>Reasons for Population Growth. The primary forces driving the growth are sizable nuclear families (five or more children on average) and an average retention rate (Amish children who join the church as young adults) of 85 percent or more. A few outsiders have joined the Amish, but the growth is almost entirely from within the Amish community.
While they have Rumspringa as late teens and can theoretically choose not to get baptized and become adult members, choosing not to means exclusion from the only community they've ever known, into a world they have not been educated to make a living in - particularly, the girls.
