Part of the positive psychology field. An excerpt:
So, what has science learned about what makes the human heart sing? More than one might imagine ? along with some surprising things about what doesn't ring our inner chimes. Take wealth, for instance, and all the delightful things that money can buy. Research by Diener, among others, has shown that once your basic needs are met, additional income does little to raise your sense of satisfaction with life (see story on page A32). A good education? Sorry, Mom and Dad, neither education nor, for that matter, a high IQ paves the road to happiness. Youth? No, again. In fact, older people are more consistently satisfied with their lives than the young. And they're less prone to dark moods: a recent survey by the Centers for Disease Control and Prevention found that people ages 20 to 24 are sad for an average of 3.4 days a month, as opposed to just 2.3 days for people ages 65 to 74. Marriage? A complicated picture: married people are generally happier than singles, but that may be because they were happier to begin with (see page A37). Sunny days? Nope, although a 1998 study showed that Midwesterners think folks living in balmy California are happier and that Californians incorrectly believe this about themselves too.
Read more about Positive Psychology from UPENN's website: