Think it through
The neuroscience of romantic love
Let’s begin with your brain on love. When you fall in love, your brain experiences a flurry of chemical activity that contributes to the emotional and physiological upheavals associated with romance. Key players in this process are dopamine, often referred to as the ‘feel-good’ neurotransmitter, as well as norepinephrine and serotonin. The hormone oxytocin, often dubbed the ‘love hormone’ or ‘cuddle hormone’, floods the brain during intimate moments promoting bonding, trust and attachment, and fostering feelings of closeness and emotional intimacy.
This neurochemical focus might offer insight into the puzzle of exclusivity, as the brain’s fixation on one person during this stage could make the idea of loving others unimaginable. Indeed, this chemical cocktail of love is akin to being on drugs such as cocaine – a booster of mood and motivation. Some researchers have drawn parallels between the brain chemistry characteristic of romantic love and that of obsessive-compulsive disorder.
This neurochemical profile could also shed light on the puzzle of unrequited love, as the brain’s obsessive tendencies can amplify the pain of unreciprocated feelings. The low serotonin levels observed in the early stages of love might explain why those feelings persist even when love is unreturned. In light of these considerations, expressions such as ‘madly in love’ or ‘head over heels’ make sense as lovers sometimes really do lose their wits.
Note, however, the difference between being in love and loving. The former refers to the initial stages of love, sometimes pejoratively referred to as ‘infatuation’. The latter denotes a less volatile, calmer state that you might settle into after the initial fever subsides. Infatuation is inherently unsustainable, which is why love must either fade away or transition into this quieter, more enduring form. Alternatively, you might skip the madness altogether, going directly for the tender affection that feels soothing and safe. This distinction between infatuation and long-term love also speaks to the puzzle of eternal love, highlighting how early intensity can create the illusion of unchanging passion, even though love evolves into a more enduring state over time.
While brain chemistry offers insight into the mechanisms that drive the emotions of love, it provides only a partial answer to the question ‘What is love?’ It helps explain why we feel euphoric or obsessive in the early stages, but it doesn’t fully capture the subjective, deeply personal experience of love or the myriad emotions it encompasses. Why does your brain perform these somersaults when your heart skips a beat? Why does love evoke not only joy but also vulnerability, longing and even despair?
Romantic love and evolution
Another origin story of love is told by some evolutionary psychologists. It goes roughly like this.
In the African grasslands 3.5 million years ago, a hominin species called Australopithecus afarensis left the forest for the savannah, where they supplemented their diet by scavenging the flesh of the prey left behind by predators. As they walked upright, females had to carry their babies in their arms, unlike other primates whose infants clung to their bodies. This burden made it harder for females to gather food and protect themselves. To ensure safety and resources, fathers needed to be brought in to help in raising offspring.
According to this picture, three distinct emotion systems came to drive human reproduction: lust, attachment and romantic love. Lust, with its aim of sexual gratification, evolved to motivate sexual intercourse. Attachment, the deep emotional bond that forms between a caregiver and child, keeps romantic partners together. This is vital for a species whose earliest stages of life leave them so utterly helpless. Romantic love bridges the gap between lust and attachment by fixing your attention on your beloved at least until your offspring become self-sufficient. Romantic love is an adaptation that facilitates reproduction and childrearing.
This evolutionary perspective may also shed light on the puzzle of exclusivity, by suggesting that pair bonding arose to ensure mutual commitment and shared resources for offspring. This may explain why exclusivity feels so natural to many. Interestingly, this view challenges the puzzle of eternal love, as it suggests that romantic bonds are evolutionarily designed to fade once their reproductive and child-rearing purposes are fulfilled. The evolutionary focus on practical outcomes explains the impermanence of love’s intensity. It also raises questions about the puzzle of unrequited love, as the anguish of loving without reciprocity might stem from its failure to fulfil the adaptive purposes of mutual care and reproduction. While it provides evolutionary ‘reasons’ for love – such as enhancing offspring survival – it doesn’t resolve the puzzle of reasons for love, as the personal reasons people fall in love rarely, if ever, align with the evolutionary imperatives of reproduction or child-rearing. As the poet Edna St Vincent Millay wryly observes: ‘Whether or not we find what we are seeking / Is idle, biologically speaking.’
