Story highlights Stephanie Coontz: Americans have long presumed that being unmarried, especially as they got older, was not desirable. The fact is, it is now common

Most Americans still marry, although at older ages; new research shows that most never-married individuals lead happy, healthy and helpful lives.

Stephanie Coontz teaches history at The Evergreen State College in Olympia, WA and is director of research at the Council on Contemporary Families. The opinions expressed in this commentary are solely those of the author.

(CNN) It wasn't long ago that being single after a certain age was considered a recipe for lifelong misery. Up until 1970, the average woman married before she was legally old enough to have a drink at her wedding, and the average man married at 23. A woman still single at the ripe old age of 26 was what the Japanese call Christmas Cake -- past her pull date and destined to spoil. A man not married by the end of his 20s was considered irresponsible, if not "deviant."

As late as 1976, 93% of women aged 25 to 29, and 90% of men that age, had already married. By 2014, that was true of only 46% of women and 32% of men in that age group.

The rising age of marriage since the 1980s has worried many. In 1986, Newsweek darkly warned that a woman unmarried at age 35 had only a 5% chance of ever finding "Prince Charming," while a single woman aged 40 was more likely to be killed by a terrorist than to find a husband. According to a chorus of marriage promoters in the 1980s and 1990s, singles were lonely, unhappy, unproductive members of society. Only marriage could turn them into useful citizens, reliable employees, and happy, healthy individuals. Many believe this today.

So it was a radical idea in the 1980s when the Buckeye Singles Council of Ohio called for a National Singles Week to celebrate the lives and achievements of single Americans. It's called Unmarried and Single Americans Week now, and takes place in the third week in September.

But as researcher Bella DePaulo notes, things have changed -- slowly but radically -- for unmarried and single people. New research shows that most never-married individuals, whatever their age, lead happy, healthy and helpful lives. On average, unmarried individuals have a wider network of friends than married couples and visit more frequently with neighbors. They also provide more practical help to parents, other relatives and coworkers than do their married counterparts.

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