For hundreds of years, marital advice books have been written for women rather than men, because women were responsible for making a marriage work. And over all that time, their advice to women could be summed up in a single word: submit.
Church officials in the 12th century declared that only God could own a woman's soul, but her husband had a leasehold over her body and she could not deny him its use. The tale of "Patient Griselda" was a staple of the marital advice industry in the 14th century. Its moral, one author explained, was that if a husband makes outrageous demands, do not refuse one's "ruler," for "greater good cometh by obeying." In the 16th century, ministers rebuked wives who used endearing nicknames for their husbands, because such familiarity undermined a man's authority.
A woman should be trained from girlhood for "docility," because "she will never be free to set her own opinion" above her husband's, wrote 18th-century philosopher Jean-Jacques Rousseau. Indeed, a wife should "place herself, instead of running the risk of being placed, in a secondary position," recommended one of the most widely read advice experts in 19th-century Britain and America, Sarah Ellis.
Beginning in the 1920s, professional psychologists replaced physicians and ministers as advice givers, but otherwise little changed. The premier marital therapy association of the 1950s, the Institute of Family Relations, handled the popular Ladies' Home Journal feature, "Can This Marriage Be Saved?" The answer was almost always yes, but only if, after counseling, the wife allowed her husband "to feel, as she now feels, that he is the head of the family."
The "rules" for a successful marriage in the 1950s were clear-cut - and still directed at women. Marry early. Say no to sex before marriage, but afterwards, never say no to anything again. Act dependent and a little dumb. One prominent 1950s marriage therapist told wives to express an interest in their husband's work, but never act as though they were truly knowledgeable about it. If your marriage is in trouble, "pretend ineptitude" at tasks like balancing the checkbook and invent little tasks to make your husband feel needed, such as fraying a lamp cord to produce a short, so he can step in and rescue you.
Today we may find such advice appalling, but back then it actually worked. Until the end of the 1950s, girls with the most conventional views about women's roles and the least economic independence were the ones who got and stayed married. A woman who postponed marriage to pursue a college degree might never marry at all, and if she did she had a much higher risk of divorce.
But this rule, and most others like it, no longer applies. For females born since 1960, college graduates and women with higher earnings are more likely to marry than women with less education and lower wages. Men are much more likely than in the past to want a partner who is equally educated. And studies show that marriages in which wives are not afraid to ask their husbands to change and where men respond favorably to such requests have the greatest chance of turning into long, happy relationships.
Yet many marriage-advice books still claim that the secret to a successful marriage is for women to "surrender" to their husbands' traditional views about gender roles. But recent research shows that this is a bad idea. Today men with traditional ideas about male and female roles are more likely to divorce than men with non-traditional views. It's particularly bad advice to tell women to play games to catch a man, because women tend to grow more discontented with their marriages over time, while men grow more content, even if they initially resisted pressure to change their behavior.
I once asked my students to review the marital advice books in our town's bookstores and determine how many were based on actual research data and peer-reviewed studies. Only 34 percent - one in three - passed that test. One student went a step further and researched the family history of marital-advice experts. Half of them had been through a divorce, a track record no better than the nonexperts!
Of course, there are many well-researched books that provide tested methods for improving a marriage. And divorced experts may even bring a special insight to their work because they've personally experienced how a marriage can go wrong. But the role of marriage in society and personal life has changed more in the past 30 years than in the previous 3,000, primarily because of the new opportunities for women to live independent lives. In consequence, everything we used to think we knew about who marries and how marriage works - and why it doesn't work - is changing.
Marriage was a lot more stable when women had to give in to everything their husbands wanted. But it was also less satisfying, not just for women but for many men who never quite understood why their wives were so unhappy or withdrawn.
Over the past century, a good marriage has steadily become fairer, more fulfilling, and better at fostering the well-being of adults and children than ever before in history. At the same time, an unsatisfactory marriage has become less bearable and more brittle. These two seemingly contradictory changes stem from the same source - the breakdown of husbands' legal domination over wives and of women's economic dependence on men.
Today, marriage takes more time, more love, more work, and more daily negotiation - from both partners, not just the wife - than it did in the past. There is no magic formula, weekend encounter, or set of "rules" that can bypass the hard work it takes to make a marriage succeed. The bad news is that if negotiations break down, there are few constraints forcing unhappy partners to stay together. Yet. if they could speak, a lot of couples who lived in the "old days" would tell you that this is also the good news.
• Stephanie Coontz is the author of Marriage, A History: From Obedience to Intimacy, or How Love Conquered Marriage (Viking, 2005).