This picture conveniently supports the ideal of the nuclear family grounded in a monogamous heterosexual relationship with the emphasis on fidelity. It suggests that our humanoid ancestors operated as a mother-father-child unit optimised for parenting. It also posits an important gender difference when it comes to jealousy. For men, the sexual fidelity of their female partner is crucial because of the uncertainty of paternity. For women, it is emotional fidelity that matters most: they need the father to provide essential resources for mother and child. This picture seems to show that gendered patterns of jealousy are fine-tuned by Mother Nature to favour the nuclear family.
There are, however, compelling reasons to be sceptical of this view.
The American anthropologist and primatologist Sarah Hrdy shows in her book Mothers and Others (2009) that early humans, much like other great apes, lived in small groups, travelling, hunting, and gathering food together. These groups had strong communal bonds, raising offspring collectively, like many Indigenous communities that exist today. As an African proverb says, it takes a village to raise a child.
This communal approach also undermines the idea that jealousy is tied to a nuclear family setup. Some contemporary Amazon societies believe that many men contribute to the creation of a single child. This is called partible paternity. These societies share parenting responsibilities among all adults, which strengthens communal bonds, instead of creating antagonism and competition characteristic of jealousy. If the Pleistocene societies were anything like the hunter-gatherer societies we see today, the exclusive involvement of fathers in rearing only their own children is unlikely.
Second, the supposition that monogamous pair-bonding was the norm in prehistoric times appears even more far-fetched when we look at marriage arrangements throughout human history. According to Stephanie Coontz, an American historian, given that polygyny (one husband, many wives) and group marriages are prevalent forms of marriage in contemporary hunter-gatherer communities alongside monogamy, it is likely that these forms of marriage have been common throughout human history. Monogamy became more widespread with the advent of agriculture about 10,000 years ago, possibly due to the creation of private property and the need to control its inheritance. The rise of monogamous marriage might be a better explanation for the purported gender difference in jealousy. Interestingly, gender differences in jealousy vary widely crossculturally, and, although the evidence is equivocal, some research has suggested that the gender difference in what triggers jealousy diminishes in more egalitarian societies.
Although Frank Sinatra once crooned that ‘love and marriage … go together like a horse and carriage’, the history of marriage tells us otherwise. Historically, romantic love was mostly shunned as too fickle a basis for the serious purposes of marriage. Marrying for love is as recent as the 18th century. Industrialisation is what has given rise to the nuclear family, rather than the need for paternal investment in the prehistoric savannah.
Are the reasons I’ve just presented enough to show that romantic love is not an evolutionary adaptation evolved to help perpetuate the human species together with lust and attachment? Unlikely. But I hope to have made clear that the origin stories provided by science do not dispel love’s mysteries. We must also pay attention to love’s actual history. The nuclear family is a modern invention, not a prehistoric structure. Placing monogamy into its historical context shows that it is not hardwired into human nature. But even if the evolutionary story presented were true, we wouldn’t be justified in concluding that monogamy, the nuclear family or jealousy are inherently good or morally praiseworthy. This would be an example of the naturalistic fallacy, where one mistakenly assumes that what is natural is necessarily good.
Let us turn now to a third origin story of love – one that argues that romantic love is a human invention of the Western civilisation.
Love as a social construct
The 17th-century French essayist François de La Rochefoucauld wrote that ‘People would never fall in love if they hadn’t heard love talked about.’ This suggests that romantic love is a social construct – a set of norms and expectations regarding when and for whom love should be felt, and how it should be expressed. You learn these rules from songs, movies and the approving or disapproving tone of gossip. You can’t fall in love with a child, or a nonhuman, or when your ages are too far apart. For a long time in our culture, it was also considered inappropriate to fall in love with someone of the ‘wrong’ sex, religion or race. These norms vary with time and place, and shape our understanding and experience of romantic love.
