Are there any benefits to growing up with a sibling as opposed to being an only child?

Maybe companionship: As a father of 2 girls born 3 years apart, they are best friends and always have someone to play with, which is more important in our family than some, as we live in a rural area with few other kids nearby. But not all siblings get along so well. A good article that summarizes the myths and science related to only children can be found at http://en.Wikipedia.Org/wiki/only_child.

Possibly: There may be some affect on social interactions and friendship. However, studies have been mixed and there is no conclusive evidence that having a sibling will improve social interaction.