Love and intimacy are at the core of humanity. The need for each is hardwired in all of us – dreamers, doers, madmen and the perfectly sane. But love and intimacy can also bring us to our knees, leading us into breathtaking emptiness, sadness and despair. Who hasn’t been there?

Without a doubt, one of the worst parts of love, perhaps one of the worst parts of being human, is finding that the person we love might be falling in love (or in-like-a-lot) with somebody else.

Infidelity occurs worldwide and across many different cultures. It’s been happening throughout the ages, so in terms of human behaviour, it seems to be a classic, despite that we all condemn it.

Infidelity: How Does it Happen?

The are many reasons people stray from the arms of a long-term intimate partner and into the arms of another. Sometimes an affair is the externally visible break of something that has been fractured on the inside for a while. Sometimes it has nothing to do with the marriage at all. According to biological anthropologist Helen Fisher, 56% of men and 34% of women who strayed from their long-term relationship rated those relationships as ‘happy’ or ‘very happy’.

So why then?

There are a host of reasons that people turn their attention from a long-term relationship to one with somebody new – and they are reasons, not excuses. Regardless of whether an explanation can be offered by biology, personality, genetics or evolution, infidelity is always a choice.

The more we can understand about what drives a behaviour, the more we can draw a bold heavy underline between it and the rest of forever and move forwards. If you’re the one who was hurt, know that this may have had nothing to do with you, or your partner’s satisfaction with the relationship.

Having said that, it’s important to look at your relationship with an open heart and an open mind. Is there any way you may have contributed to the breaks? Not that you anyone deserves to be on the end of the pain that comes with infidelity, but if your partner has been lonely, felt pushed aside by you or had his or her needs in the relationship ignored or overlooked, then he or she didn’t deserve that either.

If you’ve been attentive, loving and open – and it’s important to be honest – then none of this will make sense. It probably never will, but at some point, if you want to stay in the relationship you will have to forgive. That doesn’t mean accepting what happened. What it means is understanding it enough to stop the anger and hurt from having power over you. People make mistakes. Sometimes they are bad ones. So bad that you might be in pieces for a while because of them. But know that your relationship can survive – if you both want it to.

If you are the one who has turned your affection to someone outside your relationship, it’s important to decide whether or not you want to fight for the relationship you began with. If you do, it’s important to own the mess. Take responsibility, be patient, be accountable, be honest and above all else, be loving – so loving. Be loving through the anger, the hurt, the fear and the raw jealousy that will come your way, until you both find your way through.

Now for the reasons. Here’s what we know:

1. Brain Architecture

   We have three brain systems that are designed to drive us to seek out and maintain intimate connections.

   The first is the sex drive and it’s designed to get us out there looking for a potential other. From an evolutionary perspective, this is important for survival of the species.

   The second is attraction, or romantic love, and it’s the longing we feel to be with one particular person. Powerful neurochemicals – dopamine, norepinephrine and serotonin – surge through the body, igniting the euphoric feelings that come with falling in love and focussing energy on that on that one special person. Serotonin is involved in mood regulation, social behavior, appetite, digestion, sleep, memory and sexual desire and function, so there is likely to be sleeplessness, loss of appetite and increased passion. The area of the brain involved here is the same area that lights up when a cocaine addict is injected with cocaine. It’s by no beautiful accident then, that falling in love brings with it a giddying, addictive high. 

   The third brain system is attachment. At this point, the body starts to develop a tolerance to the euphoria of the attraction phase. Endorphins (the feel-good hormones) and the hormones vasopressin and oxytocin wash through the body, bringing about the feelings of security, calmness and well-being that come with an enduring relationship.

   Okay. So how does this relate to an affair?

   Over time in a relationship, dopamine – the neurochemical that drives feelings of pleasure and motivation – will diminish significantly if things aren’t kept interesting and fresh. When dopamine stays too low for too long, the instinctive push to connect and feel pleasure will gain momentum and the pull of sexual desire, attraction and attachment will strengthen.