Some scholars, such as the 20th-century Swiss writer Denis de Rougemont, trace the emergence of romantic love to the Middle Ages as a response to the forbidding attitudes of the Church towards sex. Troubadours, poet-musicians in the courts of southern France during the 12th and 13th centuries, shaped the concept of courtly love. Their songs celebrated idealised, often unrequited romantic passion. Unable to consummate their forbidden love due to its extramarital nature, they worshipped their beloveds as pure and virtuous while saturating their songs with erotic longing.
This cultural script casts a different light on the puzzles of exclusivity, eternal love and unrequited love. The troubadours’ poetry and music became influential in Europe, embedding these ideals into the cultural consciousness. Its legacy can still be seen today: the motif of a knight in shining armour rescuing a damsel in distress is alive and well. Gender roles prescribed by the romantic script subsist: men should make the first move, buy flowers, and plan dates. Women must play hard to get, discern men’s true intentions, and secure exclusive long-term commitment.
More generally, the ‘relationship escalator’ – our dominant romantic script – looks something like this: two people meet, they go on dates, fall in love, move in together, get engaged, get married, have children. While the sequence of these steps can vary, the expectation is that a romantic relationship should progress along this socially prescribed path.
Was romantic love really invented in the Middle Ages? Probably not. Crosscultural studies suggest that romantic love existed in cultures untouched by Western influence. But it did begin to take centre stage in Europe, inspiring an abundance of art and literature.
If romantic love is a social construct, does it mean it is not real? Consider that money, time, class, gender, race, marriage, family are all social constructs. Yet they are very real: they shape our perceptions, behaviours and interactions in significant and often indispensable ways. And yet, you might wonder, how can love be a social construct given the neural profile discussed above? Doesn’t the possibility that romantic love is an evolutionary adaptation preclude the possibility of its being socially constructed?
These questions presuppose the old nature-nurture distinction: the idea that human capacities are produced either by our genes, or by our environment. But that is a false dichotomy: genes and environment interact in dynamic ways, so that certain genetic predispositions manifest only in specific environmental contexts (consider your capacity to read or to cook). Thus, if your brain goes haywire when you see that enchanting barista making your latte with flair, that is entirely compatible with romantic love having both biological and social bases.
Romantic love: a feminist critique
What does seem to follow from the cultural and social dimensions of love is that it lends itself to critique, notably focusing on the ways that traditional notions of romance perpetuate gender stereotypes and inequalities.
One well-known critic of romantic love was the French feminist philosopher Simone de Beauvoir. In her book The Second Sex (1949), she argued that romantic love reinforces women’s dependency and passivity, encouraging them to derive their identity and value from their relationships with men. Quoting Byron, she observed that: ‘Man’s love is of man’s life a thing apart, / ’Tis woman’s whole existence.’ By positioning men as the primary actors in both the public and private spheres, traditional romantic scripts perpetuate power inequality between the sexes.
You might think that this critique of love is somewhat dated, since many women freely pursue degrees and careers, enjoying more opportunities and freedoms than ever before. However, the persistence of gendered expectations in romantic relationships confirms that Beauvoir’s analysis remains all too relevant. Despite advances in gender equality, societal norms still often pressure women to prioritise romantic relationships and family life over personal ambitions and career goals. Women are still widely expected to be the primary caretakers and emotional supporters within a relationship. The idolisation of romantic love as essential to a good and happy life is yet another trap in the path of women’s liberation. Recalling Carol Hanisch’s slogan ‘The personal is political,’ we see that personal experiences such as romantic love are deeply entrenched in larger social and political structures.
Where do we go from here? Should we abandon romantic love as we shake off our shackles of oppression? Or can we reinvent it so that it serves as an instrument of resistance and liberation, rather than a tool of patriarchy? Beauvoir herself thought that:
Authentic love must be founded on reciprocal recognition of two freedoms … For each of them, love would be the revelation of self through the gift of self and the enrichment of the universe.
If she is right, there is hope for love.
