Selfie Sticks in various forms have been around for a long time. Since the first caveman saw his reflection in a pool of water, we have been fascinated by our own image. In the first Century, the Romans invented hand-held glass mirrors, and all of us have been looking back ever since.

Mirrors are everywhere. Carnivals have mirrors that can make you fatter or thinner, and interior designers use reflections to make rooms look more spacious. When I was growing up, one of my favorite things about the barber shop was the mirrored walls and the line of gradually smaller Mr. Smith’s stretching off into the distance. I also loved the Fleer Bubble Gum, complete with a comic on the inside of the wrapper, which the barber handed out. As you can guess, this was quite a few years ago.

Although mirrors can be handy for making sure you don’t have a piece of spinach stuck in your teeth, there is a fine line between practical self-assessment and vanity. On the one hand, we laugh at Arthur Fonzarelli for constantly checking his appearance. In the meantime, shrinks tell us to “take a look in the mirror”- psychobabble for the need to pause now and then for a few moments of self-reflection.

Psychologists, seeing an opportunity for funded research in the mirror, have suggested four rather dark traits – narcissism, psychopathy, Machiavellianism and self-objectification – which may be related to the modern incarnation of the mirror known as a selfie. If you were already sensing that the spread of selfies was a bit creepy, these results won’t help.

Studies of men between the ages of 18 and 40 eliminated Machiavellianism from the list (selfie-takers aren’t typically ruthless and manipulative) but found that narcissism and self-objectification were common traits, particularly in those who edited their images before posting online. For those whose self-worth centers on physical appearance, Photoshop will gladly play digital devil to your Dorian Gray.

As for the psychopaths, they are much too impulsive to waste time touching up a selfie. If your Facebook friends are sharing crappy amateurish snapshots fresh from the smartphone, be very scared.

Whether we are harmlessly embracing the latest fad or riding a new wave of personality disorders remains to be seen. One clear and noteworthy difference between the mirrors of history and a modern selfie is that the mirror image is mercifully short-lived. To avoid permanent psychological injury, seek immediate medical attention for a reflection lasting more than four hours.