Since the early stone ages, we are choosing our partners, leading life with them. In that process, we also create life. In this modern age, question arises, how we choose our partners? Is it just a bet on chance? Or are we following any specific rule? Is it our heart or our basic instinct that guide us through the process?

To be precise and scientific, at the beginning of a relation, the first step is to like each other. In this step, by liking each other means liking each others structure.The basic truth is, the more symmetry in one person, the more chance to be liked. Symmetry actually refers quality. For ages, we humans have used symmetry as a mark of quality. This also happens in case of liking each other. We generally like people with more symmetry in facial structure, but perfect symmetry is not acceptable.

The second stage is to feel the attraction. Most of the studies show that, fear and anxiety increases feeling of attraction. In general cases, attraction between opposite sex can be triggered by smell of each other. This happens when our adult instincts guide us to choose our perfect genetic match. Still,a feeling of fear and anxiety rises attraction in a great deal. So if you are interested to have a successful date, go for a roller coaster ride instead of a candle light diner.

The third stage begins with physical relation, or sex. In our society, sex without marriage is not illegal, but dishonesty. To be scientific, to carry out a great, long-lasting relation, sex is very important. Having sex generates a special kind of chemical, which causes in later stages, feeling of selfless love. It is proved by tests that, the couple having more romantic sex generates a stronger relation. This stage is also the stage where future generations are produced.

After the production of children, the question arises, what binds two people if not sex? In this stage, love comes to play. As years passes, urge for sex decreases. But the chemicals produced by sex creates a feeling of love, everlasting, true, selfless love

The secret of long lasting relation, from the point of view of science, is clear now. Modern technology has revealed the chemistry behind love. But, this is not the end of it. There are many questions still to be answered.