When marriage fails to deliver what it promised, is infidelity inevitable?

"We are all more intelligent than we are capable, and awareness of the insanity of love has never saved anyone from the disease." So says philosopher Alain de Botton in the talk On Love. And he's right - love is a disease. In fact, it's an addiction.

At least it is according to scientific organisation The Anatomy of Love, headed by biological anthropologist Helen Fisher. The Anatomy of Love dedicates its work to researching exactly what heartbreak and love do to our brains. The institution's team of neuroscientists explore the science behind love and its various states.

One of the studies found that heartbreak lights up the same part of the brain as toothache. Studying newly heartbroken participants, the researchers saw activity in the anterior insula, "a brain region linked not only with the distress that accompanies physical pain, but with physical pain itself".

The Anatomy of Love conducts its research by putting participants in a scanner that uses something called functional Magnetic Resonance Imaging (fMRI), which records what people's brains "are doing as they think".

The organisation compares the end of a relationship to withdrawing from cocaine. Researchers write: "As the cocaine addict becomes highly anxious without their drug, the lover suffers 'separation anxiety' when out of touch [with their former partner]. Even worse, when rejected they often love even harder - frustration-attraction."

They continue: "Like the cocaine addict who will do just about anything to get their drug, lovers are emotionally and physically dependent. Most are willing to do dangerous or inappropriate things to regain their mate. They lose their self-control, a central trait of any addiction."

This makes sense - how many of us have thought about following our exes (even stalking them on social media is common) and just showing up at their place unannounced? Worse, how many of us have done it?

One of the things that can cause heartbreak and perhaps spell the end of a relationship is cheating, a subject that psychotherapist and author Esther Perel (who has collaborated with Fisher on numerous occasions) focuses on.

In her 2015 TED talk titled Rethinking Infidelity: A Talk for Anyone Who Has Ever Loved, Perel, who counsels couples in the aftermath of an affair, says cheating shouldn't spell the end of a relationship but rather signal the start of a new one with the same partner.

"Today in the West, most of us are going to have two or three relationships or marriages, and some of us are going to do it with the same person. Your first marriage is over. Would you like to create a second one together?"

In the same talk, Perel ponders the meaning of monogamy, saying: "Monogamy used to be one person for life. Today, monogamy is one person at a time."

Earlier in the talk, she says: "When marriage was an economic enterprise, infidelity threatened our economic security. But now that marriage is a romantic arrangement, infidelity threatens our emotional security."

She points out that in her experience with her clients, she has noticed that "quite a lot of people who have affairs may feel terribly guilty for hurting their partner but they don't feel guilty for the experience of the affair itself".

The talk has been viewed 7-million times on YouTube and 12-million times on the TED website. Perel also has a fabulous podcast called Where Should We Begin?

While Perel thinks that relationships can and often do survive the betrayal of infidelity, she also points out the changing times mean that back in the day, partners were encouraged to stay with a straying lover but that today "choosing to stay when you can leave is the new shame".

Watching Perel's talks online, reading her work and listening to her podcast have been transformative for me, heavily influencing the way I view relationships, and helping me heal from infidelity.

In a blog post titled Why Is Modern Love So Damn Hard? (on her website), Perel looks into the unrealistic expectations we have of our partners, and how that can lead to straying.

"As almost all of our communal institutions give way to a heightened sense of individualism, we look more frequently to our partner to provide the emotional and physical resources that a village or community used to provide," she writes.

But infidelity doesn't apply only to monogamous relationships. People can cheat even in polyamorous and polygamous relationships, because those relationships, too, are built on trust and a set of terms that must be adhered to.

As in her TED talk, Perel says the changing meaning of marriage and its romanticisation also helps breed infidelity: "Once we strayed because marriage was not supposed to deliver love and passion. Today we stray because marriage fails to deliver the love, passion, and undivided attention it promised."

As Perel writes in her latest book, The State of Affairs: Rethinking Infidelity: "Love is messy; infidelity more so. But it is also a window, like none other, into the crevices of the human heart."

The Anatomy of Love shares the following thoughts: "The human brain is remarkably resilient. No matter how painful heartbreak is, we are almost always able to love again."