As AI-generated content takes over the internet, humans are becoming more and more vigilant about differentiating bot-written copy from genuine human writing. Last week, LinkedIn even became the first major platform to add a button that lets users report “AI slop.”
But how can users be sure what they’re reading isn’t actually the product of an LLM?
While there are some widely regarded tells of AI writing, those stereotypes may not be as reliable as they seem. A new report by The Economist analyzed the state of AI writing in 2026, identifying the telltale AI patterns readers should look out for, as well as the red herrings that don’t actually point toward artificial intelligence.
The Economist compared its own articles to versions of the same articles generated by top AI models, including OpenAI’s ChatGPT, Anthropic’s Claude, Google’s Gemini, and xAI’s Grok. Its sample also included writing from other news outlets such as The New York Times and The Washington Post, as well as excerpts from popular novels published between 1950 and 2022. Altogether, it compared 55,940 sentences and 1.2 million words.
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What not to look for
Perhaps the most characteristic sign of AI writing is the overuse of the em dash—the dash that is about the width of a letter “m” and is used to emphasize extra details or asides in the middle of a sentence. Although em dashes have long been a favorite convention of writers, the rise of AI has led many to strike the punctuation mark from their prose for fear of readers assuming their work wasn’t human-made.
But according to the report, em dashes are no longer a surefire sign of AI-generated content. Of the major models tested, only Claude used em dashes more often than human writers.
In actuality, a lack of punctuation is a better indicator of text being AI-generated, says the report. It also found that large language models (LLMs) use fewer commas, semicolons, and parentheses than humans, instead crafting overly long sentences with “and” as their most overused word.