Like a flock of chickens hunting grubs and seeds, humans appear to be hardwired to follow a social pecking order. Researchers at the National Institute of Menal Health conducted an experiment in which subjects played a computer game for money. They were told they were competing simultaneously against others whom they couldn't see and were assigned a rank based on their playing skill.

You’re a ball of anxiety: head pounding, jaw clenched. And you could feel worse down the line, since on-going stress can wreak havoc on your health. But new devices help you stop tension by picking up on early warning signs. They precisely monitor a bevy of biological stats, wirelessly deliver the data to your computer or phone in real time, and guide you in calming exercises that help you chill out instead of losing your cool.

Clinical psychologist Alain Brunet of McGill University in Montreal doesn’t usually torture his patients. But lately he has been pressing those with post-traumatic stress disorder, or PTSD, to relive emotionally scarring incidents. For some it’s rape, others battlefield trauma. When his patients get particularly upset—crying, shaking, blood pressure rising—he gives them a 25-year-old hypertension drug called propranolol. The idea, though, is not to lower their blood pressure.