This question has not emerged out of nowhere. According to a survey conducted by the Associated Press, infidelity was the reason for divorce in 17% of cases. During the same survey 22% of married men and 14% of married women said that they had extra-marital relations. If this is an official statistic, then what is the real number of cheating spouses? It is well-known that people, especially women, don’t always tell the truth during such surveys. Even if they are assured that the survey is anonymous, not everyone would want to reveal intimate details about their life. Therefore, we can assume that the real percentage of people having extra-marital relations is much higher. Peggy Vaughan, author of "The Monogamy Myth," has come to the same conclusion: "60 percent of men and 40 percent of women will have an extramarital affair in their married life."

Evidently, not every instance of a spouse's affair leads to divorce. However, it leaves its mark on relationships, and very often couples need a family therapist's help to overcome it. Some couples fail to survive such an ordeal and their marriage falls apart. Others are able to manage and get through it, but they never really forget the incident and their life together turns into a series of bitter quarrels.

One of the strange things about infidelity is that in most cases cheaters have no intention of ending their marriage and breaking up their families. In fact, cheaters don’t stop loving their spouses. However, they still go for it. Why? It’s possible that monogamy might not be part of our nature as human beings. People need variety in everything, including their sexual life. After spending a number of years together, marital cohabitation becomes a routine - the spark is gone, replaced by a dull sense of duty.

Scientific research on how humans behave in isolated groups has shown that people tend to become more tense and aggressive. Even the nicest people, the best of friends, and trained professionals start to hate each other after long periods together. The reasons for this phenomenon are still unclear, but the issue remains. What we need to do is take this fact into serious consideration. It’s important for us to understand that being closed off inside the family circle and being limited by one spouse as the only sex-partner can produce an adverse effect: instead of becoming closer, married couples grow farther apart. In order to escape from the routine and predictability of married life, people start looking for exciting adventures outside of the family circle, in the form of adultery. This could be one possible explanation of marital infidelity, but of course far from the only one.

Another common cause of infidelity is job-related. The average person spends about one third of their life at work. This means having constant interaction with colleagues, bosses, partners, clients, etc. Everyone wants these relationships to be enjoyable and friendly, not only for their career, but for other reasons as well, like feeling good about yourself (high self-esteem), avoiding stress, and so on. In addition to simply spending time at the workplace, a working person shares common interests and concerns with colleagues, which is sometimes not the case at home with a spouse. Naturally, such close relations with someone at work can transform into something even closer. But having an affair at work does not necessarily indicate that the person stopped loving their spouse or that their extramarital relationship will ever develop into something more serious.

For example, a daughter will not start loving her mother less after she gets married. She will just be involved in a different kind of relationship with a different person. Or let's take friendship for instance. Sometimes old friends have a deeper and stronger connection with each other than with their sexual partners. Nevertheless, such lasting friendships don’t become grounds for divorce; they don’t hurt a marriage – unlike infidelity.

Of course it’s possible to get used to the routine of married life, to the loss of novelty in relations with your spouse; it’s possible to refrain from making every attractive colleague or acquaintance your sexual partner. Without a doubt, extramarital relations are not unavoidable or even essential. Many couples manage to live without cheating on each other. They are satisfied with their married life and are not looking for "little adventures". But we’re not talking about these lucky couples; we‘re talking about those who yearn for variety in their lives. For such individuals, an interesting question arises: is marital infidelity really that bad for couples? If abstinence from extramarital relations becomes painfully difficult, but necessary to preserve a marriage, is it really worth it?

Let’s go back in time and figure out when the concepts of monogamy and marital infidelity first appeared. Our ancestors from the Stone Age definitely never heard of such things and had sexual encounters with anyone they wanted. They probably entered into temporary conjugal partnerships, like some animals do in our day (as the movie “March of the Penguins” has taught us, these creatures swap partners every year – just enough time to give birth to a baby penguin and nurture it).

The institution of marriage originated in developing societies like Sumer and Ancient Egypt. The idea behind it was to form a social union between two (or more) people, so that they would take care of one another and raise children together. This merger was necessary because it would produce a basic unit (like a cell), out of which the whole society would be built. But at that time marriage was not restricted to one spouse per person, and extra-marital relations were quite common. Pagan societies, for instance, had rituals and holidays when people were allowed to have sex with anybody they wanted. It seems that our predecessors had a better understanding of human nature and tried to live in harmony with it.

In fact, polygamy ("many marriages" in Greek) was the most common form of marriage up until the 5th century A.D., when Saint Augustine introduced monogamy, the Christian model of marriage ("one man, one woman"), in his published letter "The Good of Marriage". In 534 A.D. monogamy was officially declared as the only lawful type of marriage by the Roman Emperor Justinian. The Justinian Code was the basis of European law for a thousand years. Christianity has continued to insist on monogamy as an essential tenet of marriage.

Islam, as opposed to Christianity, allows a man to have more than one wife. But both religions have been very strict about prohibiting extra-marital relations, especially for wives.

It’s difficult to say why this transition took place. One possible reason for condemning extra-marital relations concerns inheritance. In order to exclude all children born outside of the lawful marriage from the list of potential heirs, such relations were purposely labeled as a great sin and warranted punishment. Therefore, all extra-marital relations became forbidden and condemned by society.

Whatever the reasons were back then, we must ask ourselves whether they are still valid in our days. And the answer to that question is clearly a “no”. There is almost nothing left that could count as a good reason to prohibit people from having relations outside of their marriage. Children from such relations can be avoided by using contraceptives. And even if there are such children, their father can easily be identified through DNA analysis. It seems that the main causes for the condemnation of extra-marital relations are either gone completely or have lost their significance.

There used to be another restriction, which (as opposed to marital infidelity) has been successfully eliminated in our society. We’re talking about sex before marriage. Christianity and Islam strictly prohibit such relations between men and women until they get married. This especially concerns women, who are supposed to keep their virginity before the wedding. In our days people do not adhere to this rule anymore. Most newlyweds have a long list of previous sexual partners. And this fact doesn't bother anyone. Society was able to leave this old rule behind. So why are we still clinging to the outdated belief that extra-marital relations are wrong?

There have to be important reasons for this obsession. One of them could be the selfish desire to "own" your other half; another could be the fear of losing your spouse if he or she meets a different, more suitable, partner. Both reasons are based on our egocentricity and are also very much related to our fear of loneliness. In other words, we only think about ourselves and not about what our partner needs. Even though this approach is irrational and works against us, we can’t seem to abandon it. By placing limits on your partner's freedom, you don’t achieve the desired results. It doesn’t help in binding your spouse to you. Moreover, it does exactly the opposite, pushing your loved one away from you - to the point of divorce. Such persistence in maintaining the "no extra-marital relations" rule appears especially foolish when all the other restrictions, the ones upheld by societies for the last thousand and a half years, are gone.

Thus, we are back to our original question: should we continue to consider marital infidelity a great sin? Is marital infidelity a good enough reason to break up a marriage or to damage the relationship you have with your spouse? Maybe it’s time to reconsider our attitude toward this fact of modern life. Maybe we should finally accept the reality that having relations outside of marriage is normal and should be a natural part of our lives.