I have to either strongly disagree with the outcome of this research or disagree with the definition of happiness used here. If you were to ask parents (myself included), if having children makes you happier in life, I think you would get a resounding yes it does! Having kids is stressful at times, and you can be constantly tired and stretched to your limits but the heights of joy one experiences as a parent has no bounds. I'd hate to think that the majority of parents think of child rearing as some sort of meaningful suffering...