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Cityfile has partnered with Dr. Helen Fisher to bring you the latest insight into love and romantic attraction. A renowned biological anthropologist, Dr. Fisher has conducted extensive research in the fields of human sexuality, love and marriage. She serves as Chief Scientific Advisor for the internet dating site Chemistry.com.

Question: Is there such thing as love at first sight?

Answer: The idea of love at first sight is rooted in nature. Sex is time-consuming, dangerous and metabolically expensive. There isn't a mammal on this planet that becomes instantly attracted to just anyone who comes along.

If a suitor isn't acceptable for some reason, the animal will make his/her escape. They don't have time to "date." So when the breeding season or their period of fertility begins, they either reject a suitor almost immediately or they express genuine attraction, the forerunner of love at first sight, and begin breeding fast. I think we inherited this brain response for attraction at first sight. In one study, some 10 percent of the population had experienced this sudden and compelling rush of attraction. But I suspect men have this experience more regularly than women, because men are more visual, and because men have less to lose if they fall in love instantly: They won't bear the child. But both sexes are built to fall in love rapidly—and begin the mating process.

But is it lust or love? That depends. These are different feelings and different brain systems, but the sex drive and romantic love can overlap and trigger one another. Romantic love is far more powerful than the sex drive. If you have truly fallen in love at first sight, you want much more than sex from this person—you want all of him or her.

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