Love is...
Scientific edition
Every year on the eve of Saint Valentine's Day a host of articles and videos about scientific approach to love emerges. This year we'd like to join the rest.
We chose wrappers of Love is… bubble gum as a medium to tell you about the nature of love. Open up each of them and go on a date, taking with you not only a bouquet of flowers, but knowledge as well.

Anthropologist Helen Fisher is considered to be a pundit in love sphere. She's 74 already, so this lady knows what she's talking about. Fisher has formulated a theory about three types of love. The first is lust, it comes down exclusively to the satisfaction of sexual needs. The source of lust is the oldest structures of our nervous system, the so-called triune brain.

Sex drive often arises as a response to simple incentives: the appearance of a potential partner and behaviour patterns. For women a formidable look is important, which signals the ability to fight and protect resources. Of greatest importance is the physical development of the upper body (arms, shoulders, back, pectoral muscles). Their contribution to the overall attractiveness of men is 70%. Another 10% is height and absence of excess weight.

Usually women deny that they are primarily attracted to the appearance of men, but the data from dating services shows the opposite. Thus, the female audience of the OkCupid website ranked more than 80% of male users as unattractive, which blocked their opportunity to meet and chat.

Social psychologists also confirm the value of attractiveness. The scientists asked young women (aged 15 to 29) to choose a potential partner by photographs and character description of men. Their mothers (aged 37 to 61), in turn, were to choose boyfriends for their daughters relying on the same information. It turned out that the appearance was a primary factor for both groups, even if character included such features as respect, honesty, trustworthiness. Women showed interest in character only if a man was considerably attractive for them.

For men, appearance is generally number one priority. The main factors are a pretty face, long legs, medium-sized breasts and a ratio of the width of the waist and hips not higher than 7 to 10.

According to Fisher, the second type of love is attraction. It's more complex than mere sex drive. That's exactly what poets and artists have always been carolling.

Overwhelmed by romantic passion, a person is constantly in high spirits, feels increased energy. This is due to dopamine. Neurons of the "reward system" in the ventral region of our brain secrete it, which normally causes a feeling of pleasure and satisfaction. However, in lovers' brains dopamine production is increased so much that they experience euphoria.

All the beloved's attention is focused on each other. The partner seems to be someone special and the only possible of all people. This is because dopamine also affects attention processes, affecting the back of the cingulate gyrus. This area of the brain is responsible for the ability to shift attention from one object to another, to switch between different thoughts.

At the beginning of a romantic relationship, increased activity is always observed in the back of the cingulate gyrus. Gradually, over 12 months, it falls to normal values.
Another important change takes place in a lover's brain. The production of serotonin is significantly reduced. In just six months of relationships, its number drops to the same level as in patients with obsessive-compulsive disorder. A loving person is constantly haunted by obsessive thoughts about the partner. It is difficult for them to concentrate on any activity, as they constantly fall into love dreams. Even being together, lovers can't get enough of each other's company. Parting becomes like a torture.

Besides that, serotonin is responsible for estimation and comparison. So, since its production is reduced, a lover can't judge properly about the partner's traits, and only positive features are noticed, while drawbacks are ignored.

These drastic differences in brain's work make attraction more powerful than sex drive. As Helen Fisher noted, nobody has committed suicide because of being rejected in sex, but many has because of the broken heart.

The feelings of the lovers are strong, the impressions are fresh and deep. This effect is caused by dopamine, norepinephrine and phenylethylamine. The last two substances are natural stimulants. They rebuild the work of perception and memory. The whole world begins to play with bright colours, the touch becomes much more exciting, and even the smallest details are noticed and remembered in the appearance of a partner.

Moreover, dopamine stimulates the production of testosterone, which enhances sexual desire in both men and women. A love act gives a discharge only for a short time. Lust again quickly grows to the limit. Lovers stay in the bed for days, only briefly distracted to have a bite and regain strength.

However, this mixture of dopamine, norepinephrine and phenylethylamine has a reverse side. The constant internal stimulation provoked by it is evaluated positively by the brain only in the presence of an object of love. Any quarrel, separation or inattention instantly changes the sign of emotions. Euphoria gives way to anxiety, despair and panic. At the same time, the production of phenylethylamine is sharply reduced. The brain, accustomed to a constant high dose of stimulants, immediately responds with a depressive reaction. Unhappy lover literally dries of longing.

