IN EVERY nursery there is one child known as the Biter. Who suffers the most from this child's delinquency? Not his classmates, whose bite marks quickly heal. It is the Biter's mum and dad, who endure sideways glances from other parents when dropping him off in the morning and fret constantly that their own poor parenting has produced a monster.

Arthur Brooks was once the father of a Biter. For a year, his son gnawed on boys, girls, siblings, friends and so many guests that he had to be removed from his own fourth birthday party. Mr Brooks worried, argued with his wife, lost sleep and sought professional help. So he speaks from experience when he says that having children does not make you happy.

Happily for the reader, his book, “Gross National Happiness”, is not a memoir. It is a subtle and engaging distillation of oceans of data. When researchers ask parents what they enjoy, it turns out that they prefer almost anything to looking after their children. Eating, shopping, exercising, cooking, praying and watching television were all rated more pleasurable than watching the brats, even if they don't bite. As Mr Brooks puts it: “There are many things in a parent's life that bring great joy. For example, spending time away from [one's] children.”

Despite this, American parents are much more likely to be happy than non-parents. This is for two reasons, argues Mr Brooks, an economist at Syracuse University. Even if children are irksome now, they lend meaning to life in the long term. And the kind of people who are happy are also more likely to have children. Which leads on to Mr Brooks's most controversial finding: in America, conservatives are happier than liberals.

Several books have been written about happiness in recent years. Some have tried to discern which nations are the happiest. Many more purport to offer a foolproof guide to self-fulfilment. Others wonder if the obsessive pursuit of happiness is itself making people miserable. Mr Brooks offers something different. He writes only about Americans, thus avoiding the pitfalls of trying to figure out, for example, whether Japanese people mean the same thing as Danes when they say they are happy. And he writes intriguingly about the politics of happiness.

In 2004 Americans who called themselves “conservative” or “very conservative” were nearly twice as likely to tell pollsters they were “very happy” as those who considered themselves “liberal” or “very liberal” (44% versus 25%). One might think this was because liberals were made wretched by George Bush. But the data show that American conservatives have been consistently happier than liberals for at least 35 years.

This is not because they are richer; they are not. Mr Brooks thinks three factors are important. Conservatives are twice as likely as liberals to be married and twice as likely to attend church every week. Married, religious people are more likely than secular singles to be happy. They are also more likely to have children, which makes Mr Brooks confident that the next generation will be at least as happy as the current one.

When religious and political differences are combined, the results are striking. Secular liberals are as likely to say they are “not too happy” as to say they are very happy (22% to 22%). Religious conservatives are ten times more likely to report being very happy than not too happy (50% to 5%). Religious liberals are about as happy as secular conservatives.

Why should this be so? Mr Brooks proposes that whatever their respective merits, the conservative world view is more conducive to happiness than the liberal one (in the American sense of both words). American conservatives tend to believe that if you work hard and play by the rules, you can succeed. This makes them more optimistic than liberals, more likely to feel in control of their lives and therefore happier. American liberals, at their most pessimistic, stress the injustice of the economic system, the crushing impersonal forces that keep the little guy down and what David Mamet, a playwright, recently summed up as the belief that “everything is always wrong”. Emphasising victimhood was noble during the 1950s and 1960s, says Mr Brooks. By overturning Jim Crow laws, liberals gave the victims of foul injustice greater control over their lives. But in as much as the American left is now a coalition of groups that define themselves as the victims of social and economic forces, and in as much as its leaders encourage people to feel helpless and aggrieved, he thinks they make America a glummer place.

Extreme happiness

So much for right versus left. Mr Brooks also finds that extremists of both sides are happier than moderates. Some 35% of those who call themselves “extremely liberal” say they are very happy, against only 22% of ordinary liberals. For conservatives, the gap is smaller: 48% to 43%. Extremists are happy, Mr Brooks reckons, because they are certain they are right. Alas, this often leads them to conclude that the other side is not merely wrong, but evil. Some two-thirds of America's far left and half of the far right say they dislike not only the other side's ideas, but also the people who hold them.

Oddly for a political writer, Mr Brooks thinks his country is doing pretty well. Americans are mostly free to pursue happiness however they choose with little interference from the state. Well-meaning coercion is less common than in Europe, though it can still backfire spectacularly. He cites this example: a county in Virginia recently banned giving food to the homeless unless it was prepared in a county-approved kitchen, to prevent food poisoning. Churches stopped ladling soup, and more homeless people were forced to scavenge in skips. This hurt not only the hungry, but also the volunteers who might have found satisfaction in helping them. The surest way to buy happiness, argues Mr Brooks, is to give some of your time and money away.