No one looks forward to a job interview.

And running for president is a job interview for the highest governmental office, stretched out over a year and a half, with each word under heavy scrutiny by voters and media alike.

Sound stressful?

The people behind voice analysis smartphone app Sharecare put that to the test, using their software at Thursday’s Republican debate, as well as an earlier Democratic debate, to monitor candidates’ stress levels.

Here’s what they found:

Celebrity businessman and Republican front-runner Donald Trump has been repeatedly described as an outsider candidate this election. That’s particularly true when it comes to stress.

“His signature is low stress,” Sharecare chief innovation officer Erik Feingold told MarketWatch Friday. “He’s a real outlier.”

Most people feel their stress levels spike when they’re involved in a confrontation, differing in how they act afterwards.

By contrast, Trump maintains low stress even when he’s on the attack.

Feingold called it “remarkable,” though he said it can inspire deeply polarized in others, who either find it scary or a reason to trust the candidate.

This held true when Trump challenged fellow presidential candidate Ted Cruz at the GOP debate: the candidate’s stress levels increased slightly over the course of the confrontation but remained relatively low, as seen in the below Sharecare video.

Texas Sen. Ted Cruz, who public opinion polls say has a fighting chance of winning the Iowa caucus, does experience significant spikes in his stress level but he manages it “very well,” Feingold said.

One way he does this is by using humor to diffuse the situation.

Cruz also summons facts to his rhetorical disposal rapidly, Feingold said, no doubt a skill honed during Cruz’s time as a Harvard Law School debator. The candidate gets stressed when challenged but it quickly recedes once he’s brought information to his aid.

When the topic of his eligibility for president came up at Thursday’s debate, Cruz employed both tactics: pointing to Trump’s statements on the issue months before, then cracking, “Since September, the Constitution hasn’t changed. But the poll numbers have.”

Stress may be the top bipartisan issue this polarized election year.

Though Democratic front-runner Hillary Clinton and Cruz have little else in common, they respond to stressors similarly, Feingold said.

Like Cruz, Clinton uses humor to keep her stress down, he said.

By contrast, fellow Democratic candidate Bernie Sanders uses repetition of a similar message, or income inequality, regardless of the questions he’s being asked at a debate.

Sticking to that message “makes him appear more confident, calm,” Feingold said, though he cautioned that ShareCare analyzed less data on Sanders than on other candidates.

How do you measure vocal stress, anyway? Think of the software being like your most perceptive friend, the one who can tell you’re upset after just a few words.

(Or, with the jargon: Sharecare uses math functions that map out frequencies into a visualization, then noting repeating shapes or “fractal patterns.”)

The voice analysis is part of an app by the same name — Dr. Mehmet Oz and WebMD founder Jeff Arnold founded the company, Sharecare, Inc. — that tracks other aspects of health and wellness, including hours of sleep, diet and exercise.