You’ve heard the saying “kill them with kindness.” Sadly, a modern version of that old saw might be “kill them with rudeness.”

New research finds that workplace sass not only hinders team productivity but can threaten lives.

A team led by researchers from Indiana University and the University of Florida conducted five studies to gauge how negative workplace interactions impact teams in corporate and medical settings.

In one study, 40 teams were asked to build a bridge out of newspaper and tape, with some subjected to rude comments as they worked.

In another, 24 teams took part in a medical scenario where they tried to save a simulated infant patient while an observer lobbed either neutral or negative comments.

The other studies were online simulations that asked participants to complete virtual team tasks while a rude or neutral observer weighed in.

Researchers used these undoubtedly annoying tactics to measure what is called Social Value Orientation, or the degree to which people put group interests above their own.

They found that rudeness triggered a defensive response, making the team less likely to share information and properly distribute work.

Wherever the negativity came from, researchers found that workplace rudeness consistently made people more self-centered and their team less productive. Adding an element of danger, rudeness contributed to poor task execution, including lifesaving medical procedures.

So, the next time your team is under pressure and you’re tempted to offer a snarky zinger, remember that biting your tongue may hurt in the moment, but will pay off in the end.