Genetic and environmental Influences on screen-time behaviors among adolescents

In a paper with Dr.Niels van der Aa as first author, just published online by Arcives of Pediatric and Adolescent Medicine, we report on an investigation of the genetic and environmental influences on sedentary behavior, i.e. TV and computer time, among adolescents. The paper is based on analyes of cross sectional data from the Netherlands Twin Registrer. The Netherlands Twin Register (NTR) was established in 1987 at the Vrije Universiteit in Amsterdam for scientific research purposes. The study of twins and their family members can provide insight into what extent the causes of differences between individuals are determined by genetic and environmental influences. Prof. Dorret Boomsma, (or see her EMGO personal page) co-author of the paper, is the founder of this registry.

The study published in Archives shows that differences in sedentary behavior can to a large extend be explained by genetic factors, and that the importance of genetic influence increases from age 12 to age 20. To be a bit more specific, our data showed that variation in adolescent sedentary behavior was largely accounted for by genetic and nonshared environmental factors, whereas shared environmental factors account for a substantial part of the variation among younger adolescents. The shift from shared environmental factors in the etiology of sedentary behavior among younger adolescents to genetic and nonshared environmental factors among older adolescents has consequences for intervention programs that aim to reduce adolescents' screen-tme behaviors. These require specific tailoring to age groups and need to focus on peers and parents in early adolescence but on the youngsters themselves at later ages.