A question that has certainly been asked since the existence of man is, what is love? Various writers, composers, artists, but also ordinary people have tried to answer this ancient question. Although love is an individual experience and varies from person to person, some fundamental mechanisms of the emergence of love do not differ. As with just about any emotion, the story of the brain and nervous system is inevitable. What, then, is the neurobiology of love?
The neurobiology of love
The Oxford English Dictionary defines love as “a strong sense of attachment“, “great interest and satisfaction in something” and “a person or thing that someone loves“. The term “love” in the context of affective neuroscience is identified with “pleasure“. However, the pleasure that comes from feeling love is not the same as the pleasure that comes from eating fine food or watching a good movie. However, there are significant overlaps in the very mechanism of both pleasures.
One functional magnetic resonance imaging (fMRI) study was conducted on 17 people who were found to be intensely “in love”. Participants were asked to view photos of their loved one and photos of acquaintances. Neural mechanisms, associated with object-specific romantic love, have been identified in the right ventral tegmental area and the right caudate nucleus (parts of the brain). These are two areas that are known to handle reward and motivation. Numerous neurotransmitters are associated with the experience of love. The rewarding and pleasurable feeling of love stems from the release of dopamine which is linked to the brain’s reward system. It is a set of mechanisms of our brain that allow us to connect certain situations with a sense of satisfaction
Hormones of love
Oxytocin and vasopressin are the most prominent hormones involved in mating, as studied in monogamous animals. The main action of oxytocin is to initiate muscle contractions during birth and the release of milk during breastfeeding, but it also has an anxiolytic (relaxing) effect. Vasopressin is important for cardiovascular function and blood pressure maintenance. It is also known as the attachment hormone, increases fear and stress response, and encourages partnering in men. Oxytocin and vasopressin are neuropeptides, or small compounds that act locally within the brain in different ways. They interact with the brain’s reward system so their receptors are present in the area. Their binding to receptors can stimulate the release of dopamine. It is generally accepted that activating the reward system is important for creating relationships and connecting people, and especially for turning love into a rewarding experience.
In addition to the above hormones, testosterone has also found its role in the story of love. Testosterone is a steroid hormone secreted by the testicles of males and the ovaries of females. This hormone has several functions, including the development of the male reproductive system and secondary sex characteristics. However, testosterone is also involved in several aspects of social behavior, such as aggression, infant defense, and sexual intimacy.
Furthermore, testosterone also plays a role in romantic love. Men have decreased testosterone levels at the beginning of a new relationship, while women have increased levels from which it can be concluded that testosterone is involved in the early stages of romantic love.
Love or obsession?
Another essential neurotransmitter in the whole story is serotonin. Serotonin levels in the early stages of romantic love, which are characterized by unreasonable obsessive behavior, are reduced. Decreases in serotonin in the central nervous system are also present in several other psychiatric disorders, such as obsessive-compulsive disorder (OCD), depression, and anxiety disorder. Indeed, the initial stages of romantic love show similarities with OCD, including symptoms of anxiety, stress, and intrusive thinking. It is therefore interesting to think that early love is like a mild form of OCD, although it should be borne in mind that OCD is a group of diagnosed anxiety disorders, while love is not. However, it is concluded that serotonin is an important factor in the obsessive component of romantic love.
Perhaps answering the question of what love is through biology is not the most romantic approach, but it certainly helps to explain many phenomena and behaviors when it comes to love. Although the subjective feeling of love is special and unique for each individual, the very physiology of love in each “in love” is not too different. The brain and the reward system in the brain play a key role in making love seem like “pleasure” and “comfort.” In conjunction with the hormones of love and neurotransmitters, what happiness, what pleasure, we get a unique phenomenon that has adorned humanity since time immemorial, and that is love.
Translated by Filip Sakoman
2. De Boer, Antina, Erin M. van Buel, and G. J. Ter Horst. “Love is more than just a kiss: a neurobiological perspective on love and affection.” Neuroscience 201 (2012): 114-124.
3. Hormon ljubavi, https://www.plivazdravlje.hr/, pristupljeno 9.2.2022.