Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Experimental Psychology, University of Oxford, Oxford, UK.
J Child Psychol Psychiatry. 2018 Nov;59(11):1205-1214. doi: 10.1111/jcpp.12910. Epub 2018 Apr 10.
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. (), to investigate the causal relationships between these two traits.
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.
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.
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.
本研究旨在探讨阅读和印刷品接触之间的因果关系，并调查儿童在校外阅读的数量是否决定了他们的阅读水平，或者反之亦然。先前的行为研究结果表明，阅读可以预测印刷品的接触。在这里，我们使用双胞胎数据，并应用 Heath 等人（）提出的因果关系建模的行为遗传学方法，来研究这两个特征之间的因果关系。
一项针对大量双胞胎儿童（N=11559）和 262 对兄弟姐妹的大型双胞胎登记处的部分数据可用。儿童在 7.5 岁左右接受评估。母亲填写问卷，报告孩子的阅读活动时间和阅读能力。通过教师评价和全国阅读测试成绩，可以获得有关阅读能力的更多信息。对于兄弟姐妹的阅读测试，结果是可用的。
双胞胎的阅读能力与兄弟姐妹和全国平均水平相当，表明双胞胎的发现可以推广到人群中。指定了一个具有两个潜在变量的测量模型，即阅读能力和印刷品接触，它们的相关性为.41。遗传分析表明，阅读能力具有高度的遗传性，而遗传和环境因素对印刷品接触的影响同样重要。我们利用了这两个结构在遗传结构上的差异，并拟合了因果关系模型。结果支持从阅读能力到印刷品接触的因果关系。
儿童的阅读量和阅读水平有中度的相关性。印刷品接触的个体差异比阅读能力的个体差异遗传程度低。重要的是，本研究结果表明，是儿童的阅读能力决定了他们选择阅读的多少，而不是反之亦然。
