Love on the brain: How dopamine drives our connections and relationships

Your eyes lock across a crowded room, and there’s an instant attraction as the brain releases the feel-good neurotransmitter dopamine. The resulting warm, fuzzy sensations are not so much an emotion but an ancient drive to find a mate

Sandra Langeslag: The longer people are in love, they experience less passionate love and more companionate love.

As I prepare to ask one of the world’s foremost experts on love about the neuroscience behind matters of the heart, she is in the midst of setting up her laptop with assistance from her husband. 

Though he is off camera, I hear Dr Helen Fisher warmly acknowledge him — “Thank you, sweetie”— before sitting down.

Comfortably settled, the Indiana-based anthropologist and chief scientific advisor to Match.com tells me about a tiny bundle of neurons nestled in the midbrain that plays a key role in generating the feeling of falling in love. 

Known as the ventral tegmental area (VTA), this structure pumps the neurotransmitter dopamine into several of the brain’s reward centres when we focus our attention on our beloved.

“That’s what gives you the focus, the motivation, the energy of intense romantic love, where you find you can’t eat or sleep and you’re checking your text messages 15 times per hour,” she says.

Fisher highlights the proximity of the VTA to the hypothalamus, a brain region involved in the regulation of thirst, hunger, and satiety. 

Just like thirst and hunger, she defines love as a basic “drive”, one which evolved millions of years ago to motivate us to “form partnerships and send our DNA into tomorrow”.

While it’s no surprise that romantic love dampens the activity of the brain’s rational decision-making cortex, it may be news to some that love, bringing with it a host of “warm fuzzy” sensations, is not an emotion. 

Helen Fisher: Our experience of each mating drive is influenced by different brain pathways and hormones.

The fact that romantic love is a drive independent of the thinking and reasoning prefrontal cortex has some important implications for what it means to fall in love — namely, the possibility of love at first sight.

“Let’s say you’re at the grocery store and you’re ready to fall in love, and there’s some cute boy there, and you talk to him, and he flirts with you, and you see he’s not wearing a wedding ring,” Fisher says. “Then, love can happen in an instant.”

Fisher suggests that love is not entirely devoid of reason, emphasising that romantic love, which she distinguishes from lust or infatuation, can fade just as rapidly as it emerges: “If you go out with him one night and he’s a drunk and 45 minutes late and he calls you by the wrong name, that flush of romantic love can die. But if you go out together and he’s hilarious and charming and educated and interesting and has a great job, the romantic love will continue and perhaps even get stronger.”

Fisher classifies romantic love as one of three ancient mating drives, each of which she defines based on their evolutionary functions. 

Sex drive gets us to leave the comfort of our homes in search of potential partners; romantic love narrows our focus and mating energy onto just one person; and attachment gets us to stick with that person long enough to co-parent our children.

Fisher notes that our experience of each drive is influenced by different brain pathways and hormones: Testosterone for sex drive, dopamine for romantic love, and oxytocin for attachment.

Stable partnerships

According to Dr Stella Vlachou, assistant professor in biopsychology at Dublin City University (DCU), many of these same feel-good chemicals are triggered when swiping right on a dating app. 

“Compared to meeting offline, the main difference is that the apps trigger the release of these neurotransmitters in a more intense, repetitive, and unpredictable way, which in itself can be pleasurable,” she says.

Vlachou believes we should savour the excitement of being in love with a new match. But she also warns that this digital reward loop can lead to compulsive overuse. 

This risk is part of why Fisher, who views dating apps as tools in our modern “mating” landscape, recommends transitioning from text-based communication to in-person meetups as soon as circumstances allow.

Jacqueline Olds: Companion love helps to reduce the stress hormone cortisol. Picture: Stephanie Mitchell

Jacqueline Olds, psychoanalyst and associate clinical professor of psychiatry at Harvard Medical School (HMS), explains the rationale behind this dating strategy in neuroscientific terms: “Our orbitofrontal lobe in the brain, which is the locus of social judgment, gets feedback from all five senses. If it’s only getting one input from the texts on your phone, you can’t really make a good social judgment. You need to be in somebody’s presence with all your senses alert to make good social judgments.”

Our drive to find a partner can lead to intense cravings. Fisher says when we are falling in love, the nucleus accumbens — a region of the brain linked to addiction — becomes activated. 

“Romantic love is a wonderful addiction when it’s going well but a perfectly dreadful addiction when it’s going poorly,” she cautions.

