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The Science of Love

Is love universal? Is it a chemical process in our brains? Can it affect our health?

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Is love universal? Is it a chemical process in our brains? Can it affect our health?

Love is probably the most widely spoken about theme throughout the history of mankind. In 380 BC, in The Banquet, Plato already described love as the force that moves the world, a joy that can also be the cause of the worst sorrows. Butterflies and a tingling sensation are reflected throughout our world of literature and any form of art anywhere in the world. And anthropologists suggest that evidence of love has been found in 170 different cultures. But what of science in all this? Is love universal? Is it a chemical process in our brains? Can it affect our health? 

The chemistry of love 

il·lustracions_doctoralia-5_1According to the renowned anthropologist Helen Fisher, a world expert on sexuality, marriage and divorce from an evolutionary point of view, everything that happens in love has a chemical basis. There are 3 stages of love where various hormones intervene determining these phases: lust, attraction and attachment. The chemical that is experienced in the brain during these phases is very similar to that of a mental illness or during the consumption of a drug like cocaine. And besides, just like drugs: love is addictive.

In fact, studies show that when we fall in love we suffer the same symptoms as when we take drugs or suffer from obsessive compulsive disorder. Still, this does not mean that love is negative. On the contrary, studies show that long-term relationships and love in general, are a determining factor for good health.


Stages of Love


1. Lust or the sexual stage

This stage is driven by the hormones testosterone and estrogen.

Although it was traditionally believed that testosterone affected only men, this hormone also plays an important role in women in awakening sexual desire. In fact, to awaken this desire just under a minute is enough to start secreting hormones.

There are many elements that attract us to the other person, and most of them are unconscious. Studies suggest that a slightly lower voice, having a dog or being of the same social class are decisive in awakening this desire.


2. Attraction or the romantic stage

This is the phase where love really hits, butterflies appear and the person cannot think of anything else. The lover loses his appetite, he can’t sleep, and spends his time day-dreaming and thinking about his new love.

At this stage, a group of neurotransmitters called monoamines plays a very important role:

  • il·lustracions_doctoralia-4_1Dopamine: also activated by cocaine and nicotine. It acts on the motor system and causes tachycardia.
  • Noradrenaline: also known as adrenaline. It causes sweating and accelerates the heart.
  • Serotonin: one of the most important neurotransmitters in the game of love, and probably the one that makes us crazy.

Helen Fisher conducted a study where MRI scans were performed on three groups of individuals: one group with broken hearts, another of lovers deeply in love and a third neutral group. In the comparison between them it was perfectly clear to see the different substances secreted by the brain to different stimuli shown. So when the lover was shown a photo of his loved one it could be seen that the brain secreted much more dopamine than when they were shown a picture of an attractive person.

In contrast, subjects who had experienced a failed relationship showed activity in the dopamine system on seeing the photo of their former loved one, suggesting that they still held strong feelings, but also showed activity in brain regions associated with risk taking, anger control and obsessive compulsive problems. In particular, the scans showed activity in a part of the brain associated with physical pain.


3. Attachment or the affection stage

This stage, following on from the attraction phase, only appears if the relationship is lasting. Most teenagers remain in the previous phase and are disappointed when the levels of dopamine and serotonin decrease. Being in the previous phase, permanently, would make the individual crazy and lead to the development of a pathology.

It is at this stage of attachment where the real pair bonds and commitment are created, and that allows the reproduction of the species.

The two hormones that play the most important role are:

  • Oxytocin: also known as the love hormone. It is so powerful that it allows women to produce milk and creates the link between mother and child. This hormone is also secreted in males and females during the moment of orgasm. Thus, a necessary link for family bonding is created.
  • Arginine vasopressin: another of the key hormones for long-term relationships and creating bonds between couples.


Do we choose our mates through pheromones?


Different studies with rats have found that these rodents choose their partners thanks to pheromones captured through the vomeronasal organ that allows them to smell their suitors and select them by their immune system. Is it the same with humans?

Some scientists believe that in humans the vomeronasal organ no longer functions as in some animals and that there is no connection between the organ and the brain. However, there is evidence to suggest that the vomeronasal organ does not atrophy and remains functional for the lifetime of a person. Thus, its function in these animals and humans, if real, is still a mystery.

In 1995 Claus Wedekind, from the University of Bern in Switzerland, asked a group of women to smell sweat soaked shirts from different men. The scientists found that the women studied preferred shirts with the sweat of men who had a different immune system to their own. So there would be a parallel to what rats do to choose their sexual partner through pheromones.


Does love make us crazy?


During a 1990 study in Italy it was found that the people studied who said they were in love had some of the symptoms suffered by those with obsessive compulsive disorder. In addition, the subjects had lower serotonin levels than the average for the population. Decreases in serotonin are closely related to depression and anxiety.

Other studies show that low levels of serotonin are associated with increased sexual activity and therefore, with the first phase of love.


It is possible to recapture the magic of the beginning?


Larry Young, a researcher at the National Centre of Primatology at the University of Emory in the United States, says that deciphering the chemical components of love could lead to the development of a drug that decreases or increases our feelings towards others and that way bring back the lost magic thanks to a simple pill.

But meanwhile, some studies show that doing new activities with a spouse can help rekindle the love. In one study, several couples were assigned a weekly activity that both found new and exciting, like sailing or an art class. Another group did enjoyable activities with family or friends, such as having dinner together. According to their responses, couples performing new activities showed improvements in the quality of their marriage as opposed to those who did the same things every week. The lesson is that to share new experiences with a spouse appears to trigger changes in the brain that mimic the early days of being in love.