Why do you get attracted to someone and not to others?
The Chemistry of love: ? Results of this survey is coming - why one person pulls/ attracts you and not others?
"Love is deeply embedded in the brain". It is deeply addictive, and even more so when rejected by the other person.
Not only in humans, attraction and preference for one particular individual within a species is also exhibited in animals eg. elephants.
"Why do we crave love so much, even to the point that we would die for it? To learn more about our very real, very physical need for romantic love, Helen Fisher and her research team took MRIs of people in love -- and people who had just been dumped." - TedTalk.