Though there’s still no definitive link between watching TV and an increase of violence, there may be one between TV-watching and puberty. “Girls are reaching puberty much earlier than in the 1950s. One reason is due to their average increase in weight; but another may be due to reduced levels of melatonin. Scientists at the University of Florence in Italy found that when youngsters were deprived of their TV sets, computers and video games, their melatonin production increased by an average 30 per cent.