this study was overviewed on the evening news.  the claim was that women are
happier when they are attaining maternal success at a young age and men are
happier when they achieve material wealth at an older age.  when i saw this
on the evening news some man actually said that the reason women are less
happy as they get older is because "their hormones get all whacky".

http://abcnews.go.com/Health/story?id=5479994&page=1

shay