   Dopamine will surge in response to something novel, so when there is someone the person is drawn to outside the marriage, continued exposure to that new, novel person will cause dopamine, the pleasure hormone, to constantly rush the body. This will bring about the euphoria of falling in love. When that person isn’t close, serotonin will drop, bringing sadness, emptiness and the push to seek that person out and be with them. Serotonin is also involved in impulse control, so when it’s at a low, people are more likely to act on impulse and do things they might not otherwise do.

   Adrenaline and norepinephrine also rush the body, amping up the feelings of euphoria and excitement that come with the possibility of connecting intimately with another. These neurochemicals are behind the lines we’ve all heard, and possibly said – ‘He makes my heart race,’ or ‘She takes my breath away’. They are clichés for a reason. Quite literally, because of the neurochemicals that are surging through the body, this is exactly how it feels to fall for someone. 

2. The Relationship

   Not all affairs are a reflection of relationship dissatisfaction, but some are. The relationship reasons that drive people to have affairs are:

   •  general unhappiness and dissatisfaction within the long-term relationship;

   • personal needs going unfulfilled;

   •  significantly diminished or absent feelings of love for partner;

   •  frequency and quality of sex;

   •  lack of emotional support;

   •  lack of appreciation;

   •  lack of connection between the couple;

   •  the couple share more negative interactions and fewer positive interactions;

   •  less personal need for the relationship, so more ready to let it go;

   •  fewer shared resources between the couple that will be lost and missed if the relationship ends (friendships, possessions, connections);

   •  husbands who strayed were less satisfied with the relationship before marriage. Wives not so much.

3. Personality

   People who have affairs tend to be more open to new experiences and extroverted than their partners and more easily bored. Remember though – this is a tendency, not a given.

4. Biological

   Depression

Depression is a risk factor for having an affair. Of course, that doesn’t mean that just because someone has depression, he or she will have an affair – not at all.

Interestingly, the decreased serotonin that is characteristic of the attraction phase also happens during depression. It’s perhaps not surprising then, that depression is one of the risk factors of an affair. In this context, infidelity can be understood as an unwitting attempt to self-medicate and overcome the effects of low serotonin. When the potential for an intimate connection becomes realised, the constant surges of neurochemicals counter the effects of low serotonin by nurturing feelings of euphoria, happiness and pleasure.

Helen Fisher has suggested that the long-term use of anti-depressants that raise serotonin can potentially affect other brain systems associated with love and intimacy. Antidepressants increase serotonin, which depresses the dopamine circuit. Dopamine is associated with the feelings that come with romantic love. Compounding this is the potential of antidepressants to smother the sex drive and deprive the body (and the relationship) of the neurochemicals associated with attachment that surge the body during orgasm.

The 334 Allele

The research on biology and infidelity is compelling. (But even in light of this, infidelity cannot be blamed on biology).  Research has found that men carrying the 334 allele in the region of the vasopressin systems scored significantly lower on a questionnaire that measured how attached they felt to their partner. Those who carried two of the alleles showed less feelings of attachment than those who carried only one. They were also about twice as likely to have had a crisis in their marriage during the past year. 

Before you kiss me, do we have genes in common?

In another classic (and pretty gross) experiment, women smelled the sweaty t-shirts of men and chose the ones they thought were the sexiest. Results showed that they selected the shirts of men with different genes in a specific part of the immune system. In a subsequent study, women who were married to men with similar genes in this part of the immune system were more likely to stray outside their relationship. The more genes a woman had in common with her spouse, the more affairs she’d had. From an evolutionary perspective, this can be understood as a way to minimise complications in pregnancy and fertility.

After the Affair: Dealing with Infidelity

Relationships can certainly heal from infidelity but this will depend on the love that remains, the honesty with which the breakages are explored, understood and owned, and the capacity of each to reconnect in light of the betrayal. 

1. End the affair properly. 

   Given what we know about the role of neurochemicals in reinforcing attraction and desire, it’s critical that the person involved in the affair cuts communication with the outside person if the relationship is going to be given a fighting chance.

