Is it possibly because they're not sleeping with each other? Seems to be all over the news lately, the decline of young people having sex. The older I get, the less I see sex as optional for human health and well-being. There's no time you crave it more than adolescence, so going without it then could be even more damaging. Sex is not just a fun experience, it's a basic psychological need. Both the left and right in the US are way too puritanical and I really hope there's a big shift in popular culture to stop censoring sex and maybe think about toning down the violence.