Ever find yourself feeling more cranky when you're around someone whose in a crabby mood?
** Or **
Find your mood lifting when you are around a person who is happy and buoyant?
When people are in a particular mood, be it persnickety or pleasurable, that mood is often communicated to others. Remember when Orson Welles created a panic with his radio theater broadcast of The War of the Worlds - leading listeners to believe that the Earth was being invaded from aliens in outer space? THAT was emotional contagion.
Contagion is a very powerful phenomenon. Seems that we are hard wired to read subtle cues in others, a monkey see, monkey do kind of thing. So, it begs the question - how do you know if you've "caught a mood"?
Do an internal check and see if your current emotional state can be traced to something real within you or if it was picked up along the way. If it's a good emotional contagion, I say ride the wave. If it's a negative one, change your environment. . . allow yourself to fall into more lighthearted experiences.