If you're worried that a joking e-mail might be misconstrued, read it aloud in a deadpan voice before clicking "Send."

Most people know that humor or sarcasm can easily fall flat when expressed via e-mail, yet psychologists find that most people are still confident that they will be understood. Psychologist Justin Kruger calls this "everyday egocentrism"—the natural tendency we all have to see things from our own perspective. "Because we know we're trying to be sarcastic or funny, we egocentrically assume our audience will, as well," he says. It's a hurdle that we can't completely overcome, even when we are trying to put ourselves in someone else's shoes, he says.

In a study of adults, Kruger, a professor at the University of Illinois at Urbana-Champaign, found a simple way to make sure written words hit their mark. His team asked senders to read their sarcastic or serious e-mails aloud just before sending them. One group had to read the statements in a tone inconsistent with the intended meaning (reading a sarcastic statement in a serious tone or vice versa). By forcing participants to get beyond their own subjective interpretation of the e-mail message, overconfidence disappeared, Kruger says.