Iasmina Hornoiu |
The era of globalisation that we live in, aiming at connecting different parts of the world and expanding international economic, cultural and political activities, has to some extent resulted in the exact opposite of what it was intended to achieve. The Brexit vote, the electoral victory of Donald Trump and his ‘new’ Afghan strategy, the rise of an aggressive religious fundamentalism and political nationalism worldwide (and the list goes on) shatter the peaceful coexistence of cultures and fuel a tendency of xenophobia. The question is: can science solve these problems?
A group of researchers from the University of Bonn, Germany have suggested that there is a pharmacological approach to “curing” xenophobia and making Europeans more accepting and generous toward refugees. This novel and promising therapy is none other than the otherwise known as “the love-hormone”, oxytocin. For more information, you can find the study here (http://www.pnas.org/content/114/35/9314.full).
At the same time, this focus offers some answers to questions regarding the reasons and mechanisms underlying the many types of love us humans experience throughout our lives.
Although at the level of the general public it seems that a lot is known about oxytocin, but the mechanisms by which it influences social bonding and love toward other people is much less clear. This article is intended to shed some light on these mechanisms and, hopefully, make the reader more familiar and maybe “in love” with oxytocin by the end of the read.
But first, let us talk about love. Why do we love and what makes us love certain people? Why is love so different depending on the subject of our affection? Is it possible to measure love? What does the complete absence of love in an individual reveal about their health state? With so many questions having been formulated throughout centuries, no wonder love has become a universal conundrum. Traversing various disciplines, it not only represents the realm of the literary, but it has increasingly become one of the central focuses in philosophy, biology, social sciences and neuroscience.
As far as the neuroscientific approaches to love go, this concept is represented by affiliative bonds. Therefore, from now on we shall refer to love as such. Affiliation describes the ability of an individual to form close interpersonal bonds with other individuals of the same species. Three prototypes of affiliation have been identified: parental (between children and their parents), pair (between romantic partners) and filial (between friends). What these categories share in common is the hormone-neurotransmitter oxytocin.
Oxytocin acts as both a hormone and a neurotransmitter. It is associated with a variety of functions including the initiation of uterine contractions during parturition, homeostatic, appetitive and reward processes, as well as the formation of affiliative bonds. For the latter, oxytocin plays a very important role in social recognition, maternal behaviour and development of partner preferences.
Oxytocin induces the motivation to initiate sexual behaviour, the formation of sexual preferences and the increased stimulant value of the infant for its mother, via its connectivity with the mesolimbic dopaminergic neurones.
Oxytocin is produced in the hypothalamus, by the magnocellular neurones clustered in two types of nuclei: the supraoptic and paraventricular. These neurones send projections to the posterior pituitary gland, thus engaging the oxytocin system with the hypothalamic-pituitary-adrenal axis, mediating the stress response, as well as parturition and milk ejection.
Other projections from the paraventricular nucleus go to various forebrain limbic structures (e.g. amygdala, hippocampus), brainstem (e.g. ventral tegmental area) and spinal cord. There are also other areas, apart from the brain and spinal cord, which receive oxytocin signalling, such as the heart, gastrointestinal tract, uterus, placenta, testes etc. With such expended projections, it comes as no surprise that oxytocin is involved in a wide variety of processes.
In romantic and parental attachment, oxytocin induces the motivation to initiate sexual behaviour, the formation of sexual preferences and the increased stimulant value of the infant for its mother, via its connectivity with the mesolimbic dopaminergic neurones. The neurotransmitter dopamine plays a major role in the reward-motivated behaviour. Therefore, the oxytocin-dopamine interaction is key to the motivation to bond between members of romantic or child-parent relationships.
In males a different hormone mediates parental behaviour. Vasopressin can be seen as the male equivalent of oxytocin, as it modulates affiliation, aggression, juvenile recognition, partner preference and parental behaviour in males. Having said that, there are studies, which show that oxytocin, also supports paternal behaviour and is linked to the father-typical affiliative behaviour.
It is associated with a variety of functions including the initiation of uterine contractions during parturition, homeostatic, appetitive and reward processes, as well as the formation of affiliative bonds.
Oxytocin is also very important in establishing close connections with our best friends (what is known as filial attachment). According to research in this area, children start showing selective attachment to a ‘best friend’ around the age of 3. This kind of interpersonal interaction represents the first attachment to non-kin members of society, therefore, a crucial step in the normal development of any human being.
Depending on the level of positive parenting children experienced during infancy, their interactions with best friends can vary in the degree of reciprocity, emotional involvement and concern for the friend’s needs. These behaviours are modulated by oxytocin.
During the first 3 years of life, oxytocin secretion in humans depends on the parent’s postpartum behaviour (which is predicted by the parents’ own levels of oxytocin) and, in turn, determines the degree of empathy between close friends. Therefore, a reasonable assumption, which has been recently proven, is that children benefiting from high parental reciprocity during infancy develop better social adaptation and are more friendly, cooperative, and show greater empathy.
What we have just discussed is of importance for different aspects. Focusing on how oxytocin mediates different types of social bonding provides better understanding of neurodevelopmental disorders such as autism. At the same time, this focus offers some answers to questions regarding the reasons and mechanisms underlying the many types of love us humans experience throughout our lives.
Iasmina Hornoiu administers a personal blog called Finding Neuron, where she posts articles related to neuroscience. She is an undergraduate student at the University of Manchester, UK, where she studies Neuroscience. In the past, she has done an internship in Vienna, Austria, at the pharmaceutical company Boehringer Ingelheim, working in oncology research. She has previously volunteered for environmental, conservational and social projects, as well as at animal shelters, in Romania, Greece and Austria. She is passionate about classical music and horse riding. Iasmina could be followed on facebook @IasminaLivia and on ResearchGate @ Iasmina Hornoiu. The views expressed in this article are authors own and do not necessarily reflect the editorial policy of Global Village Space.