More on having kids and happiness - comments by the Eyres here. A summation:
"Is this to say that those without children cannot be happy? No! But it is to say that children contribute to the happiness of everyone whether they are our kids or not. And it is to say that children give us a kind of happiness (and a level of unselfish love) that is not available elsewhere.
The happiness that children give us comes in moments! Golden, glorious moments of wonder when we see something so cute, or so beautiful or so noble or so perfect that we can scarcely contain the joy.
And let's give children even more credit than that. They not only teach us new and higher levels of love, but new levels of patience, of self-sacrifice, of discipline and of empathy.
The simple fact is that we need them as much as they need us, and they teach us as much as we teach them.
Do kids make us happier every day in every way? No. Do they lift our happiness and sense of well-being to a consistently higher plane and relieve us from stress and worry and strain? No. But do they give to us moments of the highest, purest joy we can find in this life?
Yes! A thousand times yes!" (Linda and Richard Eyre)