Is it really in the heart? Or the brain? The science behind falling in love

A story is told of Lord Maurice Egerton, an aviator, filmmaker and an enthusiast of architecture. He was among the first white settlers to acquire Kenya’s white highlands. 

Often spoken about is his castle, famously known as Lord Egerton Castle, that was built and completed in the 1950s. It is claimed that the baron constructed the edifice following a heartbreak after his Austrian lover dumped him. 

The story goes that the jilted man built himself this castle to protect his broken spirit and heart. He vowed never to be involved with women again.

Another story is told about a pedestrian bridge in Serbia where in the days before World War I, a school mistress and her soldier lover would meet for dates. The couple’s love story would later turn tragic when the soldier found a new sweetheart and married her. 

The woman died grief-stricken. Meanwhile, the new couple continued to go to this rendezvous for dates. Here, they would kiss, write their names on a padlock and lock it to the bridge before tossing the keys into a nearby lake.

For thousands of years of human civilisation, stories of love, requited and unrequited, and heartbreaks have abounded. In literature, music, film and other media. Some people have spoken of the feeling of butterflies in their tummy when close to their lover.  In far darker cases, others have ended their life when love was lost or not returned. 

Historically, love has been talked about from a social, religious and cultural perspective. What many people do not realise is that this phenomenon is a chemical reaction in the brain and a product of science. 

The subject has been studied by scientists for hundreds of years, with varying results. Researchers have sought to understand why we love, how we love, how love changes us and the parts of our brain that is responsible for this emotion called love. 

Sexologist and reproductive and sexual health expert Joachim Osur says love is driven by hormones such as oxytocin, testosterone and oestrogen. Others that are responsible for emotions of love are dopamine and serotonin.

Depending on where a couple is in the journey of their love, these hormones rage in their bodies and their release remains high in the first few years of a relationship.

“Nature forces us to come together through those hormones and chemicals. A relationship starts on a high note and this is the stage where the animal side of human beings overrides the rational side of them,’’ explains Dr Osur, who is also the vice-chancellor of Amref International University.

In 2020, Helen Fisher, a biological anthropologist and a senior research fellow at the Kinsey Institute, conducted brain studies on 40,000 people who were intensely in love. The participants were given photographs of their loved ones to look at. Meanwhile, their brains underwent MRI scans.

“When the subjects looked at photographs of their loved ones, the resulting MRI scans showed the areas of their brains associated with reward and motivation and rich in the chemical dopamine were activated,” explains Dr Fisher. 

The activity, Fisher detailed, happened in the ventral tegmental area of the brain, which manufactures dopamine and sends it across the body. Its release causes a person to be in a state of energy and excitement. She explains that this is the activation of the mating drive that has propelled reproduction in humans.

Romantic love, however, is a nearly linear process, according to the International Science Council, which breaks it down into lust, attraction and attachment. Each category is characterised by release of different hormones from the brain.

During the first stage of lust, the brain releases testosterone and oestrogen, sex hormones that are linked to sexual and reproductive development in both men and women. In the second stage of attraction, the brain releases dopamine, serotonin and norepinephrine, often called happy hormones. These hormones help humans to find things interesting. 

During the last stage of attachment, the body releases oxytocin and vasopressin hormones. These are responsible for positive emotions, physical and emotional mobilisation and also sparks territorial behaviour.

Dr Osur says release of oxytocin and vasopressin, which are responsible for attachment between men and women, is high in the first three years of a love relationship.

"It is expected that within the first three or four years, you will have developed a rational strategy to make it possible to stick together,’’ he says.

The council agrees, saying: “Blood flow to the brain’s pleasure centre happens during the initial attraction phase. This is also known as the honeymoon phase, when we feel an obsessive fixation to our partner.’’

This behaviour fades further into the relationship in the attraction phase as the body develops a tolerance to the release of pleasure stimulants. 

At this point, the chemicals and hormones will have started to ebb, says Dr Osur. When couples fail to build relationship development skills, they start experiencing disputes in the relationship. 

"This is the stage when most divorces occur because the chemicals are no longer pushing them,’’ he warns.

When couples navigate past the attachment phase, however, vasopressin and oxycodone create a sense of security that remains in the body throughout long-lasting relationships. 

In Fisher’s study, she also found out that men and women who possess more dopamine traits are more prone to take risks, are creative, energetic and curious and are attracted to people with similar attributes. 

Those whose serotonin is dominant attract those with similar characteristics. These people are more cautious, respectful and are likely to follow rules and traditions.

Men with higher testosterone levels are more drawn to women with equally high levels of oestrogen. In her study, Fisher discovered that testosterone-dominant people are more logical, direct, decisive and sometimes sceptical and are attracted to oestrogen-dominant people. These are more imaginative, empathetic and have higher trusting capabilities. They are also more expressive. 

This attraction among human beings is largely driven by the desire for sex.  But how do love and sex change men and women? Does it alter how they love and desire love?

Richard Scwartz, an associate professor of psychiatry at Harvard Medical School, says being in love can raise the levels of cortisol hormone, a stress hormone that may suppress your immune system by reducing production of white blood cells.

“There are different phases and moods of love. The early phase of love is quite different from later phases,’’ he narrates in an article that appeared in The Harvard Gazette.

During the first year of love, serotonin levels gradually return to normal and the “stupid” and “obsessive” aspects of the condition moderate. 