The third type of love is attachment. Unfortunately, romantic passion gradually weakens. The human body is simply not able to maintain such a high level of dopamine, norepinephrine and phenylethylamine production for a long time. Usually, the period of "acute" love lasts no more than a year, then over another two to three years the feelings gradually cool down. Most divorces happen between four and seven years of marriage.

Biologists attribute this fact not only to the exhaustion and inability of the brain to maintain the same level of activity for many years. Perhaps the reason is purely evolutionary - after four years, the offspring becomes independent enough so that a woman can stop taking care of him and have new children.

In modern hunter-gatherer societies, women, as a rule, give birth to children with a difference of about four years. The baby is weaned at the age of a little over three years, after which older siblings or grandparents look after them. This structure of care allows couples to safely part and find new, possibly more suitable partners, with whom they will have more children.

Such serial monogamy could be extremely useful for the survival of our ancestors, because the birth of children from several different partners leads to the appearance of offspring with great genetic diversity, which increases the chances of survival of the entire population as a whole.

However, many couples form and maintain a stable emotional attitude towards the partner. Attachment substitutes attraction, and it can last a lifetime.

Intensive sex is important not only for the discharge of accumulated emotional arousal, but also for the further formation of a sense of attachment and deep relationship. The central role is played by oxytocin and vasopressin. They are produced mainly with physical proximity, starting from hugs and kisses, ending with the maximum release during orgasm.

In addition to the frequency of sexual intercourse, their duration is of great importance. St. Petersburg scientists have found that women have two types of tone profile of the autonomic nervous system. The first, sympathetic, leads to the depletion of a woman's strength, and the second, parasympathetic, on the contrary, gives energy and vitality. Its appearance directly depends on the duration of mutual intercourse. Moreover, if a woman achieves such a reaction during sexual intercourse, then the man after her also "restructures" his profile to parasympathetic. As a result, after sex, both partners not only feel tenderness for each other, but also are full of strength and energy.
However, hormones alone are not enough to achieve attachment. Purely psychological factors play an important role. For example, how long was the process of courtship and conquest of a woman. The longer the candy-bouquet period was, the strangely enough, both lovers consider their partner more valuable.

By the way, this phenomenon is well described by the game theory. This is an example of the so-called signal game, in which players exchange observable actions that reveal their features. By convention, any man in a competition for a woman wants to show that he is the best and most worthy of her choice. However, he may be a simple playboy who wants one-night stand. It's important for a woman not to make a mistake with the choice, since if she becomes pregnant from a playboy, then she'll have to bear all the hardships of raising a child alone. Therefore, a woman should choose the most reliable man. But how to do that?

Mathematically, the playboy's maximum gain is to get a woman as quickly as possible and spending a minimum of resources. The woman has the maximum gain - to get a long-term partner who will share with her the hardships of raising their common offspring. The "good guy" has a similar gain. Therefore, it is possible to separate the grain from the chaff only by dragging out the courtship process as much as possible, forcing both competitors to waste time and resources. In this case, the womanizer will quickly disappear, as he will understand the futility and cost of this approach. It's easier for him to switch to a more affordable target. A truly in love "good guy" will signal with his perseverance and willingness to invest resources in a woman the purity of his intentions.

Among other psychological factors that help maintain long-term attachment for decades, a central role is played by the initial idealization of the object of love. In this case, we more easily forgive the partner for the discovered flaws, since their image in our head is stronger than real circumstances. It's also very important that there's an extensive baggage of life experience shared together: travel, shared business and achievements, and sometimes even adversity and difficulties.
The more intense romantic passion is, the more intolerable any separation feels. Distances and obstacles reinforce feelings. This is due to the nature of the "reward system" in our brain. As soon as we can't get what we want, goal achievement is delayed, dopamine-producing neurons become more active, motivating us more and more. Accordingly, after adversity and overcoming obstacles, pleasure intensifies.

At the same time, in another area of the brain, in the frontal lobes, the risks are calculated: what we'll gain and what we'll lose in this or that situation. And the subjective loss from the loss of a beloved seems so high, which again puts into effect the "reward system", forcing to persistently seek love and take any risk.
Love is… when you read this article together and laugh at the author, because there's nothing more important and genuine than the magic that's happening between you now. And maybe it'll persist for many, many years :)
Black Science