Theories abound for why Christians and Jews tend to live in small or single-parent families. Brad Wilcox, director of the National Marriage Project at the University of Virginia, said it may be that Christianity, in particular, lends itself to a more individualistic worldview. “Part of the story here is that Christianity and perhaps Judaism have a deeper emphasis on the individual conscience,” said Wilcox. “That may express itself in more nuclear families and single-parent households.”