A smitten couple lean in for a kiss in a hotel lobby as I beeline towards a softly lit conference room buzzing with first-date energy. I am here to attend the Love, Actually and in Theory meeting, organised by the Royal Society, in Edinburgh, UK. As a romantic myself, I am hoping to get an answer to one of life’s biggest mysteries: what is love?

Over the next two days, I heard dozens of researchers – from evolutionary biologists and neuroscientists to psychologists – share their perspectives on that instinctive-yet-elusive thing called love, with a heavy focus on the romantic kind.

The meeting marked the first time many of the major players involved in love research have been in one room. “This is a big deal for love science. It makes me cry,” Adam Bode at the University of Melbourne, Australia, told me midway through the conference, his eyes welling up.

Love research has long been underfunded due to it being seen as a “soft” science, says Bode. “There’s been an impression since the beginning that the science of love is not a serious science,” he says. “The fact that the oldest scientific institution in the world, and probably the most respected, is funding people from all around the world to come and talk about love gives it a degree of legitimacy that I think has been lacking until now.”

To study love, we first need to define it, which is a tricky thing to do. “We, as scholars, aren’t yet at the moment where we can agree on what love is,” said Marta Kowal at the University of Wrocław, Poland.

Some simply see love as an emotion. After all, we subjectively feel it in the same way that joy or sadness varies from person to person, and it isn’t always rational. “I got interested in love because I fell in love with someone I didn’t want to [and] I wanted to understand that,” says Bode.

But most researchers I spoke to agree that romantic love is much more than just an emotion. One alternative perspective is that it is a motivational state that should be defined by the way it drives us to stay close to our partners and, in some cases, reproduce, extending the survival of our species.

This has been backed up by brain-imaging studies that found love lights up reward pathways deep in the brainstem that control basic drives. “It’s part of our survival system, like hunger or thirst,” said Lucy Brown at the Albert Einstein College of Medicine in New York.

Other scientists, however, prefer to view love in terms of a long-standing psychological idea proposed by Robert Sternberg at Cornell University in New York state. This posits that love has three core pillars: intimacy, passion and commitment. The intimacy part refers to the desire to be emotionally close to another; the passion component is about finding someone physically attractive; and commitment captures the desire to maintain a relationship.

Sternberg told the conference that his idea was inspired by his own life. “With Mary, I had a really intimate relationship; with Julia… I couldn’t keep my eyes off her, I had passion,” he said.  “Then there was Ellen, with whom I had commitment.”

One thing researchers seem to agree on is that romantic love goes through distinct stages: there is the initial honeymoon phase filled with intense desire, generally lasting up to one or two years, followed by companionate love. That’s “more pragmatic than poetic – it’s less intense”, said Kowal. “But it’s not a clear distinction, it’s more of a continuum, and a person can go from one side to the other.”

The feeling of obsession that often comes with passionate love could also be included in its definition, says Bode. People who are newly in love spend roughly half of their waking hours thinking about their love interest, making them easily distracted, he said. “I don’t think people who have recently fallen in love should be allowed to drive – I’m working on a grant [to research this].”

In a final discussion, I listened as researchers made plans to lay out multiple definitions for love in a scientific paper over the coming months. I am certain it won’t solve the mystery of what love is, but I still think it is a worthwhile endeavour, given that love is what I, and indeed many of us, live for.