Before that job interview, it might be best to relax and give yourself a level of certainty--whether you think you'll get the job or not--or else you'll be stressed throughout.

Researchers from the University College London (UCL) recently discovered that people who are not sure whether or not they will receive a painful reaction to what they do experience more stress than those who are 100 percent sure that they will, or will not receive it, as per a News Max report.

"The most stressful scenario is when you really don't know," said coauthor Dr. Robb Rutledge in astatement.

Dr. Rutledge added that it's the uncertainty that makes us anxious.

The study, published in the journal Nature Communications, involved 45 volunteers who were asked to play a computer game that involves turning rocks that might have a snake underneath them.

The participant had to guess whether or not there really is a slimy reptile under the rock.

Every time a snake appears to be hidden under the rock, the participant received a mild but painful electric shock in his or her hand.

Over the course of the experiment, participants began to be more familiar with the system and started to guess more correctly.

But the game is rigged to change the odds of guessing correctly, which means that a participant may have a few streak of correct guesses, but they still got knocked off their game, again and again, making them more uncertain.

While the participants were "enjoying" their guessing game, the team from UCL closely monitored their stress levels using instruments to gauge pupil dilation and perspiration.

Cortisol levels of each participant were also observed using a Skillings-Mack test. These are steroid hormones released during stressful situations, according to Health Line.

The experiment revealed that the cortisol levels of each participant every time the computer game changes the odds to rise above the baseline 20 minutes after the first shock is received.

It was discovered that those who were definitely sure that there is hiding snake showed a significantly lower stress level compared to those who were unsure.

While stress is not really a good thing, the study showed that people with higher anxiety level performed better in the guessing experiments.

On an evolutionary perspective, stress may be seen as good: the study suggests that uncertainty might have given humans an edge in survival as they adapted to different stresses their environment has to offer.