I am baised obviously.... but I think that is true, Cindycactus.
I think a lot of it is that when there are that many people, it means more work. And more work means more jobs.... and if you really want to keep things working smoothly, you start functioning as many individules in one team, with one goal..... You become closer that way. =) And the closer you are with your family, the more you respect and love them.
And for me at least, loving, respect and being friends as well as a daughter with my parents, I strive to obey them and to help my parents and siblings. I know that is the same way for many large families. =)
And just for the record.... I am in my late to mid teens right now. I spent a majority of my childhood being the one of 2 children. My family didn't start growing again untill I was 9, and I was 11 before it grew again. And since then it's grown a bit more.
I have become closer to my family since we've grown so much. :D