What a good question. I very recently posed one very like
it to another list: memetics. Everyone agrees that the
emotional aspects of memes are very important, but it
appears that, where what's actually transmitted from one
person to another is an emotion, that can't be considered a
meme. Memes are elements of culture, and while emotions
and emotional contagions are no doubt necessary for culture,
they are not sufficient.
-- Robin