For many years now we have all been agonising over the fertility crisis. Why aren’t the kids having kids? It’s become a sort of parlour game, the swapping of the various theories. Is it the cost of living? Micro-plastics? Eco-anxiety? Tight underwear, I heard the other day, and snorted with scorn even as I tipped my son’s stretch-cotton pants into the bin. But now another, rather more fundamental explanation for the baby shortage has emerged. It’s not just that younger generations aren’t having babies – it turns out they aren’t really having sex at all. The Atlantic was first to...