I'd say it depends on the kid. I have a 22 year old that is about 15, a 17 year old that is about 12 and a 14 year old that is about 45.
Last year at a family funeral I sat two rows behind a couple of my cousins -- twin boys. At one point during the funeral, I look up to see one of them pulling the others arm hair. These boys are 57!!
Some days I think siblings bring out the worst in each other.