Obsession has a punctuation mark — and it's the em dash. Since ChatGPT burst onto the scene, users have noticed something peculiar about its writing style. The AI loves em dashes. Really loves them. Not just as occasional punctuation but as a go-to tool for connecting thoughts, creating dramatic pauses, and inserting asides.

This isn't random. The model's training data included mountains of professionally edited texts — books, academic papers, journalism — where em dashes flourish. ChatGPT simply learned what it saw. Good writers use em dashes. Great writers use them with purpose. AI uses them everywhere. With 77% of devices now featuring some form of AI, these writing patterns are becoming increasingly prevalent.

Online communities have taken notice. Some call it the "ChatGPT hyphen" — a dead giveaway of artificial authorship. Imagine that. A sophisticated AI betrayed by a horizontal line. Users have tried instructing the model to ease up on the dashes. It rarely works. Old habits die hard, even for algorithms.

The irony? Em dashes actually signify sophisticated writing in human hands. They're the punctuation of The New Yorker and well-crafted novels. They create rhythm. They add emphasis. They're elegant — or they were, until they became too common.

Now, with ChatGPT among the internet's most-visited sites, this stylistic quirk has consequences. What happens when a single AI's writing habits influence millions of texts daily? The distinctive becomes ordinary. The elegant becomes expected. The model generates text probabilistically, which explains why certain patterns like em dashes appear with such frequency. Experts like Aileen Gallagher emphasize that em dash usage alone is not conclusive evidence of AI-generated content.

Writers and editors are paying attention. Some avoid em dashes entirely now — not wanting their work mistaken for AI-generated content. Others adopt them defiantly. The battle for punctuation authenticity is real. And stupid. And somehow significant.

The model doesn't understand style intuitively. It can't know when it's overusing a good thing. It only knows patterns and probabilities — not restraint or variety. So the em dashes continue, spreading across the internet like digital kudzu.

A humble punctuation mark, once the sophisticated choice of editors and authors, now signals something else entirely — the fingerprint of artificial intelligence trying just a bit too hard to sound human.