Fake facial expressions actually work.
There are about eight (give or take) facial expressions that are intrinsic to all humans, regardless of culture. Here are the common ones:
Fear Now, have you ever heard the phrase "fake a smile?" People say to do that when you're feeling down so that you can feign strength to push through the day.
But here's the thing: faking a smile actually does make you happier!
Just like faking an angry expression can make you angrier all of a sudden. Repeat this for the other facial expressions.
This is because those intrinsic facial expressions are each hard-wired to our brains in a specific way so that when they're activated, both the corresponding physiological responses and emotional feelings will follow. This will work for every human; therefore it doesn't matter what culture one is from.
So if you make an angry face, your sympathetic nervous system will activate, increasing heart rate and preparing you for a fight-or-flight response. At the same time, your amygdala in your brain will stimulate feelings of anger. Intense.
Here's a practical application of this. Before a concert or stand-up comedy show, the house may send out a pre-show act to warm up the audience before the main act. This is smart, because the pre-show act will likely get you to smile. And because you'll already be smiling and happy from the pre-show act, you'll definitely be even happier for the main act. Mind blown?
So the next time you're feeling stressed or sad, fake a smile. I do this when I'm stressed, and it helps to remind me that all predicaments are temporary and have a silver lining. Side note: if there's something I would avoid, it's Resting Kanye Face: If this is you, seek help immediately.
Yes, I'm being facetious.
This answer comes from quora.com, the popular online Q&A service. Ask any question and get real answers from people in the know.