One of the huge perks of being a mom to five children is seeing how the interact. I grew up with only one sister and we fought all the time. As adults we've grown to accept our differences (for the most part) and get along fine (again, for the most part).
My heart warms when I catch the boys helping each other out.
Ben was tired from playing at the playground all morning, but insisted on driving this car to Grandma's so Declan could play with it there. His legs got tired...so Declan helped him out.