The science of love

#1

Anthropologist Helen Fisher is being very patient. I have cracked some weak jokes; she laughed politely. I talked too long about myself; she indulged my rambling. And now she's trying to convince me - with intermittent success - that my relationship isn't doomed.

Fisher knows something about love. She's written several books on the science of attachment - that is, the biochemical reactions behind everything from a first crush to a lasting marriage. She has stuck the hopelessly smitten into MRI machines and peered at their brains. She has even popped up on Oprah. And four years ago, she was tapped by executives at U.S.-based Match.com, one of the world's largest dating sites, to study the neurological mechanisms that direct our romantic choices.

There are well over 100 chemicals firing in our brains at any given moment. Some keep our hearts beating, some keep our eyes blinking, and, according to Fisher, four of them - serotonin, dopamine, estrogen and testosterone - help govern a wide range of behavioural traits. These chemicals interact in different ratios in different people, creating what Fisher considers four primary personality types. Each type has a natural match as well as a few decidedly unnatural ones. You can see where this is going.

Armed with her knowledge, Fisher developed a lengthy questionnaire centred on neurochemistry, tested with 40,000 Americans and perfected on more than six million men and women across 35 countries. The questionnaire now pairs up potential suitors on Match's sister site, Chemistry.com, for which Fisher is chief scientific adviser; it can also be found in her new book, out this month, called Why Him? Why Her?, a guided tour through these personality types.

I took the test. It was a lovely, sunny morning. My boyfriend had just made pancakes and, better still, an enormous pile of bacon. I cracked the book open. Am I patient, cautious, domestic? Er, not exactly. (Note: I did not make the pancakes.) Then I can't call myself a Builder, Fisher's term for a personality powered by the chemical serotonin.

Would my friends say that I was impulsive, adaptable or obscenely late? Maybe just that last one. It wasn't looking good for me as a dopamine-fuelled Explorer. And no, I'm not overly trusting, and I'm pretty sure no one's ever compared me to Gandhi. So scratch the estrogen-driven Negotiator off my list. But analytical, skeptical, extremely competitive? Someone who can be demanding? Was my childhood nickname not Bossy Boots?

I am a Director. My brain is flooded with testosterone. This explains the high cheekbones, the man-sized hands and why I kill at Tetris. (Directors are highly skilled at spatial games.) It also explains why I immediately thrust Fisher's questionnaire at my boyfriend: I had managed to turn a personality quiz into a competition.

Because he is also competitive, he grabbed a pencil. This should have tipped us off; sure enough, he's a Director, too. We flipped through the book, learning that Builders pair well with Builders (they're both devoted to family), Explorers gravitate to Explorers (they seek out adventure), and Directors and Negotiators complement each other's temperaments.