Why Does AI Prose Reach for the Same Mark on Every Page?
This is Essay 8 of 22 in the series Why Choose 100% Human Authors, addressed to readers who want to understand what a human author does that a machine cannot and why that difference matters to the experience of literary fiction.
A Mark with a History
The em-dash entered the English language in the fifteenth century. By the seventeenth it had become a standard feature of print: a mark capable of interruption, amplification, digression, and dramatic suspension. It is a legitimate and venerable instrument of prose, one that a skilled writer deploys with the same deliberation as any other device. Laurence Sterne used it to comic effect. Emily Dickinson made it the signature rhythm of her verse. Henry James employed it as a hinge between clauses he wished to press together without subordinating one to the other.
None of these writers reached for it on every page, in every paragraph, for every emphasis. They used it because they had something specific to do with it, and when they were done, they put it down.
A language model (LLM) does not put it down.
What the Machine Does
Here is a passage an LLM might produce:
The letter arrived on a Tuesday—she had not expected it—and for a moment she simply stood at the door, the envelope in her hand, uncertain whether to open it or to set it aside until she felt ready—if she ever would feel ready—to learn what it contained.
The em-dash appears four times in a single sentence. Each instance performs the same mechanical task: interruption, qualification, suspension of the main clause. The reader is not given a chance to feel the interruptions because they come in such rapid succession that they cease to function as interruptions. They register as habit.
Extend this for a page:
He arrived at the station late—later than he had intended—and found the platform empty. The last train—the one he had meant to catch—had gone. He stood there a moment, his bag at his feet, deciding—or trying to decide—what to do next. The city was behind him—a day’s travel at least—and ahead there was only the dark road and the distance he had not crossed.
Four sentences. Seven em-dashes. The prose has acquired a tic, a tremor that runs through every line regardless of whether the line requires emphasis or interruption or suspension. By the third sentence, the reader skips the content between the dashes because it is always a qualification, always the same parenthetical movement. The mark that should create emphasis has destroyed it through repetition.
The Problem of Default
The em-dash tic is not unique to generative AI, but AI produces it with a consistency that exposes its mechanical origin. A human writer reaches for the em-dash from habit or inattention and can be persuaded, by a good editor or by rereading with a cold eye, to hear the clutter. A language model reaches for it by default. It has processed thousands of pages in which the em-dash appears with high frequency, and without an aesthetic sense that registers excess, it reproduces it as though frequency were style.
The result is prose in which the em-dash is no longer punctuation. It is decoration, or worse: it is a nervous mannerism, the typographical equivalent of a speaker who fills every pause with a sound, not to convey meaning but because silence is uncomfortable.
There is a further problem. Not everything benefits from dramatic suspension. The em-dash is suited to certain moments, to the thought interrupted, the revelation withheld, and the aside that enlarges what surrounds it. When it appears in passages that require none of these effects, it applies dramatic pressure where no drama exists. The prose becomes breathless, pointed at nothing.
The kitchen was quiet—unusually so—and she put the kettle on.
She put the kettle on. Nothing in this act requires suspension. The em-dash imports a weight the sentence cannot justify.
What a Human Author Does
A writer who understands punctuation knows that its power is proportional to its restraint. The em-dash carries force when the reader has not been conditioned to expect it, when its arrival feels like a choice rather than a reflex.
In my work, I do use the em-dash. This is a considered decision. Yet I have found that the colon also performs most of what the em-dash is asked to do, with greater clarity and less drama. Where the em-dash creates a theatrical pause, the colon creates a logical one: it promises that what follows will illuminate what preceded it, and it keeps that promise without performance.
Some writers will use the em-dash and use it well, with the sparing precision that gives any mark its meaning. The point is not that the em-dash is wrong. It is that its rightness depends on a writer who knows when to reach for it and when to leave it in the drawer.
A language model has no drawer. It has only the reach.
Rio de Janeiro, the xxvii day of June, MMXXVI.
