In tradition and in poetry, the marriage bed is a place of unity and harmony. The partners each bring to it unselfish love, and each takes away an equal share of pleasure and joy. At its most ecstatic moments, husband and wife are elevated far above worldly cares. Everything else is closed away. This is the ideal. But marriage experts say that such mutual contribution and mutual joy are seldom achieved. Instead one partner or the other dominates the sexual relationship. In the past, it has been the husband who has been dominant and the wife passive. But today there are signs that these roles are being reversed. In a growing number of American homes, marriage counselors report, the wife is taking a commanding role in sexual relationships. It is she who decides the time, the place, the surroundings, and the frequency of the sexual act. It is she who says aye or nay to the intimate questions of sexual technique and mechanics -- not the husband. The whole act is tailored to her pleasure, and not to theirs. Beyond a certain point, of course, no woman can be dominant -- nature has seen to that. But there is little doubt that in many marriages the wife is boss of the marital bed. Of course, there remain many "old-fashioned" marriages in which the husband maintains his supremacy. Yet even in these marriages, psychologists say, wives are asserting themselves more strongly. The meekest, most submissive wife of today is a tiger by her mother's or grandmother's standards. To many experts, this trend was inevitable. They consider it simply a sign of our times. Our society has "emancipated" the woman, giving her new independence and new authority. It is only natural that she assert herself in the sexual role. "The sexual relationship does not exist in a vacuum", declares Dr. Mary Steichen Calderone, medical director of the Planned Parenthood Federation of America and author of the recent book, Release From Sexual Tensions. "It reflects what is going on in other areas of the marriage and in society itself. A world in which wives have taken a more active role is likely to produce sexual relationships in which wives are more self-assertive, too". Yet many psychologists and marriage counselors agree that domination of the sex relationship by one partner or the other can be unhealthy and even dangerous. It can, in fact, wreck a marriage. When a husband is sexually selfish and heedless of his wife's desires, she is cheated of the fulfillment and pleasure nature intended for her. And she begins to regard him as savage, bestial and unworthy. On the other hand, wifely supremacy demeans the husband, saps his self-respect, and robs him of his masculinity. He is a target of ridicule to his wife, and often -- since private affairs rarely remain private -- to the outside world as well. "A marriage can survive almost any kind of stress except an open and direct challenge to the husband's maleness", declares Dr. Calderone. This opinion is supported by one of the nation's leading psychiatrists, Dr. Maurice E. Linden, director of the Mental Health Division of the Philadelphia Department of Public Health. "When the roles of husband and wife are reversed, so that the wife becomes leader and the husband follower", Dr. Linden says, "the effects on their whole relationship, sexual and otherwise, can be disastrous". In one extreme case, cited by a Pittsburgh psychologist, an office worker's wife refused to have sexual relations with her husband unless he bought her the luxuries she demanded. To win her favors, her husband first took an additional job, then desperately began to embezzle from his employer. Caught at last, he was sentenced to prison. While he was in custody his wife divorced him. More typical is the case of a suburban Long Island housewife described by a marriage counselor. This woman repeatedly complained she was "too tired" for marital relations. To please her, her husband assumed some of the domestic chores. Finally, he was cooking, washing dishes, bathing the children, and even ironing -- and still his wife refused to have relations as often as he desired them. One wife, described by a New York psychologist, so dominated her husband that she actually placed their sexual relationship on a schedule, writing it down right between the weekly PTA meetings and the Thursday-night neighborhood card parties. Another put sex on a dollars-and-cents basis. After every money argument, she rebuffed her husband's overtures until the matter was settled in her favor. Experts say the partners in marriages like these can almost be typed. The wife is likely to be young, sophisticated, smart as a whip -- often a girl who has sacrificed a promising career for marriage. She knows the power of the sex urge and how to use it to manipulate her husband. The husband is usually a well-educated professional, preoccupied with his job -- often an organization man whose motto for getting ahead is: "Don't rock the boat". Sometimes this leads to his becoming demandingly dominant in marriage. Hemmed in on the job and unable to assert himself, he uses the sex act so he can be supreme in at least one area. More often, though, he is so accustomed to submitting to authority on the job without argument that he lives by the same rule at home. Some psychologists, in fact, suggest that career-bound husbands often are more to blame for topsy-turvy marriages than their wives. The wife's attempt at control, these psychologists contend, is sometimes merely a pathetic effort to compel her husband to pay as much attention to her as he does to his job. Naturally no woman can ever completely monopolize the sexual initiative. Unless her husband also desires sex, the act cannot be consummated. Generally, however, in such marriages as those cited, the husband is at his wife's mercy. "The pattern", says Dr. Morton Schillinger, psychologist at New York's Lincoln Institute for Psychotherapy, "is for the husband to hover about anxiously and eagerly, virtually trembling in his hope that she will flash him the signal that tonight is the night". No one seriously