AI Writing Study Finds 13,000 New Telltale Phrases

A new study from marketing firm Graphite has identified roughly 13,000 words and phrases that may indicate AI-generated text, with the phrase "this matters" appearing 116 times more often in AI content than in human writing. The study highlights distinct patterns for major models: Anthropic's Claude Opus 5.5 frequently uses phrases like "looking ahead the" and "dependable," while OpenAI's Astra overuses "does not establish" 275 times more than Claude. Opus also uses fewer qualifiers and more superlatives than Astra. Notably, Claude's output is becoming more human-like over time, with em dash usage down 99% from its predecessor, while Astra is trending in the opposite direction. The findings come from a company with commercial interests, so results should be viewed cautiously.