Childhood verbal development and drinking behaviors from adolescence to young adulthood: a discordant twin-pair analysis.

backgroundStudies suggest that better cognitive and verbal abilities in childhood predict earlier experimentation with alcohol and higher levels of drinking in adolescence, whereas poorer ability is related to a higher likelihood of remaining abstinent. Whether individual differences in language development in childhood predict differences in adolescent drinking behaviors has not been studied.

methodsTo address that question, we compared co-twins from twin pairs discordant for their childhood language development and studied associations of parental reports of within-pair differences in age at speaking words, age at learning to read, and expressive language skills during school age with self-reported within-pair differences in drinking, intoxication, and alcohol-related problems across adolescence and young adulthood. Data from 2 longitudinal population-based samples of twin families were used, with verbal developmental differences in childhood reported by the parents when the twins were 12 and 16 years of age, respectively.

resultsConditional logistic regression analyses and within-pair correlation analyses suggested positive associations between verbal development and drinking behaviors in both data sets. In analyses adjusted for birth order and birth weight, the co-twin reported to be verbally more advanced in childhood tended to report more frequent drinking and intoxication in adolescence in both samples. Better verbal development also was associated with the likelihood of having friends who drink in adolescence.

conclusionsThese findings suggest that, adjusting for familial and other factors shared by co-twins, better verbal development in childhood predicts more frequent drinking and intoxication in adolescence and young adulthood, possibly due, in part, to peer associations.