In the 1930s, The Settled Science was “eugenics”–the art of breeding human beings like livestock until all flaws and defects were bred out of the gene pool and you had nobody left but supermen and superwomen. Anyone who questioned it was laughed out of the room.
Was Edgar Rice Burroughs, the creator of Tarzan, buying it?
The internal evidence in his writings strongly suggests he did buy into this stuff… Except for the fact that he knowingly made the entire Venusian system of super-science to rest on a joke. The whole basis for the Venusians’ all-wise, all-right all the time science is… a joke!
So maybe ERB was having a laugh on everybody. I wouldn’t put it past him.