When I was still in high school, I had a boss tell me I had a great smile, one that could really light up a room. It was a nice compliment, though I didn't think too much of it at the time. 

Fast-forward to today, and I've been thinking about smiles a lot more. Partly this is because I have a new baby daughter. And when she smiles, it's a showstopper. My mood changes instantly. I can't help but smile right back. This got me reflecting on smiling at work. 

"Service with a smile" is a familiar expression and we all try to put on a good face for customers and colleagues. But why, exactly, are smiles so powerful, and can we find ways to tap into the power of smiling at work? 

A little research suggests that there's definitely more to smiling than meets the eye. (Leonardo was on to something with the Mona Lisa.) A smile has the power to change how we see the world and how others see us. 

But there's one big catch: It's got to be authentic. And that's easier said than done. 

Facial feedback theory 

Charles Darwin may be synonymous with the science of evolution. But he also had another subject of interest: smiles. 

In the 1800s, Darwin developed an idea that scientists would eventually dub the "facial feedback hypothesis." He held that the simple act of smiling can actually make you happier, while frowning can do the opposite. 

Go ahead. Try it out. Molding your face into a big old smile does actually feel kind of nice. 

Since Darwin's time, psychologists have turned to innumerable experiments to test this hypothesis. Among the best known and widely cited studies was published back in 1988. In it, researchers essentially tricked people into smiling by asking them to hold a pen between their teeth. Participants were then asked to assess how funny a series of cartoons was. Those who were "smiling" consistently rated the cartoons funnier.

At work here are a combination of powerful biological and evolutionary forces. At the neurological level, smiling is said to spur a chemical reaction in the brain, releasing dopamine, which increases happiness, and serotonin, which reduces stress. At the same time, we're culturally conditioned from birth to associate smiling with happiness.  

It's got to be authentic or it doesn't work 

So should we all just slap on a big grin in the office? Well, it turns out that it's not that easy.

More recent research suggests that a forced smile doesn't necessarily bring benefits -- and might be worse than no smile at all. Scientists at the University of Tennessee did a metaanalysis of 300 facial feedback experiments conducted over 50 years. They concluded that, on the whole, the benefits of just moving your mouth into the shape of a smile were "extremely tiny" and often exaggerated. Uh oh. 

Another study published this year threw serious shade on the whole "service with a smile" ethos. It found that service workers who were obliged to smile for customers were more likely to engage in heavy drinking after work. The authors speculated that these employees weren't truly smiling at all, as much as putting on a mask for the benefit of customers and supervisors. (Well, duh.) 

To me, this gets to the heart of the matter. A real smile -- the kind you see take over the face of a toddler, for instance -- is a glorious thing. It's the manifestation of true happiness. Physiologically, this smile even looks different from a fake smile. A true smile (technically known as a Duchenne smile) engages not just the muscles at the corners of your mouth, but also the orbicularis oculi, which encircle the eye socket. In a real smile, the eyes smile, too, crinkling up on the corners 

Bringing smiling into business culture

At the end of the day, smiling -- really smiling -- does have benefits. The question is: Can we do a better job of letting those true smiles shine through on the job? I think so. To me, this starts with the cultural tone a company sets. The job might be serious. But that doesn't mean how we work has to be. Even more important is having a clear sense of mission and purpose on the job. Real joy and real smiles are predicated on people doing work they believe in and feeling they're making a difference.

Finally, I think founders and senior management can lead by example here. Don't hold back for the sake of decorum or save your smiles up for sales calls. If you're happy and you know it, show it -- it might just benefit you and your business.