The German royalty used a disciplinary technique that would straighten
out any modern kid. A prince would be raised along with another child.
If the prince misbehaved, it was the other child, not the prince who
was punished. A child might be willing to risk a spanking for
outrageous behavior, but even a young kid would feel some guilt if his
spanking was administered to another kid. - from the Education section
of www.odd-info.com