If you've ever shared food with someone you work with, or passed notes about that one guy in your office who always chews with his mouth open and sneezes all over everything (you know who I'm talking about), chances are you might be married and not even know it—married to a work spouse, that is.

What's a work spouse? It's a close platonic partnership with one of your coworkers, and a recent study suggests that 65% of Americans have one.

That's no wonder, says Harvard Business School historian Nancy Koehn. A "work spouse"—beyond helping someone get through the day—can also make employees happier, more productive, and have stronger emotional engagement with the company for which they work. 

"Individuals in the workplace with whom you have a closeness—emotional, professional, and ultimately, interestingly, a collaboration that is informal—[help] how you roll with the punches, travel the rollercoaster of an office or factory, and make your way through the world of work," Koehn said.

Koehn said that work spouses can be invaluable sounding boards for ideas, a person you can come to for professional guidance, and even a helping hand in navigating the often-sticky world of office politics.

"Here's someone who can help you sort it out who isn't you and has your interest at heart, a buffer against all the stuff that happens, someone to laugh with," she said. 

Plus, there are the logistical perks: "You get to the office, and here's a cup of coffee your work spouse has put on your desk," Koehn said.

Who says the institution of marriage is dead?

To hear more from Harvard Business School historian Nancy Koehn, tune in to Boston Public Radio above.