I wanted another child for myself, more than one child to enjoy and create treasured memories with. But, like many parents, I also wanted a sibling for my first child. Someone she could grow up with, share recollections with, commiserate about her parents with. Sure, it isn't all lovely scenes like this, but so far I haven't been disappointed. On the other hand, siblings increase their sphere of loved ones.
Older children receive a different kind of attention from younger siblings.
For younger children, older siblings can be some of the most important people in their lives, slightly larger versions of themselves to mimic, follow around and learn from. But he's never known loneliness, either. Watching him imitate his big sister's every move, right down to carefully licking his fingers the way she does after polishing off a cookie, I don't doubt that he has benefited from a different kind of attention. Maybe I've never sat and read to him as much as I did to her, but I also never crawled under the bed with him and waited there to scare Mommy. In other words, there are trade-offs.