According to the tenets of one new age spiritual leader, "Humans were designed to be happy, creative and in harmony with the universe at all times." So a "permanent state of natural ecstasy" is within reach. Then again, that spiritual leader--a man named Rael, founder of the Raelians--also believes humans were created by a race of 4-ft.-tall space aliens.
For better or worse, humans seem to have been created by evolution, not aliens. And that is the key to understanding happiness: why it exists, what kinds of things bring it to us and why hanging on to it is harder than Rael suggests.
Among the differences between natural selection and space aliens is that natural selection isn't a conscious creator. It is just a process. It preserves traits that help get an organism's genes into the next generation. Still, biologists talk metaphorically of natural selection having "designed" human features "for" certain tasks. Intestines are for digesting food, ovaries are for making eggs, testicles are for making sperm--and in all three cases the contribution to natural selection's bottom line, genetic proliferation, is obvious. But what is happiness "for"?
Happiness is for getting us to use our intestines, ovaries and testicles. People so reliably pursue food and sex because eating and copulating release neurochemicals that make them feel happy. And the reason this neurochemical rule is part of the human heritage is that the genes responsible for it have, understandably, done well for themselves. Just compare their fate with the fate of any genes that ill-advisedly made eating and sex consistently nauseating.
The general principle: genes that dish out pleasure in ways that have helped propel them through the generations are the genes that are with us today. So the laws governing happiness were designed not for our psychological well-being but for our genes' long-term survival prospects. That fact, when pondered at length, can induce unhappiness.
But first the good news. Eating and copulating aren't the only ways to aid genes, and so aren't the only things that bring happiness. Helping your offspring thrive is a natural joy booster. So is excelling at work or play; during human evolution, impressing people could be good for your genes. Indeed, so various were the avenues to genetic proliferation that lots of not obviously animal activities bring happiness: making friends, being part of a team, even helping the needy.
Now back to the bad news. Happiness, though designed to materialize under lots of circumstances, is also designed to evaporate. If the bliss that comes from copulating never ended, then an animal would copulate only once in a lifetime. If, back in the hunter-gatherer environment of human evolution, wowing folks with a display of skill or courage left you permanently high, your stature, and hence your reproductive prospects, would slowly fall as more restless rivals outdid you. Among natural selection's mottoes is, "Stay hungry." That is, Don't stay happy.