In her ongoing and yet-to-be-published research on the neurocognition of romantic love, Dr Sandra Langeslag, associate professor at the University of Missouri-St Louis, has discovered that individuals who are simultaneously in love and addicted to vaping exhibit more craving for their romantic partners when shown images of their vape and their beloved. Although these findings are preliminary, they suggest that addiction to our romantic partners may be stronger than substance addiction, especially in the early stages of a romance.

Should we be wary of our judgment when we are under the influence of love’s feel-good chemicals? 

Fisher explains that those in the throes of early romantic love undergo a reduction in the activity of the ventromedial prefrontal cortex (vmPFC)— a brain region associated with negativity bias. The resulting ability to “overlook what [we] don’t like about the person and focus exclusively on what [we] do like” can potentially blind us to red flags.

Based on her analysis of official statistics from over 80 cultures collected by the United Nations (UN), Fisher has found that “the longer you court before you wed, the more likely you are to create a stable partnership” — a trend she attributes, in part, to the diminishing effects of the honeymoon-phase “positive illusions”. 

However, if you’re still in the initial flush of romantic love, Olds has a reliable remedy for your clouded judgment. Comparing our internal warning signals to a smoke alarm, she says: “If you have an overactive alarm, you might get anxious about things that are very unlikely, whereas if you have an underactive alarm, you might not spot the red flags. You need to have some friends with good alarm systems who are frank with you and who will tell you when they think you’re with somebody totally inappropriate.”

While sex drive and romantic love may be instantaneous, Fisher believes that attachment or companion love takes time to develop, deepening through greater knowledge of one’s lover. One advantage to companion love is a reduction in cortisol, one of the stress hormones associated with the early phase of falling in love.“As you get into a comfortable long-term relationship which includes lots of touching, oxytocin and serotonin — two calming neurotransmitters associated with well-being — go up, while stress hormones go down,” Olds says.

A feeling that ‘comes and goes’

Though less stress is certainly a welcome development, many long-term couples mourn the loss of that initial euphoria. Based on Langeslag’s research, the latter dwindles within the first two to three years of falling in love or as couples progress through the traditional stages of dating, cohabitation, and marriage. “I’ve shown that the longer people are in love, the less passionate love people experience and the more companionate love they experience,” she says.

But romantic love does not have to decline over time as Fisher, who got married in 2020, has found. “I’m still madly in love with my husband, so I do some of the basic things that people who have just fallen in love do. I check my email during the day — ‘Oh did he write?’ The phone rings — ‘Oh Jeez, I hope that’s him’. So, I’m still in love with him, but I’m not up all night agonising — ‘Why did I say that?’”

In 2011, Fisher demonstrated the enduring nature of intense romantic love over decades when she and her colleagues examined the fMRI brain scans of 10 women and seven men who had been married for an average of 21 years. “We found similar brain activity in the VTA, associated with romantic love, as we saw in people who had just fallen in love,” she says.

Except that it’s not quite the same. Fisher argues that couples, even after many decades together, can still experience bursts of passionate love, but rather than being continuous, she describes it as a feeling that “comes and goes”.

Given the anthropologist’s assertion that a good partnership involves “sustaining all three brain systems — sex drive, feelings of intense romantic love, and feelings of deep attachment”, how might long-term couples rekindle some of that early passion?

Sandra Langeslag: The longer people are in love, they experience less passionate love and more companionate love.

According to Langeslag’s research, thinking positively about your beloved, as well as looking at their photographs or fantasising about sex with them, can serve as effective strategies for enhancing your love feelings and sexual desire for your partner.

Fisher attributes her and her partner’s lasting passion to novelty-seeking behaviours, ranging from romantic getaways to simple interruptions of one’s ordinary routine. Much like the early stages of romance, novelty induces dopamine release in the brain, giving rise to a surge of energy and excitement.

Olds, who co-authored the book Marriage in Motion: The Natural Ebb and Flow of Lasting Relationships with her husband Richard Schwartz, also an HMS associate clinical professor of psychiatry, echoes a similar sentiment. “It’s not a passive process - it’s an active process of continuing to be curious about the other person,” she says.

From the firing of neurons in the VTA to the release of dopamine and norepinephrine, romantic love is perhaps best described as a biological symphony orchestrated by the brain. And though the initial rush of euphoria inevitably wanes, there’s consolation in the knowledge that the same magic can be rekindled regardless of how many decades have passed.