The transmission of cultural traits is a process that in many ways resembles the spread of an infectious disease: the carrier of a certain idea, behavior or attitude directly or indirectly communicates this idea to another person, who now also becomes a carrier, ready to “infect” further people.

For example, after you heard your neighbor whistling a catchy tune a couple of times, you may well start whistling it yourself, thus being ready to infect some more people with the tune. Similarly, after you hear your friends recommend a new electronic tool they have bought, you may well buy one yourself, and, if you like it, start recommending it to those acquaintances who do not know it yet. Thus, cultural traits can be seen as analogous to mind viruses, idea viruses or thought contagions, which are reproduced from mind to mind via imitation or communication.

A truly successful trait is one that spreads like an epidemic, infecting the whole of the population, in order to end up as a stable, endemic component of that population’s culture. For example, the tune may become part of the repertoire of “evergreens” that everyone knows, and the tool may become as widespread as the mobile phone or colour television.