The Science of Love and Attraction

Ever wonder what goes on in your body when you find someone you fancy? What attributes make people attractive? Is love just a chemical reaction? Una Harty and Greta Warren guide you through the science of love and attraction.


Love is a complex process. Anthropologists have found the existence of romantic love in 170 societies; there is not a single society that exists without romantic love. Love holds no boundaries, as the saying goes. It can encapsulate a person in a short space of time and transform their life into something so very bright and positive. But what is love? Love is a concoction of chemicals all trying to play their solo tune in this orchestra of emotions and feelings. Society has us trained to see love as something born within the heart. The symbol of the heart is used across all cultures to denote love, however we could not be more wrong with such an association. Love has nothing to do with the heart. Love is created and developed within the depths of one of the most complex structures known to man: the human brain.

Attraction begins with perceiving another person through one of the five senses. Humans are typically drawn to signs of health in a potential mate, such as shiny, silky hair or smooth, clear skin, and when we see a face that we deem attractive, we receive a rush of dopamine to the brain, giving us a high. While you may have heard that we find symmetrical faces more attractive, many other factors influence our aesthetic preferences, such as familiarity and averageness. Research shows that we find the computer-­generated average face of 200 people more attractive than any of the individual faces. When it comes to audition, studies have suggested that heterosexual men are more attracted to high pitched female voices, while heterosexual women are drawn to low male voices.

Our olfactory system, or sense of smell, also seems to play a role in attraction. It selects potential mates who are more genetically dissimilar to ourselves in order to build a stronger disease immunity for offspring. A study from Bern, Switzerland indicated that after wearing the same T­shirt for two nights without using any perfume or deodorant, women found the scent of men who had dissimilar MHC (a segment of human DNA) profiles more attractive than those with similar MHC.

Chemical factors also play a significant role in the process of love. But which chemicals are responsible for the progression of attraction into love? Oxytocin is most typically associated with the feeling of love and is sometimes even referred to as ‘the cuddle hormone’. It is generally affiliated with the close relationship of a mother and child. It is also released during orgasm and suggests why couples feel closer to each other after sex. Over a long period, oxytocin encourages attachment, hence one grows more intimate and comfortable with their partner.

There is another chemical responsible when it comes to keeping couples together in the long ­run. Vasopressin is an anti­diuretic and its general role is to control thirst. However, it is also secreted after sex from the pituitary gland in the brain. It promotes long lasting relationships by improving interpersonal relationships, social networking skills, spousal support and reducing negative communication.

Each of these chemicals serves a role in the development of the seemingly abstract love we feel. Serotonin explains why we become attached or infatuated with our new partner. Helen Fisher, a psychologist from Rutgers University, has stated that “serotonin­-enhancing antidepressants also suppress obsessive thinking, which is a very central component of love”. Dopamine or ‘the happy drug’ is also released by our brain when we feel love. It can be associated with the ‘lust’ stage of the theory which is driven by androgens and estrogens responsible for sexual gratification. Dopamine gives us an overwhelming sense of joy and fulfilment. Norepinephrine explains why we want to talk about our new lover to just about everyone we encounter. Doing so gives us a feeling of euphoria. It is also responsible for the turbulent mood swings during lover’s spats.

Psychological factors also affect how and whom we love. From a very early age we build up an ideal partner in our minds. Unconsciously, we may scan for traits of those who have played major roles in our lifetime such as our parents. Without realising, when we meet a person potential suitor, we are analysing them under these conditions. Research indicates that we determine whether we are attracted to a person in the space of the initial 90 seconds to four minutes.

Fisher has developed ‘The Three Stages of Love’ (lust, attraction and attachment) which models how love evolves. This model demonstrates how psychological, chemical and even societal factors all contribute to the feeling we perceive to be love. Fisher also states in her chemical love theory that each person has chemical families and we are more attracted to those whose chemicals match ours. These chemicals include dopamine, serotonin, oestrogen and testosterone.

Stage two of Fisher’s love­step triad, attraction, is the most euphoric of all the stages. If you are unfamiliar with that light-­headed feeling we get we are first falling in love, it is not dissimilar to donning a pair of glasses that turns up the brightness and beauty of the world. All of our senses are on high­ alert, particularly around our new lover. We can blame the dry mouth, racing pulse and cold sweaty palms on adrenaline. On the positive side, however, you’re likely to experience some stress relief and overall a better outlook on life.

When MRI scans were taken of men and women who were experiencing the second stage of love they discovered something remarkable. The levels of dopamine in their brain were similar to those of someone who had recently consumed cocaine. Over the following days, the subjects reported surges in energy, their appetites had declined, they had better attention spans and their bodies required less sleep.

The study also measured the subjects’ serotonin levels during this period. The findings suggested that women thought about their new lover throughout the course of the day more frequently than men – 65% of the day on average – and that females typically had higher serotonin levels than males overall.

If we further analyse the third and final step of Fisher’s stages of love, attachment, there are innumerable reasons as to why we grow attached to an individual. Both social and chemical factors contribute to this. Social addiction acts upon the same principles as behavioural addiction – through conditioning. We get addicted to something that rewards us. Therefore if we begin to share personal thoughts and experiences with someone who shares theirs in return, then it is a natural response to become closer to that person. This can be said for not only romantic and sexual relationships, but also those of a platonic nature.

We can also programme our brains to feel love or rather the emotions we would feel if we were in love. If you are keen to meet someone new and want to approach the task with a fresh attitude, it is recommended to do so with this sort of mind­set. Or even if you want to spice up your current relationship, aim to heighten your dopamine levels which will boost the romantic side of things. If you want a pick­me­up of oxytocin, simple things like holding hands and gentle touching will do so. And for the brave, if you want to have more sex – it is as simple as having sex. The brain is programmed to react to sex by craving it.

So you see, love is not the abstract feeling we perceive it to be. In fact, composed of chemicals and psychological factors, it is quite the opposite. In short, if you want to feel like you have just ran a marathon yet you experience no exhaustion nor hunger, simply fall in love.

Una Harty

Úna is a third year Nanoscience student and Trinity Life editor for Trinity News.