George B. Louis Arner, Consanguineous Marriages in the American Population
“ The best writers of the present day no longer recognize consanguinity as a cause per se, of idiocy. The heredity of neuroses, however, is so strongly established that few would dispute the proposition that where the morbidity is inherited through both parents it appears more frequently and in a more marked degree than where one parent is entirely free from taint. This is what occurs when a consanguineous marriage takes place between descendants of a neurotic family. ”
