In an analysis of 80 online dating profiles a few years ago, researchers weeded out the liars by comparing their stated height, weight and age to the real thing. It turned out 81 percent of people lied, though in minor ways: Men usually rounded up their height by half an inch, women fudged their weight by an average of 8.5 pounds, said study co-author Catalina Toma, assistant professor of communication at the University of Wisconsin-Madison.
Used fewer "I" pronouns. For example, instead of saying "I love to run in the mornings," they say, "Love to run in the mornings." The theory, Toma said: They are putting a psychological distance between themselves and their lie.
Used more negation. Instead of "I'm low-maintenance," they might say "I'm not high-maintenance." Again, the negation provides a buffer between the person and the lie.
Had shorter profiles. Lying is more cognitively taxing than telling the truth, so people may get tired and write less, Toma said. People may also fear that if they disclose too much they will get caught in their lie.
Used fewer negative emotion words, like "sad," "angry" or "bored." The use of more positive words by liars may be a strategic move, Toma said; happy, optimistic people are more attractive in the dating pool.