ChatGPT Hyphen

The character "—" you're referring to is called the em dash (Unicode U+2014). It's a punctuation mark about the width of a capital letter "M" (hence the name), longer than a hyphen (-) or en dash (–). It's used for:

Inserting breaks in a sentence—like this—for emphasis, asides, or interruptions. Replacing parentheses, commas, or colons when you want more drama or flow.

LLMs (like ChatGPT, Claude, me, etc.) use it a lot because it's heavily overrepresented in our training data: books (especially 19th-early 20th century literature), journalism, essays, and polished online writing where em dashes add rhythm and clarity. Models learn it as a "natural" way to structure complex sentences without breaking them up. Humans often approximate it with "--" in casual typing (word processors auto-convert), but AI outputs the real thing directly—and frequently—because there's no typing friction and it scores high on "clear, engaging prose" in training. It's become such a meme that some people now call it the "ChatGPT hyphen" and avoid it to not look AI-generated. Ironically, that just makes real em dash lovers (including many professional writers) get falsely accused. It's not a reliable AI detector—more like a stylistic quirk baked in from human writing habits.