As devastating experiences go, few can match the emotional havoc following the discovery that your partner is cheating on you.

Atop a suddenly shattered world hover pain and rejection, doubts about your worth and the rupture of trust. For Deanna Stahling, discovery struck in a moment that forever fractured time into Before and After.

Stepping off a plane after a week’s holiday with a friend, she picked up a copy of her local paper. There, in the lifestyle section, was a profile of a female executive whose name Stahling had heard a lot lately – her husband worked with the woman. She’d met her, introduced by her husband at a function. The exec, it was reported, was leaving the company to ethically pursue a relationship with a workmate.

Stahling doesn’t remember the trip home from the airport, but the house was empty and her husband’s stuff was gone. A note on the kitchen table told her to refer any questions to his lawyer.

The next day Stahling and her new counsellor began the search for the source of the sudden defection. Like most therapists, hers subscribed to the presumption that there were dire problems in the relationship.

Recently, however, leading thinkers have begun to abandon this mindset. No one doubts that a straying partner is alone responsible for the decision to engage in infidelity. But a new perspective that puts far more emphasis on situational factors has sparked a revolution in understanding affairs.

● Shifting landscape of love

No one knows for sure just how common affairs actually are. Social desirability and fear of disclosure skew survey responses significantly. In the 2005 Australian Longitudinal Study of Health and Relationships three-quarters of 19,000 respondents viewed affairs in committed relationships as “wrong”. Still, decades of studies show that affairs are as common as celebrity break-ups.

The 2009 Great Australian Sex Census found that 47 per cent of male and 44 per cent of female respondents had been unfaithful and more than 400,000 Australians are paid members of the adulterous dating website Ashley Madison. The latest surveys also reveal a notable shift in the demographics of deception since the Mad Men era. Among those under 45, the rates of infidelity among men and women are converging.

Psychologists and sociologists attribute the development to huge changes in opportunities, particularly the massive movement of women out of the home and into the workplace; studies show that the majority of individuals did the dirty at work. More cash in our hands means we’re less risk-averse, probably because we’re less dependent on a partner for support.

That doesn’t mean that there are no gender differences in affairs. For us, infidelity is driven more by our emotional needs not being met in a relationship, especially when it is not a partnership of equals. For men, infidelity has been more independent of the happily married scenario.

While the landscape of illicit love has been shifting, experts have remained fixed in the belief that affairs occur because something is radically wrong with you and your boyfriend. Make no mistake – most couples stay and want to stay together after a partner has strayed, despite the enormous trauma to the uninvolved person. Yep, 70 per cent of couples choose to rebuild the relationship after infidelity, although they may not quite know how.

While relationship dissatisfaction has been linked with straying, there’s proof that in almost two-thirds of cases, these problems are the effect, not the cause, of cheating. And affairs themselves skew perceptions of the marriage. Once someone has cheated, partners tend to look back on their relationship and see it as having been flawed all along.

Having 100 per cent focus on relationship flaws, reckon the field’s leading thinkers, encourages couples to get psychologically stuck, stewing on the emotional betrayal and playing the blame game. There is no set time period for the hurt and anger that follow a partner’s affair. But for the sake of everyone involved, if you’re the one hurt you’re often rushed into “moving on”, burying distrust and resentments that fester underground or emerge Elin Woods-style, golf club in hand.

● An affair to remember

There are many contributing factors (often nothing to do with the marriage), says psychologist Dr Barry McCarthy. The most common reason: high opportunity. People fall into affairs rather than plan them.”

Common contexts or causes include:

1 | The workplace

Providing large numbers of people with constant contact, common interests, an income to camouflage the costs of socialising outside the office and an ironclad excuse, the workplace is the ideal place for affairs to fester.

A study of more than 4000 adults in the Journal of Family Psychology revealed those who worked but whose spouses didn’t were the most likely to be unfaithful. Opportunity at the office is most ominous when it mixes with uneven power on the home front (think Jesse James and Sandra Bullock).

“But no one profession has a lock on infidelity,” says Dr Kristina Coop Gordon, professor of psychology at the University of Tennessee, US.

2 | Travel frequency

“You’re away from your partner, maybe even missing your mate, and you’re in situations where you’re encountering plenty of people,” Gordon says. “It certainly facilitates one-night stands.”

3| Level of education

As this increases, so does your likelihood of cheating. It may be a marker for more liberal attitudes toward sex. Ditto history of divorce, or divorced parents, especially if either had an affair. Women with a higher education than their husbands have more affairs, perhaps because they are less dependent on a spouse.

4 | Personality differences

Spouses who are comfortable with conflict are less likely to have affairs. Openness is also a characteristic of noncheaters. Associated
with intelligence, creativity, curiosity and insightfulness, openness makes you more satisfied with your relationship and better able to express feelings, including love.

Some researchers believe that openness is essential to commitment and enduring satisfaction in a relationship.

