Genetical reasoning was that the biological offspring of a former “proven” monarch, would be more statistically likely to be also proven worthy.
Emotionally, the mythical concept of a child discovering his destiny was seen as more satisfying to the population than random selection, as was the glad reunion of parent and child when he successfully passed the test and his destiny was revealed.
Lastly, the sacrifice of a monarch’s own children (by letting them be raised by strangers, and possible killed) endeared him to the population, and encouraged the own monarch to raise the standards of education and prosperity for all his subjects, as his own children would benefit from it.
It might be worthwhile to secretly test a few randomly-selected commoners too. Claim they were royalty all along if they pass, otherwise leave as little evidence as possible that the test took place.
Genetical reasoning was that the biological offspring of a former “proven” monarch, would be more statistically likely to be also proven worthy. Emotionally, the mythical concept of a child discovering his destiny was seen as more satisfying to the population than random selection, as was the glad reunion of parent and child when he successfully passed the test and his destiny was revealed. Lastly, the sacrifice of a monarch’s own children (by letting them be raised by strangers, and possible killed) endeared him to the population, and encouraged the own monarch to raise the standards of education and prosperity for all his subjects, as his own children would benefit from it.
Plus, random selection wasn’t weird enough.
It might be worthwhile to secretly test a few randomly-selected commoners too. Claim they were royalty all along if they pass, otherwise leave as little evidence as possible that the test took place.
SF reference: “Call Him Lord” by Gordon R. Dickson.