It is a truth universally acknowledged that, if you give Generation X-box a hand-held device capable of taking and instantly transmitting photographs of what is in front of them, they will use it the wrong way round.
All over the world, in places where our forebears would stand and gaze in awe, visitors now turn their backs on the monument or landmark and grin inanely for the benefit of a phone held at arm's length in front of them.
Some have gone further; on a recent trip, I noticed that many of the younger Far Eastern tourists carried small extending poles which enabled them to snap their own faces from a greater distance. How many selfies do you have to take for it to be worth investing in a gadget like that?
Meanwhile, such is the ubiquity of the genre and its more dubious spin-offs that schools are now devoting entire lessons to explaining to children why it is inadvisable to photograph one's genitalia and send the results to other people, a practice which I don't recall being mentioned back in the days of the Kodak instamatic.
Since the idea of taking endless photographs of oneself is likely to appeal most to the immature and the terminally narcissistic and the process is far from foolproof, the internet abounds with examples which mine a rich vein of idiocy.
'Is this the most dangerous selfie fail?' asks the Telegraph, reporting on the man who tried to take a selfie in front of half a ton of angry pot-roast at the bull-running in Bayonne last week. Well, no, actually; a sad little collection of Google entries testifies to the foolhardiness of taking selfies on the edge of a cliff or at the wheel of a car.
And at the weekend, in what should be a shoo-in for a Darwin award, a Mexican managed to shoot himself in the head while posing with a loaded gun; his intention, apparently, was to load 'cool' pictures of himself with the weapon onto facebook.
When ET and his chums show up a few millennia hence and study what remains, it's quite likely that they will date the decline of what was once human civilization to the invention of the phone camera and social media.