Stress triggered by deadlines hampers staff creativity, reduces effectiveness, and negatively impacts performance. But if that’s the case, why is it so hard to ask for an extension on projects with unrealistic due dates?

Writing for the Harvard Business Review, Ashley Whillans, an assistant professor at Harvard Business School, explains two barriers that keep people from negotiating deadlines—even though doing so may lower your stress and improve your output.

Infographic: How to be a less-stressed leader

Barrier 1: You're (overly) worried about what your boss will think

Many workers fear their bosses will judge them harshly for requesting an extension. But according to Whillans' research, this worry is often misguided.

For example, in one study, Whillans and her team asked 900 participants from various industries to complete a challenging writing sample on a tight timeline. Each writer was told that another participant would act as their manager, evaluating the sample and deciding if the writer should receive a cash bonus.

The participants were told they could request an extension at any time. One group of writers were told that, if they requested more time, their manager would be informed. The other group was told that the manager would not be informed if they asked for an extension.

Despite being told that the quality of the writing sample was all that would be judged, participants who were told their manager would be aware if they requested an extension were 31% less likely to negotiate the deadline.

But requesting an extension paid off, the researchers found. Participants who asked for more time were rated by managers as producing higher-quality writing.

In a second study, supervisors were asked to review the writing samples from the first study. This time, the participants who were acting as managers were told which writers had requested an extension and were asked about their perceptions of those workers.

On average, managers rated the samples submitted by participants who had extended their deadlines as higher in quality. But that's not all: They also perceived those participants as much more competent and motivated.

According to Whillans, this research suggests that "employees are hesitant to request extensions out of concern that their supervisors will judge them negatively for doing so, and as a result, they forgo the chance to improve their performance in a manner that their supervisors would care about."

Barrier 2: You're confused about what your manager actually cares about

In another study, Whillans and her team asked 200 employee and 200 manager participants to think of a project with an adjustable timeline. They found "that employees consistently overestimated the extent to which managers cared about completing work quickly."

In reality, managers cared much more about the quality of their employees' work.

Of course, some projects don't have easily movable deadlines. Yet even in these scenarios, separate research has found, managers don't judge employees as harshly for requesting an extension as the employees themselves expect.

What managers—and staff—can learn from this research

Based on her research, Whillans has takeaways for both managers and staff.

Managers, Whillans says, should clearly communicate deadlines—and the flexibility around them—to staff. This is critical for staff to understand what's more important for the project: speed or quality. Managers should also empower staff to share when they're feeling overwhelmed.

And for staff, Whillans says, "[m]ost of the time, quality matters more than speed. When in doubt, ask your boss for that extension—they're a lot less likely to judge you for it than you might think.” (Whillans, Harvard Business Review, 12/10).