“A meme is any learned feeling, thought or behavior. Examples include thoughts, ideas, theories, practices, habits, songs, dances and moods. Memes propagate themselves and can move through a sociological “culture” in a manner similar to the behavior of a virus. As a unit of cultural evolution, a meme in some ways resembles a biological gene.
The word “meme” is a neologism coined in 1976 by Richard Dawkins to describe how one might extend Darwinian principles to explain the spread of ideas and cultural phenomena. He gave as examples tunes, catch-phrases, beliefs, clothing-fashions, and the technology of building arches.
Meme-theorists contend that memes evolve by natural selection (similarly to Darwinian biological evolution) through the processes of variation, mutation, competition, and inheritance influencing an individual entity’s reproductive success. So with memes, some ideas will propagate less successfully and become extinct, while others will survive, spread, and, for better or for worse, mutate. “Memeticists argue that the memes most beneficial to their hosts will not necessarily survive; rather, those memes that replicate the most effectively spread best, which allows for the possibility that successful memes may prove detrimental to their hosts.” <wiki>