2. Put the affair in context. 

   The most important step to coming back from the brink of betrayal is to understand the affair within the context of the relationship, rather than as one person’s personal failure. It would be easy, and understandably very tempting, to pile shame and blame on to the person who had the affair, but this will squander any opportunity to address any deeper problems that contributed to the fracturing of the relationship. A couple can let each other down in plenty of ways. An affair is just one of them. Other ways include neglect, indifference, withholding of sex, failure to emotionally connect, and constantly overlooking the needs and wants of the other. It’s important to look at intimacy, communication, expectations, need fulfilment and the way conflict or competing needs are handled in the relationship.

3. Understand how each other is feeling.

   It’s important for both people to understand and accept what the other may be feeling in response to the revelation of the affair:

   •  At different times, the person who has been betrayed is likely to feel insecure, jealous, angry, deeply sad, unable to trust and anxious. It’s likely there will be a tendency to obsess over details of the affair and hypervigilance around anything that might signal continued contact with the person the affair was with or clues the affair isn’t over. And then there’s the mental images.

   •  The person who had the affair is likely to feel shame, regret, fear of continued ‘punishment’ over the affair, anger, grief for the person they’ve had to let go of, resentment, emptiness.

4. Be accountable. Every second, every minute, every hour – and don’t argue about this one.

   If you’re the person who has had the affair it’s critical that you remain completely accountable, sometimes perhaps ridiculously so, until the trust is rebuilt. This might take a while but it’s important if you want to rebuild your relationship. Be where you say you’re going to be, when you say you’re going to be, and if your partner rings, answer. If he or she texts, text back – always, no matter what. Rebuilding trust is key and that’s not going to happen without a massive display of commitment to the task.

5. At some point, you’ll have to forgive.

   If you’re the one who has been hurt, at first there’ll be two types of days – bad ones and really bad ones. You’ll feel hurt, angry, sad beyond words and some days you’ll feel like you just can’t breathe. No doubt your partner will wear this for a while, and everything else that’s in you that has to come out. Eventually though, if you’ve decided to stay in the relationship you will have to make the decision to stop punishing your partner. He or she will already be feeling enormous shame. Go your hardest for a while, but then stop. Your relationship will depend on it. One way to do this is to be willing to honestly explore and own any way you may have contributed to the fall of the relationship.

6. You’ve made a mistake. Don’t fight the response.

   If you’re the one who has had the affair, understand that your partner will be hurt, angry, in love with you, in hate with you, miss you, never want to see you again, won’t want to be without you – and sometimes this will turn so quickly you won’t see it coming. Stand still and let his or her emotion wash over you. There will come a point where this will stop but in the meantime the high emotion has to come out, otherwise it will fester and rot your relationship from the inside you. You don’t want that. And be loving. Always.

7. Do something novel together.

   When the time is right, do something novel and exciting together. Go away for a weekend somewhere you haven’t been before, do something together you haven’t tried before, if your relationship has been without sex for a while bring it back. This can increase dopamine in the brain and help to reinvigorate romantic love.

Relationships that have been broken by the intrusion of another can heal, provided that both people are able to feel safe from blame and shame enough to own their part in the breakage. The responsibility might not be shared evenly, and that’s okay. If you’re both still there after the affair, and both still fighting, the relationship is clearly still important. Be patient and be open to each other. A bad decision doesn’t have to mean a bad relationship. It might, of course, but it doesn’t have to. That’s what you need to both decide.

We all deserve to be adored by the one we love. When that adoration turns to another – however short-lived – the pain can quite literally be breathtaking. Some days you’ll wonder if you still have the capacity to exhale. You do. And you will. But it will take time, fight and some hard decisions. You loved each other once and if you’re both still fighting to stay together the chances are that the love is still there, but buried under too many years of neglect, obligation, and the day to day pressures that come with life. If you’ve both decided the fight will be worth it, be patient and keep fighting for it, because it will be.