Recently I’ve found myself using the smile emoticon a few times in emails. This is a new thing for me – I’ve never been one of those “happy face” people. But email is an imperfect form of communication, one where sometimes words are misinterpreted, jokes are missed, subtlety is nonexistent. The smiley face assures the recipient that my words are well-intended or light-hearted. But it also makes me smile when I insert it in the message.

Smiling is an innate response to feeling good. Ultrasound photos show babies in the womb smiling, especially when they are just about to fall asleep or wake up, moments that are thought to be pleasurable for them. They start smiling in response to other people by about 2 months old, and soon learn what an effective expression it is for getting attention. As we get older, we see that people respond to us more positively when we smile. A smile conveys gladness to see someone, respect, understanding, compassion or hospitality. Those who work in customer service know this – many of them have been trained to greet customers with a smile.

Smiling is also something we can do just for ourselves. When I first moved to my neighborhood, I used to see a woman out power-walking every morning, always with a big smile on her face. It was so noticeable that I referred to her as the happy lady. It turns out that smiling on purpose can change one’s “affective state” or mood. For instance, in one study, people who smiled while exercising felt better afterward than did people who frowned; and they also perceived that they had exerted themselves less.

There’s something called the “facial feedback hypothesis” which asserts that facial expressions have the ability to actually kick off emotional responses, even in the absence of other stimuli. At its most basic, this means that if you smile, you might begin to feel happier; and if you frown, you might begin to feel more sad or negative. This is more than just changing how you think about things. Neuroscience supports this hypothesis, and shows that going through the motions of happiness – such as smiling, laughing, and singing – can actually make us happy.

Smiling can also alleviate stressful situations. University of Kansas researchers designed an experiment to test different types of smiles during stressful tasks. “Standard” smiles use just the muscles around the mouth, and “genuine” smiles also engage the muscles around the eyes. Some of the participants were trained to hold neutral expressions, standard smiles or genuine smiles. Others were just instructed to smile. The experiment showed that either kind of smile resulted in lower heart rate levels after stress, with the genuine smile being the most effective. This tells me that smiling could be one of the easiest and most accessible forms of stress management there is.

“Sometimes your joy is the source of your smile, but sometimes your smile can be the source of your joy,” said Thich Nhat Hanh. Want more joy? Smile, laugh, sing. Repeat as needed.