As the saying goes, "fake it until you make it." But when it comes to smiling that's not exactly true. A new study from Northwestern University has found that pretending to smile actually makes us feel worse than if we hadn't smiled at all.

For subjects that believed smiling was a way to express a positive emotion or good feelings, smiling actually made them feel better. But for people who felt that smiling was a tool to help them mask negative feelings, smiling actually made them feel worse. This flies directly in the face of previous research that claimed that smiling can make you feel better in and of itself (and show tunes that command that you should "put on a happy face.")

RELATED: 5 Simple Tips To Help You Stress Less

"Telling people to fake it until they make it, at least as far as their mood is concerned, might be something that actually makes them miserable," says Aparna Labroo, a psychologist at Kellogg School of Management at Northwestern University. "So sometimes it may be better to let them resolve their negative feelings." Solid advice. [FastCo.Design]