“While the physiological state wasn’t properly named until the 1930s, new research from The University of Western Ontario proves stress has plagued humans for hundreds, and perhaps thousands of years. The first study of its kind, published in the Journal of Archaeological Science, detected the stress hormone cortisol in the hair of ancient Peruvians, who lived between 550 and 1532 A.D. When an individual is stressed — due to real or perceived threats — cortisol is released into nearly every part of the body, including blood, saliva, urine and hair.”