The study, published in the journal Pediatrics, followed 1,000 children between the ages of 5 and 15. Every two years their TV viewing habits were sampled. Those who watched more TV were also more likely to have a criminal conviction in adulthood and more likely "to have antisocial personality traits." Every extra hour spent watching TV on an average weeknight corresponded with an estimated 30% increase of having a criminal conviction in adulthood.
"Antisocial behavior is a major problem for society," said Bob Hancox, associate professor in the department of prevantive and social medicine at the University of Otago. "While we're not saying that television causes all antisocial behaviour, our findings do suggest that reducing TV viewing could go some way towards reducing rates of antisocial behavior in society."
Children who viewed more TV were also found to have "aggressive personality traits, an increased tendency to experience negative emotions, and an increased risk of antisocial personality disorder" as adults.
Though it was not able to prove that TV viewing caused personality problems, the study was able to rule out the idea that children who are more antisocial simply gravitated to watching more TV.
"Rather, children who watched a lot of television were likely to go on to manifest antisocial behaviour and personality traits," said Lindsay Robertson, co-author of the study.