If you're stuck in the middle seat, you might be wondering who owns the armrests on a plane.

Here's a hint: It's not you.

Oh, I know the conventional wisdom says that if you're in a middle seat, you own the armrests. But as economy class seats shrink, and as the pandemic lingers, it's increasingly clear that the conventional wisdom is totally wrong. 

The economy class cabin is a shared space -- and getting access to a coveted parking spot for your elbows often means thoughtful negotiation, having some compassion, and compromise.

"The middle seat armrests belong to no one," says airline analyst Timothy O’Neil-Dunne. "It's common space and you better treat it that way."

Why the armrests are a shared space

A few airlines have declared a truce in the armrest wars for at least the next few months. Delta Air Lines is blocking middle seats until Jan. 6. Southwest Airlines has taken similar steps to allow social distancing.

The budget airline announced Wednesday that it will keep them empty until Nov. 30. As of Sept. 17, JetBlue and Alaska had not said whether they will extend their moratorium on selling middle seats when their policies expire, on Oct. 15 and 31, respectively.

For other airlines, it's back to 2019. 

Taking control of the middle space armrests can lead to unpleasant, even dangerous, confrontations between passengers. So let's go over the reasons why you shouldn't assume that you own the armrests on your middle seat.

Delta will block middle seats into January: But the airline plans to fill more of its seats

Happy Thanksgiving!  Southwest Airlines will leave middle seats open through November

When people think something on a plane is theirs, you get a confrontation like the one Scott Curkin recently witnessed on a recent flight from Las Vegas to Phoenix.

A small-framed passenger sat between him and his CEO. After takeoff, the man claimed both armrests on the middle seat. 

"Then he went on a rant about how, as the occupant of the middle seat, he deserved to have both armrests," remembers Curkin, the vice president for a marketing company in Raleigh, NC. 

When his CEO failed to yield the armrest, the man in the middle asked him to "step outside" to settle their differences. The plane hadn't yet reached its cruising altitude.

"He actually challenged my CEO to a midair fight," Curkin says.

Fighting about who owns the armrests on a plane is selfish

First, there are no guarantees that your seat will come with any kind of armrest in economy class. It's not in the airline contract of carriage, the legal agreement between you and your airline.

It's not specifically guaranteed in your reservation. (You book a seat, not a pair of armrests.) Staking a claim on both armrests is a lot like leaning your airline seat all the way back. It's selfish.

Just as recline space is almost nonexistent, there's also virtually no room to spread out in economy class. Average seat width has shrunk from 18 inches to 17 inches or less. We're stuck.

Should the person in the middle get some kind of priority for the armrests? Some say yes. But even experts who feel the man in the middle deserves the armrests acknowledge there are exceptions to this rule.

Nick Leighton, an etiquette expert who hosts the "Were You Raised By Wolves?" podcast, does believe the middle seat armrests belong to the passenger in the middle seat -- except when they don't. 

"If there are extenuating etiquette circumstances, like a larger person in an adjacent seat, then the armrests aren't yours," he says.

But it could be worse. Some passengers feel armrest real estate is a "first-come, first-served" proposition, says Leighton. That's a recipe for a mid-air melee.

By the way, pay no attention to the shrill voices in the blogosphere who try to shout me down on this subject. These self-appointed critics wouldn't be caught dead in an economy class seat. If they want to participate in this debate, let them fly in the back of the plane with the rest of us.

The last word on who owns the armrest? You have to share

So who owns the armrests on a plane? They're not yours. They're ours. Just like the space behind you, they must be shared and negotiated with your fellow passengers.

Shane Chapman, the senior vice president of airline industry relations at Ovation Travel Group, says neither the airlines' contract nor their policies address armrest ownership. "This issue just comes down to common courtesy," he adds.

That strategy seems to work best. The "ask nicely" approach can avert almost any territorial dispute in economy class, says Adam McBride, a frequent economy class air traveler who hosts "The Costa Rica Experience" podcast.

If you want to claim an armrest, make sure your fellow passenger is OK with it.

"Asking nicely almost always works," he says.

And what if it doesn't? 

"Sometimes you need to be a bit more direct," advises etiquette consultant Jodi RR Smith. "Say, 'It's tough to travel in such a confined space and I do have a touch of claustrophobia. Please do not lean on me. Thank you.'”

But the armrests aren't yours, no matter where you sit. They're community property -- whether you like it or not.

How to avoid an armrest war

Even if you don't subscribe to the "man in the middle" or "first-come, first-served" attitude toward middle seat armrests, conflict is inevitable. Here are a few tips for sorting it out:

Communication is key. "I usually indicate to the passenger beside me that he or she can use the armrest," says Elliott Katz, author of "Being the Strong Man a Woman Wants: Timeless Wisdom on Being a Man."

"If the other passenger is a decent person, he or she will reply in the same way -- indicating it's fine for me to use the armrest."

Remain calm. Look for obvious solutions like switching seats rather than getting involved in a potentially dangerous altercation. Being civil and polite is far more effective than threatening your seatmate with violence.

"What separates us from many animals is our ability to empathize and work together. If you do not need space, offer to share," says Smith, the etiquette consultant.

Ask for help. Flight attendants often must mediate disputes over who owns the armrests on a plane. "There is no gray area when it comes to moderating them," says Mateusz Maszczynski, an international flight attendant who publishes a blog for airline crew members.

"Airlines have sold you a service to get from Point A to Point B and everyone has been sold a seat with a certain width. It’s your duty to keep all your body parts within the width of that seat, including your elbows."