Children's surname

[jack]

If a couple lives together have different surnames and have a child, what's the most common surname for the child?

Comments

[kaberett]

Lots of "standard" solutions -- my family went with "give them both", but I know families that did "give everyone one parent's surname", and one family that gave presumed-boy-children the mother's surname and presumed-girl-children the father's. (Heterosexuals EVERYWHERE.)