Attitudes toward marriage have changed substantially since World War II. Most obvious was the declining marriage rate, which dropped from 8.5 marriages per 1,000 Finns in 1950 to 5.8, in 1984, a decline great enough to mean a drop also in absolute numbers. In 1950 there were 34,000 marriages, while in 1984 only 28,500 were registered, despite a growth in population of 800,000. An explanation for the decline was that there was an unprecedented number of unmarried couples. Since the late 1960s, the practice of cohabitation had become increasingly common, so much so that by the late 1970s most marriages in urban areas grew out of what Finns called "open unions." In the 1980s, it was estimated that about 8 percent of couples who lived together, approximately 200,000 people, did so without benefit of marriage. Partners of such unions usually married because of the arrival of offspring or the acquisition of property. A result of the frequency of cohabitation was that marriages were postponed, and the average age for marriage, which had been falling, began to rise in the 1970s. By 1982 the average marriage age was 24.8 years for women and 26.8 years for men, several years higher for both sexes than had been true a decade earlier.

The overwhelming majority of Finns did marry, however. About 90 percent of the women had been married by the age of forty, and spinsterhood was rare. A shortage of women in rural regions, however, meant that some farmers were forced into bachelorhood.

While the number of marriages was declining, divorce became more common, increasing 250 percent between 1950 and 1980. In 1952 there were 3,500 divorces. The 1960s saw a steady increase in this rate, which averaged about 5,000 divorces a year. A high of 10,191 was reached in 1979 afterwards the divorce rate stabilized at about 9,500 per year during the first half of the 1980s.

A number of factors caused the increased frequency of divorce. One was that an increasingly secularized society viewed marriage, more often than before, as an arrangement that could be ended if it did not satisfy its partners. Another reason was that a gradually expanding welfare system could manage an ever greater portion of the family's traditional tasks, and it made couples less dependent on the institution of marriage. Government provisions for parental leave, child allowances, child care programs, and much improved health and pension plans meant that the family was no longer essential for the care of children and aged relatives. A further cause for weakened family and marital ties was seen in the unsettling effects of the Great Migration and in the economic transformation Finland experienced during the 1960s and the 1970s. The rupture of established social patterns brought uncertainty and an increased potential for conflict into personal relationships.

Data as of December 1988