Look, whatever else happiness is, it’s also some kind of chemical reaction. Your body making and experiencing a cocktail of hormones and other molecules in response to stimulus. Brain reward. A thing that feels good when you do it. We’ve had millions of years of evolution that gave a reproductive edge to people who experienced pleasure when something pro-survival happened. Those individuals did more of whatever made them happy, and if what they were doing more of gave them more and hardier offspring, then they passed this on.Yes, I said. Sure. At some level, that’s true of all our emotions, I guess.I don’t know about that, she said. I’m just talking about happiness. The thing is, doing stuff is pro-survival—seeking food, seeking mates protecting children, thinking up better ways to hide from predators...Sitting still and doing nothing is almost never pro-survival, because the rest of the world is running around, coming up with strategies to outbreed you, to outcompete you for food and territory...If you stay still, they’ll race past you.