From a New York Times blog dedicated to matters of health:

Researchers from the University of Virginia’s National Marriage Project recently studied the role of generosity in the marriages of 2,870 men and women. Generosity was defined as “the virtue of giving good things to one’s spouse freely and abundantly” — like simply making them coffee in the morning — and researchers quizzed men and women on how often they behaved generously toward their partners. How often did they express affection? How willing were they to forgive?

The responses went right to the core of their unions. Men and women with the highest scores on the generosity scale were far more likely to report that they were “very happy” in their marriages. The benefits of generosity were particularly pronounced among couples with children. Among the parents who posted above-average scores for marital generosity, about 50 percent reported being “very happy” together. Among those with lower generosity scores, only about 14 percent claimed to be “very happy,” according to the latest “State of Our Unions” report from the National Marriage Project.