Everyone knows the flu is contagious and why — people pass along their germs via grody handles and uncovered sneezes — but lots of other things are contagious for reasons that are a lot harder to pin down.

Yawning is the prime example, but scientists have shown that lots of other behaviors from laughter to being a jerk are also catching. It's not viruses or bacteria that are to blame in these cases, it's people's inherent tendency to empathy, our natural inclination to mirror the feelings and actions of those that surround us.

It's a reality we intuitively understand when we seek out a cheerful friend to give us a mood boost, or fret about what the less-than-super-nice new hire will do to the office culture. And it's also one we can use to our advantage at work in another interesting way, a new study suggests.

The Belgian research team behind the research tested 22 participants on a straightforward task in which they had to watch squares on a screen and respond quickly when certain colors appeared. The difficulty of the task could be dialled up or down so that it was fairly mindless or required real concentration.

The mystery of contagious concentration

The interesting bit happened when subjects were asked to perform this task in pairs. When one of the study subjects was performing well when the task was quite difficult (aka was concentrating and working hard), the researchers found that another participant seated next to him or her also increased their levels of effort and concentration, whatever the difficulty level of their task This was true even if the two subjects couldn't see each others' screens, so the result couldn't be down to mimicry of a particular technique for completing the task, for example.

“Somehow one person’s hidden mental effort seemed to influence the other,” the British Psychological Society's Research Digest blog says, summing up the results (the post also offers a deep dive into the study methodology if you're interested).

The mechanism for the effect wasn't clear. “The researchers don’t know what led one player’s levels of mental effort to contaminate their partner, but they speculate that perhaps it had to do with body posture. Maybe the person forced to concentrate extra hard adopted a more tense body posture and this sign of mental effort automatically influenced their partner to also concentrate extra hard,” writes BPS, but that's only speculation. Something more outlandish like a change in a person's scent could conceivably also underlie the effect.

But whatever the exact explanation, the takeaway seems pretty clear — concentration is contagious. And you don't need to know how this works to put it to use. Next time you really need to hunker down and work hard, try to find a spot next to a colleague who is just as nose down as you are (if not more so). It just might help you focus and pound through that pile of work faster.