Since the very early stages of life, we all experience some form of stress. Stressors can be mild to severe and can range from unsuccessfully longing for maternal milk in infancy, to recklessly wiggling on a motorbike to be on time to watch the NBA finals on TV, to breaking up a relationship.

All those events that we call "stress" have the capability of perturbing a given state of psychological and physiological equilibrium and moving it to a different level. The transition from crawling to walking has to be considered a form of stress as much as losing a job.

It is through a...