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The Boston Globe

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Miss Conduct

On a crowded plane, who gets the armrest?

Plus, advice on a friend who butts in.

Lucy Truman

On a plane or in a theater, who gets to put their elbow on the armrest? Is it ever OK to use both armrests when the seats are all taken?

P.L. / Lexington

When both ends of the seat row have armrests and all seats are occupied by two-armed adults, it is mathematically optimal for one person in a full row to occupy both armrests available, otherwise one armrest will go unused and its comfort-giving potential will be wasted. Those very same mathematics, however, those cold equations, indicate that it is statistically unlikely that this person would be you if pure chance and not your own self-interest were to reign.

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There is no convenient rule such as “keep to the right” for armrest assignment. One must pay some attention to the body language of the folks seated on either side, and engage in a wordless negotiation — a turn-taking dance, not sharp-elbowed jockeying for space. Armrest occupation is not an all-or-nothing proposition. One shifts position and cedes one’s space from time to time, especially on a flight lasting more than a couple of hours. Nor need one take up an entire armrest, especially if one has short little T. rex arms like Miss Conduct; I can prop my elbows cozily next to my rib cage and leave the front half of the armrest to a longer-limbed seatmate.

Folk ethics do hold that the person in the middle seat on an airplane — especially the dreaded middle seat of the middle column — gets both armrests as a consolation prize for not having an aisle or window.

Each time I introduce one of my friends to other friends, she begins e-mailing and texting them directly. Some of her outreach attempts are OK, but others are weird and overly effusive. If I say anything, her feelings will be hurt. Maybe she just wants to fit in with my friends, but in an awkward way? I usually include her when appropriate, but now I am beginning to hesitate. It feels like she wants to take over my life and friends, to some extent excluding me. Should I just ignore the behavior and limit introductions in the future?

K.Y. / Boston

Yes.

Sometimes people are just weird, and we have to keep a buffer zone around them even though we love them. This can feel wrong, because it can feel as if you’re punishing someone for something without even having the courtesy of talking to her about it to her face. In fact, I bet you thought I was going to yell at you for that very thing, didn’t you? But I’m not, because your helplessness at even describing exactly how she’s crossing boundaries tells me all I need to know.

This isn’t the kind of behavior you can address, because it’s not the kind of behavior the other person is even aware of. You can ask your friends to do specific things, but you can’t ask them not to be weird. You can only corral the weirdness.

You not only can corral the weirdness, you also may corral it. When a person’s behavior is making you uncomfortable, you have the right to do something about it even if you can’t perfectly articulate why it’s making you uncomfortable. Your gut feelings are sufficient justification to act. You don’t need an airtight case capable of holding up in a court of law. You only need a gentle social-engineering solution and the will to implement it, and it sounds like in this case, you have both.

Miss Conduct is Robin Abrahams, a writer with a PhD in psychology.

CONFUSED BY COMMUTING ETIQUETTE? Send your questions to Miss Conduct at missconduct@globe.com.

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