I think the fine folks at NCBI ROFL covered this one recently, but it’s too good not to share.
Have you ever been in a terrible mood, and someone tells you to smile? It usually doesn’t make your mood any better to be TOLD to smile, but what if you actually DO smile? Does it help?
Well, according to this paper, actually smiling may really help. But if you’re holding chopsticks in your mouth in a truly ridiculous manner, can you really HELP feeling a little better about life?
Kraft and Pressman. “Grin and Bear It : The Influence of Manipulated Facial Expression on the Stress Response” Psychological Science, 2012.