Perhaps the most crucial determinant of whether we like someone is whether he or she likes us. this best illustrates the power of

I believe the answer is:  reciprocal liking.
 reciprocal liking refers to a psychological condition that make individuals more likely to like someone better if they know that that someone is liking them back.
This situation is most commonly caused by the positive feeling/atmosphere that exist simply because you're being appreciated.

Ibelieve the answer is water and oil.