The science of falling in love

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The writer is a science commentator

The scientist Helen Fisher once revealed how she ended up marrying the love of her life at 75. After months of chaste socialising, she and her beau played a game of pool, each having written down on a cocktail napkin what they wanted as a prize if they won.

After he triumphantly potted the winning ball, she opened his napkin to reveal the words: “sex and clarity”. Her napkin read: “a real kiss”. The eventual arc of their relationship — from friends to bed mates to spouses — would have been little surprise to Fisher, an anthropologist who studied the science of love and attraction. Both friendship and lust, she believed, could blossom into romantic love and then a deeper attachment.

Fisher, who died of endometrial cancer last month aged 79, left a striking legacy: legitimising love as a subject worthy of scholarly inquiry while somehow not diminishing its magic. Early on, science did not quite know what to make of her: as she told it, a reviewer rejected one of her papers on the basis that love was a supernatural phenomenon. Her punchy response was a string of books bearing such titles as The Sex Contract: The Evolution of Human Behavior and Anatomy of Love: the Natural History of Monogamy, Adultery and Divorce.

In 2005, while at Rutgers University in New Jersey, Fisher and colleagues used MRI technology to scan the brains of the besotted. Photos of a sweetheart, she found, prompted a rush of dopamine in the brain. Love was indeed not supernatural: it was an all-consuming, primal, hard-wired drive, akin to hunger and thirst, especially for the rejected. Being in love, she memorably quipped, was like having someone “camping inside your head”.

Fisher spent her career trying to figure out what we all long to know: how do we find that special someone who triggers our circuits? She divided people into four personality types, which she tied to their brain chemistry: risk-taking “explorers”; rule-loving “builders”; logical and analytical “directors”; and imaginative, empathetic “negotiators”. If you met your partner through match.com, you probably have Fisher to thank: the dating site, which she advised from 2005 until her death, used her inventory to play Cupid to millions.

Importantly, she took her insights out of the laboratory, dispensing unstuffy advice in Ted talks and interviews. Go ahead and use artificial intelligence in online dating to write a profile, she said in a podcast earlier this year: it can boost your confidence about making initial contact. “Then you go out, and your ancient human brain kicks into action . . . and you assess [potential partners] the way you always did,” she reassured.

She also advised online daters not to binge. Infinite choice simply paralyses our ancient brains. Her tip: pick between five and nine potential matches who are “in the ballpark” and give them a go. And don’t give up too soon; just because they don’t roar at your first joke doesn’t mean they lack a GSOH. Always a progressive, she praised younger generations, including those in polyamorous relationships, for taking longer to settle down. But there was also wise counsel to those in long-established relationships casting around to recall the passion of the early days. Staying together, she insisted, entailed working at all three phases of love that she identified: sex-based lust, romantic love and then attachment.

“Have sex,” she advised bluntly, on the same podcast. “Don’t tell me you don’t have time. You have time to get your hair cut.” To sustain romantic love, share novel experiences; maybe take up a new hobby together. As for attachment: hug, kiss and sit next to each other on the sofa when you watch TV. Closeness stokes the feel-good chemicals that keep couples roped companionably together.

Still haven’t finalised your weekend plans? It’s time to cancel the haircut.