Earlier this year, the death of Sr Frances Carr left only two remaining members of her Shaker religious community, which was established in Maine in 1783. The Shakers being bound to celibacy, renewal by numbers has been a challenge. This won’t be a problem for another of North America’s odd religious offshoots: the fundamentalist Mormons of Rockland in Utah have made it their mission to produce as many children as possible, with every man in the community permitted to take up to four wives. As the first episode of Three Wives, One Husband made clear (23 March), it has achieved its objective with impressive speed: families in Rockland routinely have up to 20 children: the two that feature in this programme have 17 and 11, respectively, and the men haven’t even reached their wife quota yet. Rockland’s founder, the preacher Robert Dean Foster, had 38 children by four wives and 85 grandchildren.