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Open marriage is a form of non-monogamy in which the partners of a dyadic marriage agree that each may engage in extramarital sexual relationships, without this being regarded by them as infidelity, and consider or establish an open relationship despite the implied monogamy of marriage.
Terminology and conceptEdit
The term open marriage originated in sociology and anthropology. Through the 1960s, researchers used "closed marriage" to indicate the practices of communities and cultures where individuals were intended to marry based upon social conventions and proscriptions, and "open marriage" where individuals had the ability to make their own choice of spouse.
Nena O'Neill and George O'Neill changed the meaning of the term with the 1972 publication of their book Open Marriage. The O'Neills describe "open marriage" as a relationship in which each partner has room for personal growth and can individually develop outside friendships, rather than focus obsessively on their couplehood and their family unit (being "closed"). Most of the book describes approaches to revitalizing marriage in areas of trust, role flexibility, communication, identity, and equality. Chapter 16, entitled "Love Without Jealousy", devoted 20 pages to the proposition that an "open marriage" might possibly include some forms of sexuality with other partners. Fueled by frequent appearances of the O'Neills on television and in magazine articles, the redefinition entered popular consciousness, and "open marriage" became a synonym for sexually non-monogamous marriage.
In her 1977 book The Marriage Premise, Nena O'Neill advocated sexual fidelity in a chapter of that name. As she later said, "The whole area of extramarital sex is touchy. I don't think we ever saw it as a concept for the majority, and certainly it has not proved to be."
There are definitional issues that complicate attempts to determine the actual incidence of open marriage.
The meaning of "open marriage" can vary from study to study depending on how the particular researchers have set their selection criteria.
Individuals might claim to have open marriages when their spouses would not agree. Studies and articles that interview individuals without taking their married status into account may not receive accurate information about the actual "open" status of the marriage. Blumstein and Schwartz asked more than 6,000 couples whether or not they had an understanding allowing sex outside their relationship. Interviewed individually, the partners in some couples gave very different responses to this question; the respective replies from one married couple were
Sure we have an understanding. It's 'You do what you want. Never go back to the same one.' See, that's where it's going to screw your mind up, to go back the second time to the same person. (Blumstein & Schwartz, 1983, page 286)
We've never spoken about cheating, but neither of us believe in it. I don't think I'd ever forgive him. I don't think I'd be able to. I don't know. I haven't met up with that situation. (Blumstein & Schwartz, 1983, page 287) 
Couples may have an open marriage in principle, but not engage in extramarital sex. Studies that define open marriage by agreement alone will tend to report a higher incidence than studies that define open marriage by agreement and behavior. Spaniel and Cole found that 7 percent of couples would consider participating in an open marriage, but only 1.7 percent of couples reported having open marriages that actually included extramarital sex. Blumstein and Schwartz found that 15 percent of married couples share an agreement that allows extramarital sex, but only about 24 percent of men and 22 percent of women (or 6 percent and 5 percent of the total, respectively) who had such an agreement actually engaged in extramarital sex during the prior year. 
Researchers have regularly applied "open marriage" in overly narrow terms. For example, Hunt defined open marriage specifically as swinging couples who meet with other swinging couples to swap mates.
Open marriage is usually defined in terms of legally married, opposite-sex partners. Data collected from these kinds of open marriages may not generalize to other kinds of open relationships. For example, cohabiting couples tend to show higher levels of involvement in extra-relational intimacy compared to married couples. Gay male couples show very high levels of open relationships compared to straight couples.
The impact of open marriage on relationships varies across couples. Some couples report high levels of marital satisfaction and have long-lasting open marriages. Other couples drop out of the open marriage lifestyle and return to sexual monogamy. These couples may continue to believe open marriage is a valid way of life, just not for them.
The extent to which open marriage actually contributes to divorce remains uncertain. Blumstein and Schwartz note a slightly higher risk of divorce among couples who engage in extramarital sex, even if the couples agree to allow extramarital sex. However, Rubin and Adams did not observe any significant difference in the risk of divorce for couples in open marriages and couples in sexually monogamous marriages.
A 1981 study concluded that around 80 percent of people in open marriages experienced jealousy over their extramarital relationships. Couples in open marriages experienced as much or more jealousy than people in sexually monogamous marriages.
