The problem, which I have never been able to solve, is that my smile — the genuine, spontaneous, I-mean-it smile — is a lips-together situation. Something about the size relationship between my teeth and my lips (and possibly my cheeks) produces, when I attempt a full, toothy grin, not warmth and good cheer, but an image closer to a demonic figure from a medieval painting. The kind where the demon is about to do something to a sinner that involves fire and possibly biting.

I know this because I spent a certain number of hours when I was younger trying to smile in front of a mirror. I had noticed that some people have these wide, open, luminous smiles — lips naturally pulled back, teeth exposed. They have the sort of smile that makes you feel, when it’s directed at you, that you are the most important and delightful person in the room. I wanted that smile. I tried to produce that smile. What I produced instead suggested Jack Nicholson in The Shining (1980).

So I stopped trying. “I’m just not a smiler,” I said to myself, and since that day, I keep my lips together and hope for the best. 

Here’s the problem: I don’t think a smile is really about how you feel. It’s about how the other person feels. A smile is a social signal, a gift you give to the room, a way of saying: “everything is fine, I am glad to be here, you are safe with me.” It’s not an emotional report. It’s a gesture of reassurance. Which is why people ask for it — “Smile!” — the way they might ask you to hold a door. It’s a courtesy. It’s for them.

Which means that when someone can’t produce it — when the machinery just doesn’t work, when the teeth are the wrong size, or the lips won’t cooperate, or the cheeks refuse to do their part — there’s a faint social transgression involved. You’re withholding something. Even if you don’t mean to. Even if inside, you are genuinely delighted to be there.

Laughter is a different matter entirely, which is why I prefer it to smiling. Laughter is not a social signal. It’s involuntary — it erupts from somewhere below conscious control, grabs your breathing apparatus, and temporarily takes over your body. You don’t decide to laugh. It just happens. Which is why you can’t really fake it, not convincingly, anyway. And why, when it happens, it’s infectious — because everyone in the room knows it’s genuine. Nobody laughs on cue and fools anyone. 

Comedy writers, of course, try to suppress laughter. We are a competitive and jealous group, and laughing at a colleague’s joke in the writers’ room is a small concession, a point scored against you. But when something is truly funny — I mean, genuinely, structurally, perfectly funny — it gets through. It always gets through. And in 30 years of sitting in comedy writers’ rooms, I have never once seen anyone successfully suppress a real laugh. You can delay it. You cannot stop it.

For me, laughter is easy. Smiling is impossible.

So here’s what I do when someone complains about my pursed-lips-dimples-showing attempt at a smile: I open my mouth and pretend to be laughing. I say, “Take it again,” and then act as if I’m in the middle of a spontaneous guffaw. It always looks weird. I always look about 15 pounds heavier. But often the photographer is satisfied and moves on.

Not this time, unfortunately. This time, the photographer looked at the picture and appeared annoyed. She showed me her phone. “This is the best you can do?”

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I thought it looked pretty good. More honest than a smile, anyway. But she wanted the polite fiction, the managed gesture, the social signal that says everything is fine.

What she got was the real thing. Apparently, that wasn’t what she had in mind.

Rob Long is a television writer and producer, including as a screenwriter and executive producer on Cheers, and the co-founder of Ricochet.com.