"Love" is a fiction created by Madison avenue marketeers to sell products. Fuck the Hallmark corporation!

Physiologically, "love" is probably no different than eating a good piece of chocolate and is likely just another method your body uses to get you to satisfy a biological need - procreation - just like hunger pains force you to make eating a priority.

As for relationships? If the people aren't stupid, their motives should be as follows:

Men - securing a monopoly over the sexual output of the most attractive partner he can get.

Women - securing financial resources and an increase in social status.