Someone read something I'd written recently — a perfectly ordinary paragraph, nothing to do with data — and told me, kindly, almost apologetically, that it "read a bit like AI." I asked what had given it away. The answer, delivered with the confidence of a person who'd learned it from a thread somewhere: the em dashes. The little horizontal lines I've been scattering through my sentences since I was a student, two decades before there was a language model to be accused of imitating. Reader, I was more annoyed than the moment strictly deserved.

Because here's the thing they didn't know they were telling me: that punctuation was mine first. I studied language and communication before I ever touched a pipeline — before "data" was my noun of choice — and the em dash is not a tic I picked up from a chatbot. It's a tool I was taught, deliberately, by people with red pens, and one I've loved for as long as I've loved writing anything at all.

What the em dash actually does

Let me defend it properly, because it deserves a defence. The em dash is the most versatile piece of punctuation we have, and its versatility is exactly why careful writers reach for it. A comma joins. A colon promises. A semicolon balances two thoughts that could stand alone. But the em dash does something none of those quite manage: it breaks. It lets a sentence swerve mid-stride — a sudden aside, a held breath, an interruption you can hear — and then either close the parenthetical and carry on, or land the whole thing on an emphatic final clause the way a comma never could.

It's the punctuation of voice. It puts the rhythm of speech onto the page — the pause where a speaker would tilt their head, the dash where they'd cut themselves off to add the better thought that just arrived. I use it because I write the way I talk, and I talk in interruptions and second thoughts. Stripping the em dashes out of my prose wouldn't make it more human. It would make it sound like someone else.

The tell is backwards

Now the part that genuinely gets under my skin, because it's not just a personal slight — it's a small failure of reasoning that's spreading.

Why do the machines use em dashes so much? Because we do. Large language models learned to write by ingesting a mountain of careful human prose — books, essays, edited journalism, the accumulated output of everyone who ever paid attention in a writing class — and that prose is full of em dashes, because they're a mark of writing that's been thought about. The model reaches for the em dash for precisely the reason a good writer does: it read a great deal of good writing, and good writing uses it.

So the "tell" is exactly inverted. The AI doesn't write like a robot. It writes like a person who was taught to write well — and the consequence is that the people who were taught to write well now get mistaken for the robot. We handed the machine our best habits, and now our best habits are being cited as evidence against us. It would be funny if it weren't quietly corrosive.

The thing we're about to lose

Here's what actually worries me, past my bruised ego. People are starting to write worse on purpose to prove they're human. I've watched it happen — colleagues chopping their sentences short, deleting the dashes, roughing up their grammar, adding a deliberate typo, sanding the composure out of their own prose so nobody accuses them of being a language model. Flattening themselves to pass a test no one should be administering.

That's the real cost. Not that a machine can now produce a competent paragraph, but that we're teaching ourselves to distrust competence — to read care as a warning sign. A well-made sentence is becoming suspicious. And if the way to seem authentically human is to write badly, we have got the whole thing exactly upside down, because writing well was one of the more human things we ever learned to do.

The machines learned the em dash from careful human writers. Now careful human writers are told the em dash makes them sound like machines. Somewhere in that loop we started treating good prose as a confession — and that's the part worth refusing.

Where the accusation has a point

I'll be fair, because a defence with no concession is just a grievance. There is a version of AI text that overuses the em dash — a relentless, evenly-spaced rhythm of them, every sentence built to the same shape, dashes deployed not for meaning but as a texture. That can be a genuine sign of prose generated without intent. But notice what the tell actually is: it isn't the em dash. It's the absence of intent — punctuation as wallpaper rather than as a decision. The fix for that was never to abolish the mark. It's to write with purpose, which good writers were doing long before any of this and will keep doing long after the panic passes.

This connects to something I've believed since I first argued that a number is a message before it's a fact: the point of writing, and of the punctuation inside it, is to carry meaning cleanly to a reader. That's the whole job. An em dash that serves the reader earns its place. One deleted purely to dodge suspicion serves no one — least of all the reader, who now gets a clumsier sentence so the writer can pass a vibe check.

Keeping them

So I'm keeping my em dashes. All of them. I earned them the slow way — a degree in how language works, a decade of writing for audiences who'd notice, a great deal of red ink and rewriting. The machine is welcome to borrow the habit; it learned from the same books I did. But it doesn't get to make me apologise for a piece of craft I had first and used well.

If my writing reads like it was made with care, that's not a bug to be scrubbed out until I sound sufficiently human. It's the point. The em dash was mine before it was ever the machine's — and I have absolutely no intention of giving it up to win an argument I never agreed to have.