Question

Why do people love?
its a hw question from d chp. bestseller by O.henry.

Answer 1

with the increase in age our mental as well as our physical nature begins to develop and at this time feeling like love , hater,, anger etc.... will develop. and LOVE is one such feeling and if people like each other or have an attraction between each other then they express it through love.
  eg;- love between two lovers,
         love between a child and his/her parents
        etc....

Answer 2

Love is a form of feeling expressed as a result of likeness and kindness towards others.people love to express their feeling. And no world without love can exists as love binds people together with harmony.