What’s Love Got To Do With It: The Science of Love

What is Love?

Is it merely a chemical reaction? A culturally constructed concept that represents the biological mechanisms involved in falling in love? Is it a product of evolution which aims to promote reproduction and the survival of the human species? Or is it just the name of Haddaway’s 1993 classic that has cemented its place in meme culture?

“What is love?” was question that seemed to be on Haddaway’s mind when he released this hit. (Source: YouTube)

Research by Helen Fisher conducted at Rutgers University defines romantic love according to brain chemistry. The anthropology professor proposed 3 stages of romantic love—namely lust, attraction, and attachment. Each stage involves different chemicals within the body, specifically in the brain.

The 3 Stages of Love

Stage 1: Lust

Many people tend to conflate lust with love, leading to complicated situations. (Source: Bustle)

Let’s get physical…or chemical rather. Initial physical attraction motivates the need for sexual intimacy. Two sex hormones have been identified as responsible for inducing the feeling of lust within the brain: testosterone and estrogen.

The hypothalamus in the brain stimulates the production of these hormones. Not only do they increase the libido (sex drive) of both females and males, but they spark the initial attraction between partners and promote mating tendencies.

However, it is important to note that lust is not synonymous to love. Checking someone out because you think they’re attractive doesn’t mean you’ve been struck by Cupid’s arrow. To illustrate, in a study which injected men with testosterone, males only developed short-term infatuation with potential lovers. No long-term attraction or attachment was observed; it was purely lust.

What’s the purpose of lust? Is it just for sex or pleasure? The evolutionary basis of lust explains the basic need of finding a partner; a need shared by all living things. The objective is not just the act of mating itself, but to reproduce and propagate the genes of one’s species. In order to survive, we seek to resolve our sexual needs through mating.

Stage 2: Attraction

Attraction emerges after lust, which then leads to attachment. (Source: Law Of Attraction Plus)

Attraction between partners emerges from the first stage of lust. The second stage is driven by the neurotransmitters dopamine, noradrenaline, and serotonin. In what can be considered the “honeymoon phase”, people in love can’t get their lovers off of their minds, feel intense emotions (i.e. euphoria), sleep less and have a lack of appetite, yet somehow feel more energized.


This neurotransmitter plays a role in attention, addiction, desire and the motivation behind pleasure-seeking. It is released in the rewards center of the brain. Dopamine is associated with goal directed behaviour referring to the pursuit of a romantic partner – who appears to be unique, alluring, and intriguing. Your crush seems mysterious and you want to get to know them better.

Besides feelings of love, the chemical messenger is also released in response to drugs like cocaine and nicotine. These highly addictive substances (including sugar), can activate dopamine similarly to how being attracted to a new lover can. That’s right, ‘Your Love is My Drug’ is more than just Ke$ha lyrics.

Ke$ha knew what she was singing about when she sang this song. (Source: Hollywood Life)

Norepinephrine (also known as adrenaline)

High levels of dopamine are associated with norepinephrine – another chemical messenger (neurotransmitter) which involves the physiological reaction towards being around a lover. It’s the butterflies in your stomach, sweaty palms, racing heart, rapid breathing, and flushed cheeks when you’re with someone you love. This chemical is released during the human stress response in which you get excited, anxious, and nervous when interacting with your potential mate. You tend to pay them extra attention compared to other people in your life.


Serotonin maintains mood, appetite, sleep, memory, and sexual desires. As the levels of serotonin decrease in this stage, the associated functions become reduced. For instance, less serotonin means spending more time awake, or lying in bed fantasizing about your lover.

It is one of the most influential neurotransmitters which practically makes us “crazy in love”, as Beyoncé said. The philosopher Plato once declared, “love is a serious mental disease”. Low levels of serotonin are associated with individuals with obsessive-compulsive disorder (OCD) and are presumed to encourage obsessive thinking. Thus, justifying how in this stage of love, people are consumed by thoughts of their significant other.

Stage 3: Attachment

Attachment is the stage of love that emerges after the “honeymoon phase”. (Source: The Conversation)

According to scientists, the hormones oxytocin and vasopressin are involved in the attachment phase. It describes the bond and, sense of belonging between two love-sick individuals. By depending on a partner, you develop trust for one another.

After the attraction phase, levels of serotonin and dopamine return to normal, which are substituted by oxytocin and vasopressin. These two hormones keep a long-term relationship alive. It is the stage at which a couple dreams of bigger plans for their future like moving in together, getting married, or having children. This phase brings about a sense of an emotional connection, comfort, security, and protection for your romantic partner. The attachment phase applies to friends and family, apart from romantic relationships.


Better known as THE “love hormone”, the chemical is released during physical touching (i.e. hugging, kissing, cuddling, and sex) and promotes trust. Not only is oxytocin important for strengthening bonds between romantic partners, but it is crucial for mother-child relationships. The hormone is released by the hypothalamus during childbirth, breastfeeding, and when either or both sexes orgasm. Hence, why some consider sex to bring a couple closer together. However, while intimacy may bring two lovers together, oxytocin is known to be influential in jealousy, which can be detrimental to any relationship.


Released after physical touch, this hormone develops the emotional attachment and long-term commitment to another person. By studying prairie voles, a creature that resembles hamsters, researchers discovered the role of vasopressin in attachment. Since these small animals are monogamous like humans, the findings of animal research may be applied to us. When males were given a drug to reduce the amount of vasopressin in their bodies, they neglected their female partners and were less protective over their partners mating with other male competitors. Thus, vasopressin reinforces the bond between two individuals and low levels of the hormone may indicate a lack of a romantic attachment between a pair of lovers.

Voles are the token animals of monogamy (nope, it’s not us humans). (Source: Peter Trimming)

Can Science Define Love?

From a biological perspective, love is simply a cocktail of chemicals which influence our body, mind, and behaviour. Some physiological explanations of love go as far as using chemical equations to define the process of falling in love with someone. To quote the nihilistic super genius scientist Rick Sanchez from the Rick and Morty show,

… what people call “love” is just a chemical reaction that compels animals to breed.

Rick brutally dismantles Morty’s idea of love. (Source: YouTube)

Yet, others would argue that love is more than just molecules or chemicals; it’s a more abstract concept. The inability to establish a standard objective definition of love indicates it is much more complex than biology alone can explain. Everyone knows what love is, yet we define it differently. Although there is some scientific basis to the phenomenon as demonstrated by the three stages of love, there is no ‘formula’ for love.


By Sophie Jo Byfield

West Malaysian spirit of magniloquence, periphrasis and procrastination. I have half a mind...

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