Prof Andy Phippe, at Plymouth University, who researches teenagers and their lives on social networks, says that courtship rituals (“though they would never call it that”) often start with a boy asking a girl to send a selfie, before asking for more explicit pictures. “There are hundreds of thousands of selfies taken every day which do no harm. It’s when it breaks from the sphere of trust that I would be concerned.” The need for teens to seek affirmation is as old as adolescence itself. “But what is new is the avenues through which their contemporaries can either say they think they are attractive, or not attractive.”