“That period is followed by increases in the hormone oxytocin, a neurotransmitter associated with a calmer and a more mature form of love. The oxytocin helps to cement bonds, raise immune function and begin to confer the health benefits found in married couples,’’ Prof Scwartz says. 

This hormone is found in couples who tend to live longer lives and experience fewer strokes and heart attacks. The professor says such people are also less depressed and have higher survival rates from major surgery and cancer treatment. 

How a couple expresses love and sex may also be disrupted by life events such as menopause, pregnancy, children and even grief. These alter how men and women engage sexually, with some of them likely to unhinge the frequency and enjoyment of intimacy. 

“Life is dynamic and comes with many psychological stresses. When a woman is going through any of them, for instance, sex may not be the first thing she wants. If she is lucky to engage in satisfying sex, though, it can calm her down,’’ Dr Osur explains.

Sex has emotional and physical aspects, with women more driven by the emotional dimension than the physicality of intercourse, he notes.

"Once a woman has had sexual intercourse with a man, she wants to be attached. She feels that she has gone to the deepest end. It is a point of no-return for her. Often, nothing else can come between her and him,’’ he says.

It is different with men, who can comfortably have sex and be fulfilled without being emotionally ready for an attachment. ‘‘The physical dimension of sex overrides the emotional side in men.’’

Conditions such as erectile dysfunction often disrupt love and sex between partners, with men taking the biggest hit, he says. ‘‘They get depressed and may even stop working. For some, it is like life has ended. This affects how they love.’’

There are also times when love ends and people part ways. Besides grief of losing a loved one, a heartbreak is one of the most devastating events in the life of an adult. It brings guilt, pain and feelings of worthlessness. Besides these, science has also shown that a heartbreak can lead to more serious consequences such as severe short-term heart muscle failure. 

Referred to as ‘‘broken heart syndrome’’ this stress occurs when a person “experiences sudden acute stress’’ that can ‘‘rapidly weaken the heart muscle.” 

Ilan Shor Wittstein, the director of Advanced Heart Failure Fellowship at John Hopkins Medicine,  says the stress can be triggered by grief, fear, extreme anger and surprise. Its symptoms include chest pain, shortness of breath, dizziness and sweating.

“When you experience a stressful event, your body produces hormones and proteins such as adrenaline and noradrenaline that are meant to help you cope with the stress. The heart muscle can be overwhelmed by a massive amount of adrenaline that is suddenly produced in response to this stress,’’ he explains.

He adds that excess adrenaline can cause narrowing of the small arteries that supply the heart with blood, causing a temporary decrease in blood flow to the heart. 

He, however, notes that adrenaline’s effects on the heart during the broken heart syndrome period are ‘‘temporary and completely reversible’’, with the heart typically recovering within days or weeks.

Interestingly, findings of research also indicate that people who have recently gone through a breakup show physical activity in their brain that is similar to when they are in physical pain. From this, researchers argue that rejection, physical and emotional pain are processed from the same parts of the brain.

Form a bond

Psychology shows that humans can also regulate how they love by either generating new feelings for someone or changing the intensity of their feelings towards the person they are currently in love with.

When people are in love, they form a bond, which is a strategy of mutual support, reproduction and cooperation. This is called a pair bond and is one of the five mammalian bonds. Other bonds are parental bonds and bonds between peers and individuals of a species. 

“A romantic relationship is a type of pair bond. It can start as mutual attraction and evolve into love over time. When you like someone, you enjoy their companionship and care about their well-being. When you love them, those feelings are unconditional,” write Janet Brito and Nancy Lovering in Psych Central, a mental health website. 
Psychology classifies relationships into seven categories namely liking, infatuation, empty love, romantic, companionate, consummate and fatuous. 

"Consummate love is the goal for many when they envision marriage or a spousal partnership. This kind of love includes commitment, passion, and emotional intimacy,” Brito and Lovering add.

According to the pair, it is possible to ‘‘love more than one person simultaneously’’ in different ways and that ‘‘emotional intimacy is present’’ in many relationships. 

Is it possible for adult men and women to love each other without sex? Dr Osur admits that this is difficult. ‘‘To develop emotional attachment and to feel that someone is a part of you, [proximity] is important. When you have sex, you are able to understand your partner’s state of mind and what they are going through.’’

He is referring to long-distance, sexless relationships, most which suffer a deterioration of emotions owing to absence of intimacy. Among the biggest threats to love, he says, not giving sex due attention ranks high.

"Couples imagine sex will come as naturally and as easily as it did when they first met. Over time, you have to put in the energy and effort to sustain love and sex. You must find ways of creating excitement so that your partner does not lose interest in you.’’

There is even a diagnosis for people without skills to sustain a romantic or love relationship, called ‘‘skills deficit disorder.’’ Dr Osur says this often occurs when an individual grew up in a family where they did not experience love or did not learn how to express or receive it.

“This is especially the case when one grew up in a dysfunctional family. Your first love is your parents. Some of these disorders are overt and others are not so obvious. Therapy helps people to get out of trauma and difficulties that one may have faced as a child. It also helps them to learn how to maintain a loving relationship.’’

While love is a chemical event in the beginning, Dr Osur says this is not the case as the relationship matures. ‘‘Love alone is not able to sustain a relationship, especially in the long term. Skills to manage it are important for sustenance.’’

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