5 | Level of agreeableness (compassionate and cooperative)

Low levels bode poorly for monogamy. More important, however, is whether couples are matched on that trait. Couples who see themselves as more agreeable than their mate believe themselves
to be more giving, feel exploited by their partner, and seek reciprocity in outside relationships.

6 | Self control

Stuff like exposure to alcohol, an exhausting day of travel, doing highly challenging work – raise the risk of infidelity. They disable sexual restraint, psychologists Dr Roy Baumeister and Dr Matthew Gailliot have found. Context aside, another cause of affairs, says Dr McCarthy, is that “people do not feel desired in their marriage, and they want to see if they can be desirable outside it.”

● Hypocrisy or hormones?

The very make-up of your brain contributes to affairs, too, says anthropologist Dr Helen Fisher. She has found, in brain imaging studies, that there are separate neural systems for sex drive, romantic love and attachment, and they can operate independently.

“You can feel deep attachment to a partner but also feel intense romantic love for someone else while feeling a desire for sex with other partners,” she says.

The attachment system, fuelled by neurohormones oxytocin in females and vasopressin in males, drives animals, including humans, to pair-bond to rear their offspring as a team. Both hormones are triggered by orgasm, and both trigger dopamine release in reward regions of the brain. But almost all animals cheat, even when they form pair bonds.

More recently, in a study of more than 500 men by the Karolinska Institute in Sweden, researchers found that variations in a gene that codes for vasopressin receptors in humans influences the very ability to form monogamous relationships.

Men with two copies of a specific gene variant scored lower on a Partner Bonding Scale and reported twice as many marital crises in the past year. Those with two copies of the variant were also twice as likely to be involved in outside relationships and far less likely to have ever been married than those not carrying it.

It’s possible, too, that cheating can serve a positive role in relationships – as a way to gain attention or to signal there are problems in the relationship. A 2010 study by Binghamton University, US, found another payoff – pure, passionate thrill.

● How to move on

One of the great facts of infidelity is that it has such a wildly different emotional impact on each person. The uninvolved partner is deeply traumatised and emotionally distraught over the betrayal, and desperately trying to piece together what happened. The straying partner, often because of deep shame, may get defensive and shut down or blame the other for not moving on, compounding the hurt. One needs to talk about what happened; the other can’t bear to.

Getting on the same track of understanding is the key to recovery, says Dr Gordon, who along with Dr Donald Baucom and Douglas Snyder, professor of psychology at Texas A&M University, US, has sparked the revolution differently in their book, Getting Past the Affair, the first step is for both people to recognise the huge emotional impact on the uninvolved partner.

Dr Gordon and her writing mates have found a powerful device: after encouraging the partners to make no decisions about the future in the immediate aftermath of discovery or disclosure, they ask that the cheated-on partner write a letter to the other describing what the hurt feels like. Awkward, but effective.

“The cheating partner must hear, no matter how discomfiting it is,” says Dr Gordon. “The experience is very intense and usually a turning point. Partners begin to soften towards each other. It’s a demonstration to the injured partner that he or she really matters.”

Then together the couple search for the meaning of the affair. Everything is fair game – attitudes and expectations about the relationship that each person has, conflicts and anything else going on, hidden desires, personal anxieties and insecurities, needs for excitement, the closeness and distance they feel, job demands, work ambience, flirtations, opportunities, the people and pressures around them at home and outside it.

The approach short-circuits the often misguided inclination to focus on The Other Person. From understanding flows forgiveness, which allows the couple to become close again.

● Bringing sexy back

Dr McCarthy gives the revolution in recovery from affairs another twist – re-eroticising the relationship.

“A couple has to develop a new sexual style” that facilitates sexual desire both in and out of the bedroom, he says. The point is to abolish the inclination to compare normal sex with affair sex – a hopeless cause as affair partners don’t have to contend with sick kids or dirty plates, and the illicitness of the liaison intensifies excitement.

Most couples, he says, treat sexuality with neglect – until an affair sets off a crisis. In healthy marriages, sex plays what he deems “a relatively small 15 to 20 per cent part” – but it energises the bond and allows each of you to feel desired and desirable. When couples abandon sex, they wind up draining the entire relationship of its oomph.

“You not only lose the marriage connection but your sense of self,” Dr McCarthy says. “An affair can be an attempt to regain a sense of self.”

So Dr McCarthy recommends reconnecting both emotionally and physically. He focuses on
“non-demand pleasure”. He encourages couples to find a mutually acceptable level of intimacy and come up with their own erotic scenarios.

Six years after her disorienting discovery, Stahling is remarried; her new husband shares her taste for travel and adventure. She understands how her frequent work trips – though they never tempted her to stray – hinted at abandonment for her more anxious ex. And how, under the circumstances, his conversations with a female co-worker could have evolved from a chat to sex... something she’ll never know.

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