Unless you're a dancer or a poet, chances are you go to work for the paycheck or the sense of accomplishment, not to express your true self. In fact, one study from Deloitte found fully three quarters of us cover up some part of our identity at work to try to fit in.

So faking it at work is both common and understandable -- your clients and co-workers are going to expect you to be reasonably sociable, conscientious, and collaborative whether you really feel like it or not. But just because wearing a work mask is commonplace doesn't make it harmless, according to a fascinating recent post from Melissa Dahl for New York Magazine's Science of Us blog.

Faking it is physically harmful.

You might guess that forcing yourself to act in ways that are unnatural for your personality isn't great for engagement, but Dahl digs up preliminary research out of the University of Cambridge that suggests it's lousy for your physical well being too.

After analyzing the personalities, levels of satisfaction, and work performance of 300 employees of a U.K. marketing firm, researchers found evidence "that suppression of one's natural behavior is linked with poorer health -- specifically, a decrease in immune-system functioning. Your heart may start to pound and your muscles may tense, both indicators of autonomic arousal, the physiological manifestation of stress or anxiety," Dahl reports.

Extroverts actually have it worse.

What other interesting findings did the research reveal? Introverts have been having a bit of a cultural moment lately, thanks to high-profile boosters like Susan Cain, but according to this research it's actually extroverts who are harmed most when they're forced to cover up their natural sociability at work. Put simply, sitting quietly at a desk and not communicating seems to be mildly torturous for the inherently chatty.

"Extroverts suffer when they pretend to be introverts at work, and more so than introverts who pretend to be extroverts. When naturally talkative and social people had to be quiet and solitary for long periods of time at their desks, they reported less job satisfaction and more stress than the extroverts whose jobs allowed them to act like themselves," Dahl writes, noting that "this was especially true for the younger employees at the organization."

And if I have to fake it...

All of which is academically interesting but less than practically useful for those who are forced by their employment situation to act counter to their real personalities. However, scientists do offer a common-sense suggestion if you're among this group -- make sure you set aside at least some time in your day to take off the mask.

"It's crucial to allow yourself some sort of restorative period, meaning time to revert back to your true self," Dahl says. So an extrovert who spent the morning alone and immersed in work should consider taking a few friends out for a sociable lunch, for example. "Without that restorative time, you run the risk of your true nature 'leaking out,' perhaps in ways you don't expect," she warns.