In a study of more than a million Yelp restaurant reviews, Mr. Jurafsky and the Carnegie Mellon team found that four-star reviews tended to use a narrower range of vague positive words, while one-star reviews had a more varied vocabulary. One-star reviews also had higher incidence of past tense, pronouns (especially plural pronouns) and other subtle markers that linguists have previously found in chat room discussions about the death of Princess Diana and blog posts written in the months after the Sept. 11 attacks.
In short, Mr. Jurafsky said, authors of one-star reviews unconsciously use language much as people do in the wake of collective trauma. “They use the word ‘we’ much more than ‘I,’ as if taking solace in the fact that this bad thing happened, but it happened to us together,” he said.
Another finding: Reviews of expensive restaurants are more likely to use sexual metaphors, while the food at cheaper restaurants tends to be compared to drugs.