In the UK a study in 1993 correlated a 10-fold increase in reported crime between 1955 and 1991 with growth of cohabitation, divorce and births outside marriage. The proportion of women in the UK who had cohabited with their future husbands prior to marriage rose from approximately 5% in the mid-1960s to over 50% in 1991. It is expected to rise to 80% by 2000. In 1993, 30% of children were born outside marriage, with about half of these to cohabiting parents.
Cohabitation as a way of life is practised by certain racial groups; in the West Indies, though not so much among Latin Americans, it is customary for couples to change partners, resulting in the children of such unions being deprived of a stable family environment and suffering from loss of identity. In an extended family situation, such children may be cared for by relatives; but where the practice is continued after immigration to an industrialized country, the children are often abandoned.
2. Armed with these principles, some men go so far as to concoct new species of unions, suited, as they say, to the present temper of men and the times, which various new forms of matrimony they presume to label "temporary," "experimental," and "companionate." These offer all the indulgence of matrimony and its rights without, however, the indissoluble bond, and without offspring, unless later the parties alter their cohabitation into a matrimony in the full sense of the law. Indeed there are some who desire and insist that these practices be legitimatized by the law or, at least, excused by their general acceptance among the people. They do not seem even to suspect that these proposals partake of nothing of the modern "culture" in which they glory so much, but are simply hateful abominations which beyond all question reduce our truly cultured nations to the barbarous standards of savage peoples. (Papal Encyclical, Casti Connubii, 31 December 1930).
3. Researchers claim that married couples generally enjoy better health and greater wealth than do couples that live together without marrying. Married couples invest more in the future, both materially and emotionally, because they feel a stronger lifelong commitment to the relationship.