Barnaby Joyce's affair with his former staffer Vikki Campion, and his subsequent downfall from the position of deputy prime minister and head of the National Party, made headlines for weeks. It's not surprising.

From politicians to actors and entertainers, stories of high-profile individuals caught "cheating" on their partner often make front-page news.

We believe a romantic partner is there to provide us with love, comfort and security. So people are quick to make judgements and lay blame on perpetrators of what they see as a significant violation of relationship norms and betrayal of trust.

Infidelity highlights the potential fragility of our closest and most important of relationships.

But despite the blunt belief infidelity is the result of immoral and over-sexed individuals wanting their cake and eating it too, the reality is far more nuanced. For instance, infidelity is rarely just about sex. In fact, when it comes to purely sexual infidelity, the average occurrence across studies is around 20 per cent of all couples. However, this rate increases to around a third of couples when you include emotional infidelity.

An affair is generally a sign things aren't right with someone's relationship. Without the necessary skills to heal the issues, a partner may engage in an affair as an ill-equipped way of attempting to have their needs fulfilled — whether these be for intimacy, to feel valued, to experience more sex, and so on. So, the straying partner views an alternative relationship as a better way to meet these needs than their existing relationship.

Who has affairs, and why?

Studies into why people cheat are many and varied. Some find people who lack traits such as agreeableness and conscientiousness are more likely to be sexually promiscuous, as are those higher in neurotic and narcissistic traits. Other studies find infidelity is more likely to occur among people who hold less restrictive views about sex, such as that you don't have to limit yourself to one sexual partner.

A greater desire for sex is one of the stated reasons why partners stray. ( Flickr: Intertia NC )

Other important factors relate to people's commitment to their partner and relationship satisfaction. Those low on these measures appear more likely to have an affair. Recent work suggests one of the biggest predictors of having an affair is having strayed before.

A survey of 5,000 people in the UK found striking parallels between men and women's reasons for infidelity, and neither prioritised sex. The top five reasons for women related to lack of emotional intimacy (84 per cent), lack of communication between partners (75 per cent), tiredness (32 per cent), a bad history with sex or abuse (26 per cent), and a lack of interest in sex with the current partner (23 per cent).

For men the reasons were a lack of communication between partners (68 per cent), stress (63 per cent), sexual dysfunction with one's current partner (44 per cent), lack of emotional intimacy (38 per cent) and fatigue or being chronically tired (31 per cent).

So if we have difficulty genuinely communicating with our partner, or they don't make us feel valued, we may be more likely to stray. People need to invest time and energy into their relationships. Experiencing chronic tiredness over many years means one's capacity to put in the necessary work to keep a relationship strong is also compromised.

While some couples report additional reasons, which can include a greater desire for sex, the majority speak to issues that reside either within the couple or outside the relationship. The latter can be stressors that challenge the couple's ability to make the relationship work.

If you're experiencing relationship difficulties, getting help from a therapist may well short-circuit the risk factors that can lead to infidelity.

Disclosure and therapy

Some people choose to keep their affair secret because they may want it to continue, feel too much guilt or believe they're protecting their partner's feelings. But the secret only perpetuates the betrayal. If one is serious about mending their existing relationship, then disclosure is necessary, along with seeking professional guidance to support the couple through the turbulent period towards recovery.

Most relationship therapists suggest issues around infidelity can be improved through therapy. But they also report infidelity as one of the most difficult issues to work with when it comes to rebuilding a relationship.

There are various evidence-based approaches to dealing with infidelity, but most acknowledge the act can be experienced as a form of trauma by the betrayed person, who has had their fundamental assumptions about their partner violated. These include trust and the belief that the partner is there to provide love and security rather than inflict hurt.

But it's not only the betrayed person who can experience mental health issues. Research has found that when the affair is revealed, both partners can experience mental health issues including anxiety, depression and thoughts of suicide. There can also be an increase in emotional and physical violence within the couple.

So a couple should seek professional help to deal with the aftermaths of an affair, not only to possibly heal their relationship but also for their own psychological wellbeing.

There are many approaches to counselling couples after an affair, but generally, it's about addressing the issues that precipitated and perpetuated the infidelity. One of the most well researched methods of helping a couple mend these issues involves addressing the initial impact of the affair, developing a shared understanding of the context of the affair, forgiveness, and moving on.

Therapy seems to work for about two-thirds of couples who have experienced infidelity. ( Supplied )

Choosing to stay or go

Overall, therapy seems to work for about two-thirds of couples who have experienced infidelity. If a couple decides to stay together, they must identify areas of improvement and commit to working on them.

It's also vital to re-establish trust. The therapist can help the couple acknowledge the areas of the relationship in which trust has already been rebuilt. Then the betrayed partner can be progressively exposed to situations that provide further reassurance they can trust their partner without having to constantly check on them.

Some may believe it's worth celebrating the end of a toxic relationship. ( Getty Images: Le Club Symphonie )

But if therapy works for two thirds of couples, it leaves another one third who experience no improvement. What then? If the relationship is characterised by many unresolved conflicts, hostility, and a lack of concern for one another, it may be best to end it. Ultimately, relationships serve the function of meeting our attachment needs of love, comfort and security.

Being in a relationship that doesn't meet these needs is considered problematic and dysfunctional by anyone's definition.

But ending a relationship is never easy due to the attachment we develop with our romantic partner. Even though in some relationships, our attachment needs are less likely to be fulfilled, it doesn't stop us wanting to believe our partner will (one day) meet our needs.

The impending end of a relationship fills us with what is termed "separation distress". Not only do we grieve the loss of the relationship (no matter how good or bad), but we grieve over whether we will find another who will fulfil our needs.

The period of separation distress varies from person to person. Some may believe it's worth celebrating the end of a toxic relationship, but they will still experience distress in one form or another. If the couple decides to end the relationship and are still in therapy, the therapist can help them work through their decision in a way that minimises feelings of hurt.

So infidelity is less about sex and more about matters of the heart and a misguided quest to have one's relationship needs met. The problem is that some people choose to seek their relationship needs in the arms of another rather than working on their existing relationship.

Gery Karantzas is associate professor in Social Psychology/Relationship Science at Deakin University. This article first appeared in The Conversation.