A ) be nice to people because it feels good and makes others feel good?

or

B ) be nice to people because if you don't, you won't have any friends?

or, for you cool and edgy misanthropes:

C ) look out only for yourself and disregard all other forms of life?

Hard-mode, out of the three what do you actually do?

Myself, I'd like to do A but it ends up being a B with a bit of C.