Another shocker that shouldn't have been: Wealth levels have a limited impact on happiness. Again, this is no surprise to biologists, Ketelaar says, because money is a relatively recent development in the history of human evolution. "Of course individuals aren't built to track wealth," he says. "Prior to agriculture, you couldn't have a society that could amass wealth."In other words, it's the chase that is thrilling. Getting what we want is often not so thrilling.
Clues to our behaviors can be found in the brain chemical dopamine, which is the key to the body's reward system. Strangely, in chimpanzees, dopamine levels peak not when they are going to get an award but when they realize the award is coming. That's very similar to our response to money.
For chimpanzees, this kind of brain chemistry can lead to strange behavior. In an essay, Stanford biologist Robert Sapolsky described a chimp that chased a prospective mate far beyond what would be reasonable, because the mate dropped occasional signals that she might be willing--maybe, someday. Sapolsky referred to this as the "pleasure and pain of maybe." The chimp was willing to go to great lengths for a hypothetical reward.
There's something about setting goals and pursuing them that makes us happy. Achieving goals isn't so important, it's the struggle to achieve.