Stress has been the source of a number of ailments and problems for as long as humans have been on this planet. Even before the word stress existed. The idea behind the study is that when your brain is mildly stressed is caused the body to try to come up with solutions to problems. This caused the brain to function at a higher level which can cause you to be more confident. It is also believed that its people who live sedentary lives that could benefit the most from a bit of stress.