Imagine this: You’re a cardiac surgeon who is pushing into the five-hour mark of a complicated seven-hour surgery. You ask a nurse for a specific tool, and he drops it. It’s now contaminated and useless. The nurse stands dumbstruck until you snap at him to hurry up, grab another tool, and stop being so clumsy. You were rude, but he deserved it, right? He’ll get over the uncivil remark and everybody will move on. But that “moving on” actually might not happen — according to a recent study, rude comments in high-pressure medical settings could have potentially deadly effects on patients.

The study, “The Impact of Rudeness on Medical Team Performance: A Randomized Trial,” which was published in the September issue of Pediatrics, shows that a rude comment from a third-party doctor decreased performance among doctors and nurses by more than 50 percent in an exercise involving a hypothetical life-or-death situation. “We found that rudeness damages your ability to think, manage information, and make decisions,” said Amir Erez, an author on the study and a Huber Hurst professor of management at the University of Florida. “You can be highly motivated to work, but if rudeness damages your cognitive system then you can’t function appropriately in a complex situation. And that hurts patients.”

An experiment that Erez and his colleagues conducted between two teams one being told off how terrible their performance was fared badly compared to the other team who were not criticized but only asked if they learnt anything from the exercise.

The rudeness had dramatic effects. The teams who experienced it struggled to cooperate, communicate, and do their jobs effectively, all of which caused their performance to plummet: They misdiagnosed the illness; they forgot instructions; they didn’t ventilate the patient well; they didn’t resuscitate well; they didn’t ask for help when they needed it; doctors asked for the wrong medication, and nurses mixed the wrong medication. Overall, the rude comments appeared to cause a 52 percent difference in how well teams diagnosed the disease, as measured by three independent judges who were blind to the study’s thesis, and a 43 percent difference in how well they treated it. In the real world, as Erez pointed out, these performance discrepancies could have made the difference between the tiny patient living and dying.

These studies — including one Erez is a lead author on — suggest that disruptive behaviors like rudeness are so powerful because they spread like a contagion and sabotage a person’s working memory, which plays a crucial role in our in-the-moment ability to learn, reason, comprehend, and recall information.

While Erez wasn’t surprised that rudeness affected doctors’ and nurses’ work, he did say he was surprised by the magnitude of the effect rudeness had on doctors’ working memory. It’s troubling, he pointed out, given how often medical workers experience rudeness caused by stress, burnout, and miscommunication all the time. For example, a 2010 study shows nearly two thirds of health-care workers in operating rooms have witnessed rude behavior, and nearly one half have been on the receiving end. Because of this frequency, Erez said he expected that the experienced medical teams in his experiment would get over the rude comments and keep working effectively — especially given that their task was diagnosing a newborn in an emergency situation (albeit a simulated one). “But we found consistently and dramatically that rudeness isn’t something people can easily get over,” he says. “It’s not something that you can postpone emotionally to a later time because it affects the cognitive system.”

Christine Porath, an associate professor at Georgetown University who is an expert on the effects of incivility and is not involved in Erez’s study, said she wasn’t surprised by the findings.

Erez and Porath both say that hospitals need to take a more aggressive stance against rude behaviors among medical staff, and doctors need to consider the long-term effects of acting rudely toward one another. Because, as it turns out, these everyday slights could be catastrophic for patients.