## Should You Leave the Lavatory Toilet Seat Up or Down: a Game Theoretic Approach

More than anything inflight you hope your seatmate actually uses the lavatory when needed. You use the lavatory even when the seat belt sign is on. Just be sure to only use the lavatory in your own cabin. And if you leave it stinky ask the flight attendant for a used pack of coffee grounds.

Chris McGinnis surveyed people about whether it’s best to leave the toilet seat up or down in an airplane lavatory.

Overwhelmingly people people you should leave the seat down.

I know and abide by the rules around terrestrial toilets used by both sexes: leave the seat and lid down when done. It’s the right and polite thing to do.

But are rules in the air different? I’ve often thought so but when I posed this “up or down” question in conversations or on social media, the answer was a resounding “down” (many in ALL CAPS with several exclamation points) from women.

From men, the response was mostly “down,” but mixed.

American Airlines Boeing 787-9 Premium Economy Lavatory

Like most things, what people believe (‘conventional wisdom’) is wrong.

My quick take, which I left on Chris’ Facebook query and which he quoted, was: “Men and women should leave the toilet as-is, there’s a chance the next person will be of the same gender. This limits the number of times that the toilet must be touched.”

However as with most things there’s academic literature on the subject, with math.

• Having each person leave the toilet seat down means the male incurs all the seat movement cost, and the female none.

• The combined incremental effort moving the toilet seat is greater with an ‘always down’ strategy than simply leaving the seat as-is.

A fair and efficient approach would see to:

(1) Minimize the joint total cost
(2) Equalize the respective total costs
(3) Equalize the respective incremental costs

Singapore Airlines Airbus A380 Suites Lavatory

In fact, the mathematically correct answer to these criteria is to have the male split their approach, such as leaving the seat up in the first half of the flight and putting the seat down in the second half (or vice versa, but a stable rule is necessary “to avoid the notorious ‘middle of the night surprise'”).

I still believe the unique nature of an airplane lavatory with its confined spaces, public use, and turbulence suggests the only correct rule is one that minimizes touching anything in the lavatory as a public health imperative.

So… airplane lavatory toilet seat, up or down?

Gary Leff is one of the foremost experts in the field of miles, points, and frequent business travel - a topic he has covered since 2002. Co-founder of frequent flyer community InsideFlyer.com, emcee of the Freddie Awards, and named one of the "World's Top Travel Experts" by Conde' Nast Traveler (2010-Present) Gary has been a guest on most major news media, profiled in several top print publications, and published broadly on the topic of consumer loyalty. More About Gary »

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1. […] curious query of airplane lavatory toilet seat etiquette. As I’ve grown older, I’ve become a bit more of a germaphobe myself, so I tend to agree […]

1. JustSaying says:

Neither answer is right. The lid should be closed to keep the fumes from coming into the cabin

2. henry LAX says:

i usually pull both the seat and cover down for the flush but that’s only to muffle the painfully loud vacuuming noise of the mostly-waterless flush. nothing really about hygiene or turbulence or etiquette.

3. ATX says:

Close the cover. Fushing creates an invisible cloud of yucky stuff called “toilet plume” that’s hurled into the air by the force generated from flushing. The main bacteria found in the plume is E. coli, which can cause bacterial gastroenteritis, a.k.a. abdominal pain and diarrhea. Outbreaks of gastroenteritis on airplanes and cruise ships have been linked to the plume, as well as a SARS outbreak in 2003 when a patient in Hong Kong may have spread the virus with a flush. The room is very small. nuff said.

4. Rico says:

I thought I’d read that tray tables were the germiest thing to touch on an airplane. So, tray tables up or down?

5. Basil says:

I’d call that “Game of Thrones” 😉

6. DCDan says:

As a male, I will close the lid to the commode using my feet to be polite yet minimize how much I touch the toilet.

7. Doug Swalen says:

I always close the cover. But I think this story is making a mountain out of a molehill. And unless you don’t wash your hands (and shame shame shame on you if you don’t) it really doesn’t matter if you touch the seat or not…you’re going to wash your hands either way.

8. Jeff says:

From a “politeness” standpoint, my experience:

Toilet seats are almost impossible to put in an “up” position that actually holds. It’s infuriating. So if I get one to stay up, I would imagine there is a 50/50 chance I did the next person a BIG favor. Conversely, a light cough will bring most airplane toilet seats down or perhaps the sound vibrations from your voice gently whispering “please just stay there” to the toilet seat will almost always bring it back down. So net politeness is maximized by leaving it up (if this miracle can actually be performed).

That said, many of the hygienic positions stated above are very compelling and from that standpoint I could be convinced that it should always go down before flushing.

9. Graydon says:

There’s a toilet on all planes? Are you kidding me? What’s next a shower? SMH.

10. Chris says:

I leave it up. A lot of men have bad aim. Leaving it up means there is less likely to be pee on the toilet seat.

11. Julian says:

Lufthansa and Emirates F class toilets are too pretty to not put the lid down.

12. Donald Mamula says:

I have the lid closed for as much of my time in the “blue room” as possible. Simple reason:

I want to reduce, as much as possible, the chance of something falling in from one of my pockets. Don’t want to lean over and have anything go “plunk”.

13. Elizabeth Houck says:

Lid and seat down every customer, every time. Wash your hands and use the paper towel to open the door latch upon lav exit. That’s how I roll 😉

14. Simple answer… always put the seat & lid down. Nobody wants to see the inside of a toilet bowl any more than they need to. And you certainly don’t want things getting dropped in there by accident!

15. D74 says:

To use hygiene to justify not touching the toilet seat to put it down is ridiculous considering so many men do not even wash their hands… and even more just run their hands under some water as i that kills bacteria….

16. DavidB says:

Always lid down. But can’t count the number of times I’ve lifted the lid to find the remains (fortunately always liquid) of the previous user unflushed! Even happened on my last flight this past Saturday. Use Kleenex in hand when lifting and closing the cover (and seat) and handiwipes to swab the seat if using it…then placing a sheet of seat cover tissue. Also check the rim and often find that’s worth a swop down with a handiwipe or damp Kleenex tissue. Yes, heavy maintenance due both before and after use.

17. Ralfinho says:

Interesting, that some suggest a different behavior for men and for women. Since lavatories are usually supplied with toilet seat covers I think there is absolutely no need to pull up the seat. Everybody should take a seat no matter what the gender is.
So always seat down, seat cover on top, person sitting down, doing business, flushing … and maybe lid down or not. And, of course, washing hands and using towel to open the door.
The thought that people pee while standing is really disgusting, especially during flight.

18. Jon says:

Ralfinho I assume you’re a dude. But you sit down?? Speechless

19. DaninMCI says:

You put the seat and lid down. That way men who are lazy have to lift it up to pee and not likely to pee on the seat. Although they likely still won’t wash their hands. Women will be forced to lift the top lid and appreciate men more who do lift the seat 🙂

20. MickiSue says:

If you care about germs getting on your own clothes as you flush, then leave the danged seat down. Because microparticles of urine and feces flying through the air…

The solution to touching the seat? Wash your hands. Because UGH if you don’t. People who seriously debate whether or not to put the seat down because they don’t wash their hands are the reason that I use a paper towel to open the lavatory door in public places.

21. Leave the toilet seat down and wash those hands with a hard scrub for 30 seconds.