Public bathrooms come in many shapes, sizes and cleanliness levels. Some of these spaces are spotless, some come with bathroom attendants and some come with a helpful list of phone numbers for a variety of services. One thing we’ve never bothered looking into, however, is how to pick the best stall. Until now.

Thanks to Science of Us, who recently combed through “mountains of research” on bathroom behaviour so that nobody else has to, we now have a comprehensive guide that’s host to tons of “valuable” research (depending how seriously you value cleanliness) regarding the public space that’s primarily used for private means.

Research has determined that, if presented with three empty stalls, men will go left 28 percent of the time and go right 32 percent of the time. The most popular decision among men, however, was to use the first available stall/urinal. Men apparently don’t give a shit where they, well, shit.

But while this idea may be true for stalls, urinals prove to be a completely different animal, as they introduce the ever-present ailment of a shy bladder – which is one of two social phobias that men boast a higher rate of than women. Research confirms that, the closer men are to another person at the urinal, the longer it takes them to get that golden stream flowing. This proved true when a man was alone, when he had one urinal as a buffer and when men peed side by side.

But let’s get back to a bathroom’s cleanliness. Research suggests that men should avoid the middle stall and urinal, as this one’s getting the most wear and tear. If stalls were occupied, men ventured closer toward the entrance, meaning, by process of elimination, choosing the stall farthest from the entrance is arguably the cleanest, as the fewest people void their bowels in that toilet. For women, the opposite was found true: she should head toward the stall closest to the door.

Of course, there are a number of variables often involved in these decisions. Like pee on the toilet seat, or that special brand of monster who doesn’t bother to flush. The summation of all this research also determined people define “unclean” in different ways. For example, more than eight of 10 bathroom goers deem a public restroom “gross” if a dispenser is out of toilet paper while 76 percent feel this way if a soap dispenser is empty.

Worse than that, it appears that, whatever you do, you’re going to leave a public washroom dirtier than you did going in, because washing your hands after using a public bathroom is relatively pointless. Research found that soap dispensers in public washrooms are covered in fecal bacteria, so your hands often end up filthier than they would if you didn’t wash them. Who knew the guy you silently judge for refusing to wash their hands in the bathroom actually had the right idea all along.

Some people are so opposed to filthy public bathrooms that 30 percent of refuse to return to a restaurant with an unsanitary restroom; this predilection was found to increase with age.

So there you have it, dudes. If you wish to have the cleanest bathroom experience possible, head to the stall or urinal furthest from the door and don’t wash your hands. You might get looks from clean freaks but you’re the one who has the last laugh.