Genes determine how young people use internet and social media

Genes play an unexpectedly big role in determining how young people use the internet and social media, according to a large UK study of 16-year-olds.

More than one-third of differences between individuals’ online behaviour — for example, how much time they spend playing games or in chat rooms — can be attributed to genetics rather than environmental factors such as family circumstances and availability of computers and smartphones, the Financial Times reports.

The researchers at King’s College London said the study, published in the journal PLoS One, challenges a common belief that people are passive or helpless consumers of media. “Our results support an active model of the environment, where young people choose their online engagements in line with their genetic propensities,” said Ziada Ayorech, first author. “Finding that DNA differences substantially influence how individuals interact with the media puts the consumer in the driver’s seat, selecting and modifying their media exposure according to their needs.” The study analysed online media use in 8,500 teenage twins. By comparing identical twins who share all their DNA with non-identical ones who share half, the scientists estimated the relative contribution of genes and environment to individual differences in engagement with online media, from education to games and Facebook.

The results are expressed as “heritability” scores that show the percentage of differences between individuals that can be attributed to inherited genetic factors rather than environmental effects.

Heritability was 39 per cent for online gaming, 37 per cent for entertainment sites, 34 per cent for education and 24 per cent for social networking. “Although you would expect some genetic influence on online media use, as for any psychological trait, these are large effects — much larger than the sex differences between media use in girls and boys,” said Ms Ayorech.