Stress has two faces, and only one of them wears you down

Stress has earned a reputation as something to always get rid of. That is only half true. In practice there are two very different things that go by the same name: the acute stress that flares up before a challenge and then subsides, and the chronic stress that never really goes out. They look the same in the body for a while. They do very different things to you over time.

The acute kind is old and, within reasonable limits, useful. The pulse rises, the gaze sharpens, thinking becomes briefly more pointed. It is the body’s way of preparing you for something that asks more of you than usual. A classic relationship in psychology, known as the Yerkes-Dodson law, describes how performance often follows an inverted U-curve: too little pressure gives sluggishness, the right amount gives sharpness, and too much lowers performance again. Moderate, short-term stress is therefore not the enemy. It can be exactly the boost a task needs.