In a harsh environment where humans barely survive, ritual cannibalism would stay just long enough until someone’s protein mis-folded and the stupid practice got the well deserved handicap. You need some sort of tropical paradise isolated from competition to sustain Kuru-afflicted population for any time.
Speculating is the key word.
In a harsh environment where humans barely survive, ritual cannibalism would stay just long enough until someone’s protein mis-folded and the stupid practice got the well deserved handicap. You need some sort of tropical paradise isolated from competition to sustain Kuru-afflicted population for any time.
There are plenty of highly-competitive, agricultural civilizations in the tropics.