In order to replicate, memes need to be able to pass on as well as to preserve their content. The key question here is not so much which copying mechanisms support the spread of memetic information, as how any such mechanism can support the immense complexity of human culture. Any account of cultural development must include an explanation of what has enabled this complexity to increase and persist. If memes are the units of cultural evolution, then their replication methods must be able to sustain the enormous breadth and depth of information that has built up over the millennia, and meme theory must be able to account for how this happens. Following a brief look at the ways in which cultural information spreads, the bulk of this chapter is therefore given over to an examination of the key features of the replication of complexity, investigating how it might work in principle as well as how it is played out in practice, in culture as in nature.

How is Cultural Information Copied?

Imitation seems to be one of the most obvious methods by which cultural information spreads: I might learn a skill from one person by observing her actions, or pick up the musical style of another by listening to his recitals. In addition, however, there is often an intentional element in our learning. We are constantly engaged in a process of deliberate communication with each other, and this is surely the most frequent method of cultural replication.