contends, of course, that the domineering wife is, sexually speaking, a new character in our world. After all, the henpecked husband with his shrewish wife is a comic figure of long standing, in literature and on the stage, as Dr. Schillinger points out. There is no evidence that these Milquetoasts became suddenly emboldened when they crossed the threshhold of the master bedroom. Furthermore, Dr. Calderone says, a certain number of docile, retiring men always have been around. They aren't "frigid" and they aren't homosexual; they're just restrained in all of life. They like to be dominated. One such man once confided to Dr. Theodor Reik, New York psychiatrist, that he preferred to have his wife the sexual aggressor. Asked why, he replied primly: "Because that's no activity for a gentleman". But such cases were, in the past, unusual. Society here and abroad has been built around the dominating male -- even the Bible appears to endorse the concept. Family survival on our own Western frontier, for example, could quite literally depend on a man's strength and ability to bring home the bacon; and the dependent wife seldom questioned his judgment about anything, including the marriage bed. This carried over into the more urbanized late 19th and early 20th centuries, when the man ruled the roost in the best bull-roaring Life With Father manner. In those days, a wife had mighty few rights in the domestic sphere and even fewer in the sexual sphere. "Grandma wasn't expected to like it", Dr. Marion Hilliard, the late Toronto gynecologist, once summed up the attitude of the '90s. Wives of the period shamefacedly thought of themselves as "used" by their husbands -- and, history indicates, they often quite literally were. When was the turning point? When did women begin to assert themselves sexually? Some date it from woman suffrage, others from when women first began to challenge men in the marketplace, still others from the era of the emancipated flapper and bathtub gin. Virtually everyone agrees, however, that the trend toward female sexual aggressiveness was tremendously accelerated with the postwar rush to the suburbs. Left alone while her husband was miles away in the city, the modern wife assumed more and more duties normally reserved for the male. Circumstances gave her almost undisputed sway over child-rearing, money-handling and home maintenance. She found she could cope with all kinds of problems for which she was once considered too helpless. She liked this taste of authority and independence, and, with darkness, was not likely to give it up. "Very few wives", says Dr. Calderone, "who balance the checkbook, fix the car, choose where the family will live and deal with the tradesmen, are suddenly going to become submissive where sex is concerned. A woman who dominates other family affairs will dominate the sexual relationship as well". And an additional factor was helping to make women more sexually self-assertive -- the comparatively recent discovery of the true depths of female desire and response. Marriage manuals and women's magazine articles began to stress the importance of the female climax. They began to describe in detail the woman's capacity for response. In fact, the noted psychologist and sex researcher, Dr. Albert Ellis, has declared flatly that women are "sexually superior" to men. According to Dr. Ellis, the average 20-year-old American woman is capable of far greater sexual arousal than her partner. Not surprisingly, Dr. Ellis says, some recently enlightened wives are out to claim these capabilities. Yet, paradoxically, according to Dr. Maurice Linden, many wives despise their husbands for not standing up to them. An aggressive woman wants a man to demand, not knuckle under. "When the husband becomes passive in the face of his wife's aggressiveness", Dr. Linden says, "the wife, in turn, finds him inadequate. Often she fails to gain sexual satisfaction". One such wife, Dr. Linden says, became disgusted with her weak husband and flurried through a series of extramarital affairs in the hope of finding a stronger man. But her personality was such that each affair lasted only until that lover, too, had been conquered and reduced to passivity. Then the wife bed-hopped to the next on the list. In some cases, however, domination of the sex act by one partner can be temporary, triggered by a passing but urgent emotional need. Thus a man who is butting a stone wall at the office may become unusually aggressive in bed -- the one place he can still be champion. If his on-the-job problems work out, he may return to his old pattern. Sometimes a burst of aggressiveness will sweep over a man -- or his wife -- because he or she feels age creeping up. On the other hand, a husband who always has been vigorous and assertive may suddenly become passive -- asking, psychologists say, for reassurance that his wife still finds him desirable. Or a wife may make sudden demands that she be courted, flattered or coaxed, simply because she needs her ego lifted. In any case, Dr. Calderone remarks, such problems are a couple's own affair, and can't always be measured by a general yardstick. "As long as the couple is in agreement in their approach to sex, it makes little difference if one or the other dominates", Dr. Calderone declares. "The important point is that both be satisfied with the adjustment". Other experts say, however, that if sexual domination by one or the other partner exists for longer than a brief period, it is likely to shake the marriage. And just as domination today often begins with the wife, so the cure generally must lie with the husband. "To get a marriage back where it belongs", comments Dr. Schillinger of the Lincoln Institute, "the husband must take some very basic steps. He must begin, paradoxically, by becoming more selfish. He must become more expressive of his own desires, more demanding and less 'understanding'". Too many husbands, Dr. Schillinger continues, worry about "how well they're doing", and fear that their success depends on some trick or technique of sexual play.