There are three phases to falling in love and different hormones are involved at each stage. Events occurring in the brain when we are in love have similarities with mental illness. When we are attracted to somebody, it could be because subconsciously we like their genes. Smell could be as important as looks when it comes to the fanciability factor. We like the look and smell of people who are most like our parents. Science can help determine whether a relationship will last.
People are usually in 'cloud nine' when they fall in love. Flushed cheeks, a racing heart beat and clammy hands are some of the outward signs of being in love. But inside the body there are definite chemical signs that cupid has fired his arrow. When it comes to love it seems we are at the mercy of our biochemistry. One of the best known researchers in this area is Helen Fisher of Rutgers University in New Jersey. She has proposed that we fall in love in three stages. Each involving a different set of chemicals. Published on bbc.co.uk