It might come as no surprise that smiling can make you feel happier. But the important thing here is that the smile must be sincere, it can’t be faked. If you fake it, you might even make yourself more unhappy, according to a 2011 study. 

The study examined a group of city bus drivers over a period of two weeks. They found that employees who put on a fake smile for the job were in a worse mood by the end of the day compared to when their shift began. But drivers who genuinely smiles as a result of positive thoughts actually had a better mood by the end of the day. So when you smile, make sure to smile like you mean it!