The earliest advice about happiness came from religion, and it was usually: “Don’t expect too much.” “Man is born to suffering as the sparks fly upward”, as Job expressed it. The Greek philosopher Epicurus was a good deal more optimistic. “We say that pleasure is the beginning and end of living happily”, he taught more than 2,000 years ago, and recommended avoidance of both politics and religion. Advances in hedonistic technology have more or less stagnated since then, but now something new seems to be happening. Scientists, especially economists on a holiday from their abstractions, are bending their minds to the problem.

Can modern technology crack the secret of happiness? It seems unlikely, because there is a paradox in asking after the secret of happiness. Most people know, or think they know, that money doesn’t make you happy; nor does success or even the pursuit of pleasure. And yet like all modern peoples, Americans spend their lives pursuing these desirable things anyway. There is clearly something self-defeating about a situation in which everybody is devoted to projects they already know will fail to make them happy.

In the modern world, the way you face up to a problem is by trying to get at the facts about it. Social psychologists, neurologists, theologians, economists and many other specialists have now been industriously collecting the facts for many years. They have learned a lot by simply asking large numbers of people how happy they feel, thus creating a kind of “happiness profile” for many sets of people—nationalities, professional groups, political partisans, married and unmarried couples, religious believers and many more. No one looking for such a profile of the American people could do better than consult Arthur C. Brooks on Gross National Happiness.

Here is a breezy and engaging survey—typically by an economist rampaging through the fields of social psychology and neurology—of what modern research seems to have uncovered and thus revealing how Americans feel about themselves. Some of Brooks’s reports will undoubtedly irritate many readers. It seems, for example, that Republicans are as a group significantly happier than Democrats, and Christians happier than secularists.

Can these profiles reveal the elusive secret? Republicans seem to be happy because they accept American society as...