Martin Weinberg, Colin J. Williams, and Douglas Pryor found that 77 percent of bisexuals in sexually open relationships had partners who experienced jealousy at some point. The largest group, at 46.2 percent, said their partners experienced only a little jealousy. The remaining 30.8 percent said their partners experienced moderate to extreme jealousy. (These findings may not generalize to heterosexual married couples, as most of subjects were not married.) In addition, bisexuals are often more jealous of outside partners of their own sex. "Primary partners were reportedly more jealous of an 'outside' partner of their own sex -- for example, a man whose primary partner was a woman would say she was more jealous of his relationships with other women. The logic that underlies this was that a person of the same sex as themselves could meet similar needs and thus replace them. A person of the opposite sex would not compete in this way, satisfying a different set of needs for their partner." (Weinberg, Williams, & Pryor, 1995, page 108)
People who experience normal jealousy have at least nine strategies for coping with jealousy. The problem-solving strategies include: improving the primary relationship, interfering with the rival relationship, demanding commitment, and self-assessment. The emotion-focused strategies include: derogation of partner or rival, developing alternatives, denial/avoidance, support/catharsis, and appraisal challenge. These strategies are related to emotion regulation, conflict management, and cognitive change.
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Couples involved in open marriages or relationships typically adopt a set of ground rules to guide their activities.
Ground rules in relationships allow partners to coordinate their behaviors, so they achieve shared goals with fewer conflicts. Some ground rules are universal in the sense that they apply to virtually all relationships in a particular culture. Other ground rules apply to particular kinds of relationships, such as friendships or marriages. Still other ground rules are designed to manage romantic rivalry and jealousy. The ground rules adopted by sexually monogamous couples tend to prevent behaviors that are viewed by the participants as acts of infidelity.
The ground rules adopted by sexually open couples tend to prohibit behaviors that provoke jealousy or sexual health concerns. Partners may change the ground rules of their relationships over time. One example of a changing ground rule includes where a married couple decides to separate. Without divorcing, they are still legally married. However, they may choose to continue cohabitation.
Ground rules in open relationships may include, for example: that partners disclose who they have sex with; that they limit their involvement with others (for example, to dating or physical intimacy but not relationships); or that they not become involved with certain people (such as the other partner's friends or coworkers).
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Couples in open marriages may prefer different kinds of extramarital relationships. Couples who prefer extramarital relationships emphasizing love and emotional involvement have a polyamorous style of open marriage. Couples who prefer extramarital relationships emphasizing sexual gratification and recreational friendships have a swinging style of open marriage. These distinctions may depend on psychological factors such as sociosexuality and may contribute to the formation of separate Polyamory and Swinging communities. Despite their distinctions, however, all open marriages share common issues: the lack of social acceptance, the need to maintain the health of their relationship and avoid neglect, and the need to manage jealous rivalry.
Many open couples establish rules that forbid emotional attachment, extramarital children, extramarital sex in the marital bed, extramarital sex with those known to both partners, or extramarital sex without the use of barrier contraception.
Some open marriages are one-sided. Some situations giving rise to this are where the libidos of partners differ greatly, or illness renders one partner incapable of, or no longer desiring, sex. The couple may remain together while one partner seeks out sexual gratification as they sees fit. The difference between these situations and a cheating situation is that both partners in the marriage are aware of, and agree to the arrangement.
Types of openness: from "polyamory style" to "swinging style"Edit
Extramarital relationships vary in terms of the degree of sexual involvement desired and the degree of emotional involvement desired. Presented with the potentiality of non-monogamous intimacy, a given individual might be motivated more either by the desire for multiple sexual partners or a wider erotic experience than offered by monogamy, or by the desire for multiple others with whom to form an emotional or familial bond.
Polyamory is motivated by a desire to expand love by developing emotionally involved relationships with extramarital partners. Swinging is motivated by a desire for physical gratification by engaging in sexual activities with extramarital partners. The distinction between polyamory and swinging applies to open marriages. Delineation of polyamory and swinging has appeared in academic literature, popular media, and Web sites devoted respectively to polyamory and to swinging. (The swing sites prefer to frame the distinction more along Gould's "utopic swingers" and "recreational swingers".)
A polyamorous style of open marriage emphasizes the expansion of loving relationships by developing emotional attachments to extramarital partners. A swinging style of open marriage emphasizes physical gratification by engaging in recreational sex with extramarital partners.
The preference for a polyamorous versus a swinging style of open marriage may depend on many psychological factors. One factor may be sociosexuality, an individual's willingness to engage in sexual behavior without having emotional ties to the sex partner. Individuals who are very willing to engage in sexual behavior without emotional ties are said to have unrestricted sociosexuality. Individuals who are very unwilling to engage in sexual behavior without emotional ties are said to have restricted sociosexuality. Individuals can vary along a continuum from unrestricted to restricted sociosexuality.
