We connect with others online more than ever, making it tougher to tell when someone is lying, says communications professor Jeff Hancock of Cornell Univesity. The main tipoffs:

Wordiness: Liars use more words and details to try to sound believable. If a colleague emails from home how bad her cough sounds and how clogged her head feels, chances are she's not that sick.

Avoidding I's: Liars use more he, she, they and we pronouns than I. "We're late because the cabdriver didn't know where he was going" is more likely to be a lie than "I couldn't get a cab."