Goddard's parable of degeneracy was repeated in some of the most popular schoolbooks in America: for generations of readers "The Kallikak Family" offered solid examples to justify familiar Old Testament wisdom about unclean living and inheritance. As the Good Book said "I, the Lord your God, am a jealous God, visiting the iniquity of the fathers on the children, and on the third and fourth generations."
Goddard, Henery Herbert, "The Kallikak Family: A Study of the Heredity of Feeble-Mindedness" (2009). Buck v Bell Documents. Paper 7.