More evidence against the "Grumpy old men" myth

A while back I posted about the idea we have in this country that the elderly are more likely to be sad, grumpy, curmudgenly, etc.  Despite this widespread belief, there are a handful of surveys that suggest that older people are generally happier than their young and middle aged counterparts (and generally more well adjusted).  Of course, since these surveys always asked different people (one group above a certain age versus another group at a middle age, etc.) one could hypothesize that times were simply better so many decades ago, thus arguing that the reason older people tend to be happier is because they grew up in some idealized "Leave it to Beaver" type culture, and the younger people are not as happy, not because of their age, but simply because they have had to live and grow up in a different world.  Well, a recent longevity study, that is, one that followed the same people as they aged, suggests that it really is age that confers feelings of well being.
http://www.sciencedaily.com/releases/2010/10/101028113819.htm
I guess they really are your golden years.