Soul Pancake's experiment in happiness is bound to make you smile, and maybe even pick up the phone.
Turns out it takes more than just being grateful to increase happiness -- you have to express that gratitude too.
Based on a 2005 study of positive psychology, Soul Pancake asked participants to write down as much as they could about someone who's made a powerful positive impression on their life. The participants thought that was the end of it, until they were asked to call that person and read what they'd written about them.
Participants wrote about professors, siblings, parents and friends, and the calls almost always ended in a puddle of happy tears on both ends of the line.
Here's an interesting stat: When you express gratitude, happiness levels jump up an average of 15 percent.
So go thank someone right now!