“Love is the fire that kindles the soul,” wrote the great philosopher Giordano Bruno. But what does science say about love?
Indeed, love is a feeling about which poems have been composed and songs have been sung. Throughout history, philosophers of different schools have tried to think of an explanation, to find the cause of this state, which pushes people to inconceivable actions and gives a whole range of different emotions. As only love is not called and did not try to give it a definition. The ancient Greeks distinguished four “kinds” of love – love in love (eros), affection, friendship (philia), tenderness (storge) and, finally, unconditional, sacrificial love (agape). But behind all these words there is a single feeling.
But what do we know about love other than what is told in art and philosophical treatises?
Since the ancient Greeks tried to define love, the development of science has come a long way. People have flown into space and descended to the bottom of the ocean. Powerful telescopes can observe distant galaxies, and modern microscopes allow us to see particles invisible to the naked eye. But have people progressed in understanding themselves?
Neurobiology can help us answer this question.
A huge number of chemical reactions go on in the human body every second. Breathing, muscle contraction, processing of visual, auditory, and tactile information are all regulated by biochemical reactions that may seem quite complicated at first glance. And among all the variety of chemicals involved in these millions of reactions, a class of substances called neurotransmitters should be singled out.
The peculiarity of neurotransmitters is that they participate in the transmission of electrochemical impulses between neurons. Neurotransmitters are synthesized in the body cells, after which these molecules are released into the synaptic gap – the distance between two neighboring neurons – and activate the receptors of the next neuron. This is how an impulse travels through the nervous system – from a neuron to another neuron, or from a neuron to a muscle, for example. This process is a bit like the movement of cars on the highway – if one car slows down, it sends a “stop” signal to the next car, which sends the signal further.
There are quite a few neurotransmitters, and each one has a specific function. For example, adrenaline is an excitatory neurotransmitter. Adrenaline is released in large quantities during stressful conditions. It is like a signal to the nervous system, “Threat! Mobilize immediately!”. The signals from the nervous system are transmitted to the muscles – an increased heartbeat occurs, the blood pressure rises… In general, there is a general mobilization of the body to eliminate the danger and fight the stress.
But there are not only neurotransmitters that signal a threat – there are also their opposites that signal that the situation is, on the contrary, pleasant. And, as it turned out during the research, these neurotransmitters are responsible for the mysterious feeling, which has been agitating people since ancient times and is praised in poetry and prose.
Dopamine is one of the neurotransmitters that play a direct role in the pleasure of doing something. It is one of the main factors of motivation, because it is thanks to this neurotransmitter that a person experiences the feeling of pleasure. It can be anything – eating delicious food, having sex, or any particular action. And this has the other side of the coin – it is partly because of the action of dopamine that drug addiction occurs. Drugs stimulate dopamine receptors, as a result of which a person gets pleasant feelings.
Dopamine is part of a whole system called the reward system. Its principle is very simple and based on stimulation of any behavior by rewarding in the form of positive emotions. Initially, the evolutionary process fixed the actions necessary for the survival of the species, such as eating and having sex. Do the right action, keep the reward in the form of a dopamine stimulus. It may seem that now the actions necessary for an emotional reward have become a bit more complicated, like making money, finding a comfortable home. Nevertheless, they are directly related to the very first behaviors and are also rewarded with dopamine.
Dopamine has another peculiarity: it starts to be produced before the action has taken place. That is, some subjectively pleasant situation forms in a person’s mind, and dopamine is released. A person strives to recreate this situation and, if successful, dopamine is released again. This is exactly how drug addiction works – a person experiences pleasure even before taking the drug, maybe just starting to prepare the place for it – but the dopamine has already been synthesized. At the subsequent ingestion of the drug after preparation, the dopamine has been released again. Now the person is already caught in a vicious circle.
It is ironic that love in this respect is not much different from taking drugs chemically, because the same release of dopamine into the bloodstream occurs. But now the stimulus for this is the other person and the desire to be with him, to achieve mutual affection. It is dopamine that plays an important role during the period of falling in love.
But dopamine is not the only chemical basis of love. Another important neurotransmitter is serotonin, otherwise known as the “happiness hormone. Serotonin’s functions are multifaceted – it both stimulates muscle tissue and enhances attention, helping to focus on the goal at hand. But one of these functions has to do with the brain. In the human brain, both the centers responsible for positive emotions and the centers responsible for negative emotions are stimulated. And while the role of the above dopamine is to stimulate the centers of positive emotion, serotonin is to suppress the centers responsible for negative emotion. And, logically, a lack of serotonin can lead to depression. But an excess of serotonin is also extremely harmful – in medicine there is a condition known as “serotonin syndrome”, which occurs when there is a high concentration of this neurotransmitter. Euphoria, mania, insomnia, and hallucinations are just a small part of what can occur with “serotonin syndrome.
Interestingly, during the initial stages of falling in love, serotonin levels decrease, which is partly responsible for feelings of anxiety and anxiety.
The third hormone that contributes to feelings of love is oxytocin. Thanks to oxytocin, tenderness and affection arise in the phase when the lovers’ relationship has become permanent. Oxytocin in general plays a significant role in the emergence of social bonds. High concentrations of oxytocin induce a sense of trust and benevolence toward other people. Oxytocin has even been suggested to be used in medicine to treat people with autism, since autism makes it difficult to establish social contacts and in general to recognize the emotions of others.
Oxytocin also has another function: stimulation of uterine contractions. During childbirth, so much oxytocin is released into a woman’s bloodstream that…causes such a strong feeling as a mother’s love for her child.
The human brain is a rather complex structure, but gradually there are fewer and fewer white spots in it. In the same way such a mysterious phenomenon as love gradually finds its explanation, but it does not lose all its significance.