Couples with different styles of open marriage tend to self-segregate in order to find others who share similar philosophies and interests, which has likely contributed to the development of separate polyamory and swinging communities. These offer informational resources and support, even if a given couple in an open marriage cannot see themselves joining either community. Some couples may not have a strong preference for either style of open marriage, feeling equally at home either community.
The partners within a couple may differ in their respective preferences. One partner may prefer a polyamorous style of open marriage and participate in the Polyamory community, while the other partner may prefer a swinging style of open marriage and participate in the swinging community. Variations in couple preferences and individual preferences thus can result in overlap between the polyamory and swinging communities.
Evidence of disapprovalEdit
Surveys show consistently high disapproval of extramarital sex. Hunt briefly mentions three surveys conducted in the 1960s in which large majorities disapproved of extramarital sex under any conditions (see page 255 of his book Sexual Behavior in the 1970s). More recent surveys show that 75–85 percent of adults in the United States disapprove of extramarital sex. Similar levels of disapproval are observed in other Western societies. Widmer, Treas, and Newcomb surveyed over 33,500 people in 24 nations and found 85 percent of people believed extramarital sex was "always" or "nearly always" wrong. However, disapproval of extramarital sex does not specifically imply disapproval of open marriage, since open marriage does not always involve extramarital sex.
Much of that disapproval is attributed to "religious and moral reasons."
A few studies have shown more direct disapproval of open marriage. In a national study of several hundred women and men, Hunt reported that around 75 percent of women and over 60 percent of men agreed with the statement "Mate-swapping is wrong." A study of several hundred men and women living in the midwestern United States found that 93 percent would not consider participating in swinging. Yet another study asked 111 college women about various forms of marriage and family. These young women viewed open marriage as one of the least desirable forms of marriage, with 94 percent saying they would never participate in a marriage where the man has a right to sex outside the marriage, and 91 percent saying they would never participate in a marriage where the woman has a right to sex outside the marriage.
The evidence thus shows strong social disapproval of open marriage. Very large majorities of people in Western societies disapprove of extramarital sex in general, and substantial majorities feel open marriage is wrong even when the spouses agree to it. Nine out of ten people say they would never consider open marriage for themselves.
Some critics object to open marriages on the ground that open marriages violate religious principles.
Generally, non-monogamous people tend not to be very religious. A 1998 review observed that, across the various studies, most swingers (approximately two-thirds) claimed to have no religious affiliation.
Engaging in sex with a greater number of partners increases risk of contracting sexually transmitted diseases. A 1985 study found that 33 percent of male swingers and 10 percent of female swingers claimed to actively fear this risk. In another study, sexually transmitted diseases topped the list of disadvantages of swinging, and 58 percent of swingers expressed some fear of HIV/AIDS. Some couples have decided to drop out of open marriage lifestyles and become sexually monogamous in response to HIV/AIDS.
The risk of sexually transmitted diseases can be greatly reduced by practicing safer sex. However, the percentage of people in open marriages who practice safer sex remains disputed. Anecdotal observations range from claiming no one at a swing event practiced safer sex to claiming everyone at an event practiced safer sex. A survey of swingers found that "Over 62% said that they had changed their behaviors because of the AIDS scare. The two most frequently mentioned changes were being more selective with whom they swung and practicing safer sex (e.g., using condoms). Almost 7% said they had quit swinging because of the AIDS epidemic. Finally, one third said that they had not changed any of their habits, and, of these respondents, more than a third said nothing, not even AIDS, would get them to change."
Although a majority of swingers reported changing their behaviors in response to HIV/AIDS, some chose to become more selective in choosing partners rather than adopting safer sex practices. Greater selectivity in choosing partners is not a reliable means of reducing the spread of HIV/AIDS. Many people are not aware they are infected, and no outwards signs of infection may be visible. One psychological study suggests people may not be particularly good at detecting lies about HIV status. Remarkably, one-third of swingers flatly rejected the idea of changing their behaviors in response to HIV/AIDS. These finding suggest people involved in open marriages may indeed be at somewhat greater risk of sexually transmitted diseases, including HIV/AIDS.
These concerns do not apply to open marriage alone, which would affect only 1 to 6 percent of the married population.. Though most Westerners claim to be monogamous, a it is more precise to say that they are serially monogamous.
