This study from Notre Dame indicates that our children are happy to learn about our religion from us, if we'll only tell them about it.
In our culture, talking about religion is so gauche, worse than talking about money or s*x or gross physical ailments. But unless we do make our religious feelings clear, we'll be drowned out by stronger competing voices.
This one from a BYU study says that oldest children get thousands of hours more attention from the parents--and that's not just when they're babies. The study compared children aged 4 to 13, and the attention difference adds up to 20-30 minutes a day.
My heart has really been pricked by this, and I resolve--among other things--to give my second-born more individual attention when he gets home from school.
A friend told me about this next one, so I can't document. She says the study compared adult siblings and found that the greatest predictor of the closeness of their relationships as adults was not how well they got along as children but how much time they spent together as children. So those hours of bickering bear good fruits.
For other studies that support contentious and messy families, see this post.