Studies have identified concurrent, longitudinal, and bidirectional associations between language difficulties and internalizing problems. This is commonly explained by social exclusion or withdrawal from peers, but underlying mechanisms are not well understood. This study uses sibling data to investigate if the comorbidity between language difficulties and internalizing problems is best explained by familial factors shared by siblings, such as genes or family environment, or nonfamilial factors specific to each child, such as peer environment. Data include 5,568 siblings at 5 years and 3,654 siblings at 8 years participating in the Norwegian Mother, Father and Child Cohort Study (MoBa). We constructed a latent factor model at 5 and 8 years, including a family comorbidity factor capturing correlations between language and internalizing problems that were equally strong between as within siblings. Results showed that the correlation between one sibling’s internalizing problems and the other sibling’s language problems was mostly accounted for by a family comorbidity factor. The best-fitting longitudinal model included stability of the family comorbidity factor and stability of language and internalizing problems within each sibling and no cross-sibling or cross-trait longitudinal associations. This suggests that the association between language and internalizing problems may be best explained by family factors.

中文翻译：

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导致语言困难和内化问题的共同家庭因素：基于人口的兄弟姐妹研究的结果

研究已经确定了语言困难和内化问题之间的并发、纵向和双向关联。这通常可以通过社会排斥或从同龄人中退出来解释，但潜在的机制尚不清楚。本研究使用兄弟姐妹数据来调查语言困难和内化问题之间的共病是否可以用兄弟姐妹共有的家族因素（例如基因或家庭环境）或每个孩子特有的非家族因素（例如同伴环境）来最好地解释。数据包括参与挪威母亲、父亲和儿童队列研究 (MoBa) 的 5,568 名兄弟姐妹和 8 岁的 3,654 名兄弟姐妹。我们构建了一个 5 年和 8 年的潜在因子模型，包括一个家庭合并症因素，它捕捉语言和内化问题之间的相关性，这些相关性在兄弟姐妹之间同样强烈。结果表明，一个兄弟姐妹的内化问题与另一个兄弟姐妹的语言问题之间的相关性主要是由家庭合并症因素引起的。最合适的纵向模型包括家庭合并症因素的稳定性以及每个兄弟姐妹内语言和内化问题的稳定性，并且没有跨兄弟姐妹或跨特质的纵向关联。这表明语言和内化问题之间的关联可能最好用家庭因素来解释。结果表明，一个兄弟姐妹的内化问题与另一个兄弟姐妹的语言问题之间的相关性主要是由家庭合并症因素引起的。最合适的纵向模型包括家庭合并症因素的稳定性以及每个兄弟姐妹内语言和内化问题的稳定性，并且没有跨兄弟姐妹或跨特质的纵向关联。这表明语言和内化问题之间的关联可能最好用家庭因素来解释。结果表明，一个兄弟姐妹的内化问题与另一个兄弟姐妹的语言问题之间的相关性主要是由家庭合并症因素引起的。最合适的纵向模型包括家庭合并症因素的稳定性以及每个兄弟姐妹内语言和内化问题的稳定性，并且没有跨兄弟姐妹或跨特质的纵向关联。这表明语言和内化问题之间的关联可能最好用家庭因素来解释。