a. In Britain 100 years ago the family was less likely to break-up through divorce and single parent families were very rare.
("How Much Has The Family Changed?") argues that compared with the present day,
families in Britain 100 years ago:
According to the 1851 Census, 18% of households were headed by a single parent (mainly through things like the death of a partner, separation and so forth) compared with 9% in 1981.