'Don't Worry, Be Happy': Optimists Have Lower Cortisol Levels

It comes as no surprise that people who see the glass half full tend to have a better time dealing with stress. However, up until a recent study, scientists were unable to determine exactly why.

According to researchers from Concordia University's Department of Psychology, optimists tend to look at themselves during difficult situations instead of comparing their luck to others. In fact, the study shows that levels of the "stress hormone" cortisol, known for causing individuals to pack on the pounds, is also less present in individuals with positive attitudes.

Researchers tracked 135 older adults, ages 60 and up, over a six year period, examining saliva samples five times a day to monitor cortisol levels.

Participants were asked to report on the level of stress they perceived in their day-to-day lives, and to self-identify along a continuum as optimists or pessimists. Each person's stress levels were then measured against their own average. Doing this helped to provide a real-world picture on just how individuals handle stress.

Researchers note that pessimist tended to have a higher stress baseline than optimists. They also had trouble regulating their system when they go through particularly stressful situations. "On days where they experience higher than average stress, that's when we see that the pessimists' stress response is much elevated, and they have trouble bringing their cortisol levels back down. Optimists, by contrast, were protected in these circumstances," said Joelle Jobin, a co-author of the study, via a press release. 

He also writes that a surprising finding during the study was that optimists who generally have more stressful lives tend to secrete higher cortisol levels than expected shortly after they wake up.

More information regarding the study can be found in the American Psychological Association's Health Psychology journal.