The following is an overview of the different forms of infidelity, its causes and effects, and steps for preventing and recovering from infidelity.

Infidelity Defined

As explained by Then (1999), regardless of their religious orientation, most people agree and understand that marriage vows implicitly and explicitly include a promise of “forsaking all others” (p. 4). When this promise is broken, infidelity has occurred in a marriage.

While adultery is more concretely defined as voluntary sexual intercourse between a married man or woman with someone other than his or her spouse, experts disagree on precisely what infidelity entails. There is, however, a growing consensus that infidelity is not limited to sexual unfaithfulness, but that it also occurs when a spouse forms a strong emotional attachment outside of marriage.

According to Lusterman (1998), infidelity can take on several different forms. He defines an affair as an extramarital involvement that takes place over time. Affairs can be emotionally intense but non-sexual relationships, purely sexual involvements with no emotional bond, or can include both sexual and emotional involvement.

The bottom line is that upon establishment of a committed relationship, “if there is a secret sexual and/or romantic involvement outside of the relationship, it is experienced as infidelity” ( Lusterman 1998 )

Statistics on the frequency of adultery or infidelity in the United States are hotly debated and difficult to gauge accurately. Many people provide false responses during studies of infidelity. Also, studies do not tend to take into account a person’s entire life, but focus their questioning only on a person’s current marriage.

So, how many people commit infidelity? According to Peterson (2003), after reviewing 25 studies of infidelity, renowned psychologist and marital researcher Shirley Glass, author of several books on the subject of infidelity, estimates that “25% of wives and 44% of husbands have committed infidelity.” This, however, does not include emotional affairs in which no sexual activity has taken place.

The Consequences of Infidelity

People are most often ''incredibly devastated by their partner's emotional affair,'' says Peggy Vaughan, who has researched infidelity for 20 years, as quoted by Peterson (2003), While many marriages are able to be repaired after infidelity, many other people “separate over it, divorce over it, this breaking of a trust, a bond.''

Glass, in a report for the American Association for Marriage and Family Therapy, reports that the powerful reactions of the betrayed spouse are “similar to post-traumatic stress symptoms of the victims of catastrophic events” and can include stress “physiological hyper-arousal, flashbacks and intrusive images.” Glass explains that other common reactions to the “loss of innocence and shattered trust” include “obsessive pondering of the details of the affair” and continuous monitoring for further signs of betrayal or infidelity.

Glass has observed that the impact of the discovery of infidelity on the betrayed person varies depending on their pre-existing levels of suspicion and trust. She explains, “The most severely traumatized are those who had the greatest trust and were the most unsuspecting.”

It is not just the betrayed spouse that is left reeling, according to Glass. Spouses on both sides of an affair are likely to feel depressed, anxious and grief-stricken upon disclosure of infidelity. The involved spouse may fear that they will never be forgiven while also feeling sadness over the end of the affair.

When infidelity takes place among couples with children, it impacts the entire family. According to Lusterman (1998), children of any age are usually affected profoundly by a parent's infidelity. Children can sense when their parents are troubled, and often know much more about what is going on than parents realize. Children affected by a parent's infidelity often grow up to be unfaithful to their own partners or have difficulty forming and maintaining trusting, intimate relationships.

The Causes of Infidelity

The causes of infidelity are complex and vary greatly from couple to couple. Troubled marriages are not the only ones affected by affairs—happy marriages are at risk as well.

Glass, in a report for the American Association for Marriage and Family, explains that relationships that are particularly vulnerable to infidelity may be hindered by marital problems (such as a lack of communication or fear of intimacy) or life cycle changes (including transition to parenthood). For some, extramarital relationships serve as a way to end dissatisfying marriages. Glass says that more often, however, “the history of a marriage is re-written in order to justify infidelity.” She points out that a forbidden love affair consisting of romantic idealization is not a fair comparison with the “routine familiarity of a long-term marriage.”

Glass cautions that “serial affairs of infidelity may indicate an addiction to sex, love or romance.” As a result of their actions, addicts are often consumed with “feelings of shame and worthlessness.” In contrast, someone who sees extramarital sex as “an entitlement of gender or status” feels free to pursue relationships involving infidelity outside their marriage without the hindrance of guilt.

According to Lusterman (1998), men and women tend to seek different types of fulfillment when turning to infidelity. “Research shows that women are more likely to link sex with love and emotional connection, while men's involvements are more often primarily sexual”

Peterson (2003) outlines the many risk factors that lead to infidelity:

•  “Proximity at the office…. Attractions are a fact of life when men and women work side by side.”

•  “Family patterns.” As indicated by Lusterman parents who cheat can warp their children's view of relationships, producing “sons who betray their wives and daughters who either accept affairs as normal or are unfaithful themselves.”

•  “Biochemical cravings.” The excitement of infidelity can produce changes in brain chemistry that cause the experience to become “almost addictive.”

•  A “biological need for connection can result from ‘severe stress, loss or separation' that often can be traced back to childhood.”

•  “Internet temptations.” Cyber-affairs are more and more common, as the Internet provides “anonymity and convenience” and “escape from the stresses of everyday life.”

•  “Increasing premarital sex.” Before premarital sex became so common, most women were far less comfortable about committing infidelity with anyone but their husband.

•  “Child-centered marriages.” When both parents work, they tend to “give what time they have to the children.” Spouses are then more likely to go outside the marriage and commit infidelity to get the connection and enjoyment they're missing from their partner at home.

Preventing Infidelity

No marriage is completely safe from infidelity. However, couples who want to protect their relationships can take proactive steps to ensure the maintenance of healthy marriages that will leave both partners less open to temptation of infidelity. Peterson (2003) reports the following guidelines:

•  “Stay honest with your partner… Dishonesty and deception cause infidelity to flourish.” Be open and tell your partner when you feel an attraction to someone else or are tempted to stray—you'll be less likely to act on it.

•  “Monitor your marriage.” Pay attention to whether your needs are being met. If they're not, speak up and address it in a constructive manner.

•  “Stay alert for temptations.'' Make a real effort to be aware of when an emotional connection may be forming outside your marriage so that you can stop it from going too far resulting in infidelity.

•  “Don't flirt.” Flirting expresses interest and opens the door to infidelity. Such behavior can nudge relationships beyond platonic boundaries and into infidelity.

•  “Recognize that work can be a danger zone.” Avoid situations that could lead to romance or emotional bonding such as private lunches and regular coffee breaks.

•  “Beware of the lure of the Internet” where “affairs develop quickly” and inhibitions are instantly lowered and infidelity seems innocent.

•  “Keep old flames from re-igniting.” Protect your marriage by avoiding partners from past relationships—or bring your partner along if you do decide to meet with them.

•  “Value the intimacy of your marriage.” Open up to your partner and deepen your relationship so that you won't feel the need to seek intimacy elsewhere, resulting in infidelity.

•  “Make sure your social network supports marriage.” Spend time with other married couples or friends who share your values and respect monogamous relationships.

Overall, infidelity tends to arise when a person's needs are simply not being met within their marriage, leading them to fill those needs elsewhere. When partners understand each other's needs and make an ongoing effort to meet them, infidelity is much less of a threat. Open channels of communication are crucial to expressing unfilled needs and preventing resentment from building over time.