Evolutionary biologist Richard Dawkins gave it a name: “When you plant a fertile meme in my mind (a tune, idea, catchphrase, or fashion) you literally parasitize my brain, turning it into a vehicle for the meme’s propagation in just the way that a virus may parasitize the genetic mechanism of a host cell. And this isn’t just a way of talking--the meme for, say, ‘belief in life after death’ is actually realized physically, millions of times over, as a structure in the nervous systems of individual men the world over.”