You really DO reap what you sow

The book The How of Happiness: A Scientific Approach to Getting the Life You Want describes several experiments showing that subjects became measurably happier, and maintained this happiness for months, if--once per week--they were EXTRA nice.  One day per week the subjects deliberately did five more acts of kindness than they would normally do.  The good deeds could be small or big, public or anonymous.  All that mattered was that the participants kept varying the good deeds so that they didn't become a chore.

What if the people already were habitually nice?  Did they still become measurably happier if they spent one day a week being EXTRA nice?  Yes.  The boost happened regardless of whether the subjects were habitually nice or habitually callous.  I'd bet that, in general, nice guys are happier than jerks, but the evidence suggests that if you want a BIG boost in happiness, take your good deeds to a higher level once a week.

Will I try this technique myself or encourage my family to do it?  Probably not yet.  We're already doing some of the other things recommended in the book such as weekly reflection on the things we're grateful for.  The author of the "How of Happiness" suggests picking just a few of her techniques at a time so that you notice the results and make a lifelong commitment to your new habits.