Who influences who?

Hmmm... . Usually, when you start the day with a positive attitude, your attitude influences others and it becomes a series of positive attitude. And, when you start the day pissed with something or someone, it also starts a chain of negative attitude with the people surrounding you. Since it starts a chain, it creates a parallel of emotions or attitude throughout the day. But, what happens if a guy with a positive attitude meets a guy with a negative attitude? Which one will influence the other better? Or, better question maybe what will happen to the person in between them, who will influence him the most? Well, the answer is probably just right in front of me, just need to pay more attention to it.