Next time you make your measurements, be sure that you are not told which couples have kids and which don't. It would also help if the childless older couples were randomly chosen from as a set as possible. Likewise the old couples with children used as your control should be chosen randomly from as complete a set as possible. When you've got your results, get back to us.
Ah, so any opinion that's not "scientific" isn't worth posting? Utter bravo sierra. Humans form opinion based on their own experiences, and that's all se_ohio_young_conservative was talking about. Notice the key phrases like "seems to me".