Noble born children realy had a Prügelknabe, another child, that was in the same age.
They were raised together by servants and often became best friends.
The Prügelknabe was punished, when someone, who was not part of the nobility, wanted to punish the noble born child, because it was not tohom to beat a noble born child.
Because the children were best friends, it was kind of a psychological punishment to the noble born child, because his friend was punished because of him.
btw i think the english translation for Prügelknabe is whipping boy.