It can be the subject of some heated debates, but what is the causal direction between reading ability and reading pleasure? A 2018 study Wouter Duyck shared on Twitter sheds some light on this and it seems that the better you’re able to read, the bigger chance that you will be enjoying reading.

The study by Elsje van Bergen and colleagues used data of 11,559 twins, born between 1994 and 2004, and 262 siblings. And what did they find?

We found evidence for a causal influence of reading ability on print exposure, consistent with previous findings from behavioural studies (Aarnoutse & van Leeuwe, 1998; Harlaar et al., 2011; Leppänen et al., 2005). Our findings refute the common belief that there is an influence of print exposure on reading ability, or that there are reciprocal influences between them.

But as always it’s a bit more complicated, but not in a way that it refutes these findings (bold by me):

The finding that reading ability is the driver of print exposure does not, of course, imply that exposure to print and thus exposure to orthographic forms is irrelevant to learning to read. To become a skilled reader, it is undoubtedly important to develop detailed lexical representations of words (Nation, 2017; Perfetti, 2007). However, while this may take as little as a single exposure in some readers (Tamura, Castles, & Nation, 2017), in poor readers, it takes much longer to consolidate new learning (Share & Shalev, 2004). Moreover, although a fair assumption is that schools provide the necessary practice, measures of print exposure on which good and poor readers differ, tap reading outside of school hours. We demonstrate here that whether children choose to read for themselves depends, in part, on their reading ability, underlining the fact that poor readers choose to read less. In fact, we found that reading ability accounted for 16% of the variance in print exposure. In addition, other influences, both genetic and shared environmental, are also at play.

Abstract of the study:

Background
This study investigates the causal relationships between reading and print exposure and investigates whether the amount children read outside school determines how well they read, or vice versa. Previous findings from behavioural studies suggest that reading predicts print exposure. Here, we use twin‐data and apply the behaviour‐genetic approach of direction of causality modelling, suggested by Heath et al. (1993), to investigate the causal relationships between these two traits.

Method
Partial data were available for a large sample of twin children (N = 11,559) and 262 siblings, all enrolled in the Netherlands Twin Register. Children were assessed around 7.5 years of age. Mothers completed questionnaires reporting children’s time spent on reading activities and reading ability. Additional information on reading ability was available through teacher ratings and performance on national reading tests. For siblings reading test, results were available.

Results
The reading ability of the twins was comparable to that of the siblings and national norms, showing that twin findings can be generalized to the population. 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 genetic and environmental influences were equally important for Print Exposure. We exploited the fact that the two constructs differ in genetic architecture and fitted direction of causality models. The results supported a causal relationship running from Reading Ability to Print Exposure.

Conclusions
How much and how well children read are moderately correlated. Individual differences in print exposure are less heritable than individual differences in reading ability. Importantly, the present results suggest that it is the children’s reading ability that determines how much they choose to read, rather than vice versa.