Several authors consider open marriages to be psychologically damaging. They claim sexual non-monogamy proves too difficult for most couples to manage, and their relationships suffer as a consequence.
These authors contend that sexual non-monogamy provokes jealousy in couples. This disrupts couples' sense of security in their relationships and interferes with their sense of intimacy. Consequently, these authors view open marriage as a "failed" lifestyle.
In fact, the impact of open marriage varies across couples. Some couples report high levels of satisfaction and enjoy long-lasting open marriages. Other couples drop out of the open marriage lifestyle and return to sexual monogamy. These couples may continue to view open marriage as a valid lifestyle for others, but not for themselves. Still other couples experience problems and report that open marriage contributed to their divorces. Investigators do not yet know why couples respond to open marriages differently.
"Openly non-monogamous married and cohabiting couples often feel they are thought of as bizarre or immoral by the rest of their world. They have to work out their sex lives in opposition to the rest of society. They may have an understanding with each other, but they usually keep it secret from family, friends, and people at work." (Blumstein & Schwartz, 1983, pages 294–295).
Keeping their lifestyles secret reduces the amount of social support available to people in open marriages. Numerous studies have shown that social support carries many psychological and physical health benefits. Thus, strong social disapproval of open marriage may lead to a loss of psychological and health benefits for couples in open marriages.
Whether an open marriage is with the knowledge, consent or encouragement of the partners, the practice may still be regarded as extramarital sex or adultery, which may be illegal in some jurisdictions.
This section needs to be updated.(May 2018)
The percentage of men and women actively involved in open marriages may be determined from data reported in 1983 by Blumstein and Schwartz. Out of 3,498 married men, 903 had an agreement with their spouses allowing extramarital sex; out of these 903 married men with an agreement allowing extramarital sex, 24 percent (or 217 men) actually engaged in extramarital sex during the previous year. This means about 6 percent (i.e., 217 / 3498) of married men were actively involved in open marriages during the previous year. The number is only slightly less for married women. Out of 3,520 married women, 801 had an agreement with their spouses allowing extramarital sex; out of these 801 married women with an agreement allowing extramarital sex, 22 percent (or 176 women) actually engaged in extramarital sex during the previous year. This means about 5 percent (i.e., 176 / 3520) of married women were actively involved in open marriages during the previous year.
The estimates based on the Blumstein and Schwartz study are slightly higher than estimates provided by other researchers. Hunt, based on interviews from a 1974 national study of sexual behavior, estimated that 2–4 percent of the married population is involved in open marriages. Bartell (1971) estimated that 2 percent of the married population is involved in open marriages. The lowest estimate comes from a study conducted by Spanier and Cole (1975) of several hundred people living in the midwestern United States. This study found just 1.7 percent of married people involved in open marriages.
Following the 1972 publication of Open Marriage, the popular media expressed a belief that open marriages were on the rise. This belief turned out to be incorrect. Comparing data from the earlier Kinsey studies with his own data, Hunt concluded the incidence of extramarital sex had remained about the same for many years.
"Among wives under 25, however, there is a very large increase, but even this has only brought the incidence of extramarital behavior for these young women close to—but not yet on par with—the incidence of extramarital behavior among under-25 husbands." (Hunt, 1974, page 254)
Hunt attributed the mistaken impression of increasing open marriages to a barrage of books, articles, and television shows dealing with the topic. He also notes that speculative comments about increases in open marriage would sometimes be repeated often enough that people cited them as evidence.
Nearly twenty years later (1993), in a national study of sexual behavior, Janus and Janus likewise denied that open marriages were on the rise. In fact, they suggested the number of open marriages may have declined:
"Despite popularization in a book of that title in the early 1970s, open marriage has never become as prevalent as nonconsensual extramarital activities, and its popularity seems to be waning even further today." (Janus & Janus, 1993, pages 197–198)
Open marriage remains a controversial topic capable of generating much media interest. A large amount of media interest can mislead people into thinking the incidence of open marriage is on the rise. Conversely, media attention given to the marriage movement can mislead people into thinking the incidence of open marriage is declining. Weiss notes:
"Despite the vast attention given to these alternative lifestyles in the 1970s, and despite the more recent claims that Americans are 'returning to traditional models of monogamous marriage,' there is no scientific basis for concluding that these patterns increased in popularity earlier or that they have become less common in the 1980s and 1990s." (Weiss, 1997) 
Investigators have found no reliable evidence that open marriage has either increased or decreased substantially over the last two generations.
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