see Duffy & Martin, 1994). These models supported a causative relationship running from Reading Ability to Print Exposure.

Conclusion

How much and how well children read are moderately correlated. Individual differences in print exposure show stronger environmental influences than individual differences in reading ability. Importantly, it seems that children’s reading ability influences how much they choose to read, rather than vice versa.

(Reference: Duffy, D.L. & Martin, N.G. (1994). Inferring the direction of causation in cross-sectional twin data: Theoretical and empirical considerations. Genetic Epidemiology, 11(6), 483-502.)