People dislike peeing next to each other. So there is a little dance you do when you go into a multi-stall bathroom. You casually glance (no bending over to check, that's rude) to see if other stalls are occupied, and if so, how many. If no other stalls are occupied, you pick your favorite stall, maybe because it's the one that always has toilet paper, maybe it's the one with a slower automatic flush, maybe it's got interesting graffiti.
However, what if other stalls are occupied? Then, quick math takes over. You need to pick the stall that is the furthest from other people's pooping. Sometimes this is easy and you can pick a stall two over, with a single stall barrier in between you and your peeing partner.
Got it? The article is written by “scicurious” over at Neurotic Physiology. (I paraphrased it slightly.) But since the post was titled “The Urinal Problem”, I assumed that scicurious was male . . . after all, only men use urinals, right?
Wrong. When a woman pees in a toilet, it’s magically *ta-dah!* a urinal. Now I know. (And knowing is half the battle!)