Royal families often had a lot of inbreeding issues, because they wanted to keep their bloodlines pure, so some fresh blood from a commoner woks wonders.
Combine that with the upbringing in an environment that makes you believe you are something special because of your bloodline, and you can see the outcome.
Meanwhile, the half blood princes had to live in the real world, so she needed common sense.
So what I’m hearing is that royalty should be required to spend the first 10 years of life outside of the Palace, living as a commoner, as a requirement to maintain their status as a royal.
Can’t do much about the inbreeding. Apparently it makes them special.
Well, having a gene defect named after your family and the outcome of that defect visible as a family trait, makes you in a way special.
Just like the Habsburg chin in European History.
At least to maintain der right to the throne, the royals without political ambition could stay in their glasshouse.
No seriously, all the royal pure bloods in this family have issues. Meanwhile, it’s only the little halfling princess, born of a commoner, who managed to inherit common sense.