"Turning that frown upside down" might not just be wishful thinking if you want to have a better day. According to a new study, smiling can actually make you feel happier.

While the effect might not last long, researchers from the University of Tennessee and Texas A&M say  they've proven that facial expressions can affect people's moods.

"It appears that the physical act of smiling can make us feel happy, that frowning can make us feel sad, that scowling can make us feel angry," says Nicholas Coles, a PhD student in social psychology and lead researcher at UT.

The study's conclusions were the result of 138 separate studies on the subject spanning the past 50 years, and involving more than 11,000 test subjects from all over the world.

The effect can vary from person to person, the scientist explains -- and while he notes smiling more won't "cure" somebody who is depressed, it can give them a much-needed boost.

It can't hurt to give it a try.