Why are conservatives so much happier than liberals?

Studies show that they are (or at least think they are or say they are). But why? My first guess, without reading on in the article is that they mind their own business. They think taking care of their own work and family is enough, and liberals feel they must worry about how everyone else is doing.

According to the column, by Arthur C. Brooks, the president of the American Enterprise Institute:

Many conservatives favor an explanation focusing on lifestyle differences, such as marriage and faith. They note that most conservatives are married; most liberals are not....
The story on religion is much the same. According to the Social Capital Community Benchmark Survey, conservatives who practice a faith outnumber religious liberals in America nearly four to one....

An explanation for the happiness gap more congenial to liberals is that conservatives are simply inattentive to the misery of others. If they recognized the injustice in the world, they wouldn’t be so cheerful....

People at the extremes are happier than political moderates. Correcting for income, education, age, race, family situation and religion, the happiest Americans are those who say they are either “extremely conservative” (48 percent very happy) or “extremely liberal” (35 percent). Everyone else is less happy, with the nadir at dead-center “moderate” (26 percent).

What explains this odd pattern? One possibility is that extremists have the whole world figured out, and sorted into good guys and bad guys. They have the security of knowing what’s wrong, and whom to fight. They are the happy warriors.