Answer: Selfie Photos

Everyone, it seems, has an opinion on the matter of “selfie” photos: the cultural phenomenon of photographing oneself (and usually others) with an inward turned camera phone. Commonly bandied about arguments include that selfies are evidence of how, well, self-absorbed Western culture has become or how narcissistic Millennials are.

While such arguments are just reincarnations of the age old “the kids aren’t alright” and “society is going to hell” arguments that have been repeated generation after generation, we can actually blame selfies for something. It’s not narcissism or the fraying of the delicate fabric of society, but a much more tangible problem: lice.

Generally lice infestations are the province of children because children often do things like share each other’s hats, are in close proximity to each other, and will frequently huddle while playing. Typically, lice infestations die down as children grow older and stop stealing each other’s winter caps, bumping heads together, and leave behind the tumultuous play of childhood.

Recently, however, doctors have seen a noticeable rise in lice infestations in teenagers. To blame? The much maligned selfie. In order to get everyone into the photo it’s common for people to cluster together tightly with their heads touching which, in turn, provides a perfect way for lice to jump from one host to another.