Editing Meme (section)

== Memetic lifecycle: transmission, retention ==
{{See also|Diffusion of innovations}}<!-- Similar process, although memes are not necessarily "innovations". Sections "Process" and "Rate of Adoption". -->
[[File:Cassini team Abbey road.jpg|thumb|Imitating the cover of the [[Beatles]] album ''[[Abbey Road]]'' (1969), on which the band members cross the road in front of the [[Abbey Road Studios]] in a row, has become popular with fans and [[London]] visitors.]]
[[File:Milky Holmes in London (5080111215).jpg|thumb|The four actresses of the Japanese [[media franchise]] ''[[Tantei Opera Milky Holmes|Milky Holmes]]'' reenact the Beatles cover in 2010, extending the original Beatles meme by their film costumes.]]
[[File:Paris Manga - Dimanche - 2011-10-02- P1260492 (cropped).jpg|thumb|In 2011, four [[cosplayer]]s imitate the above meme during the manga convention Paris Manga 2012 at a zebra crossing in Paris, thus further separating the meme from the root situation of 1969 tied to the Abbey Road zebra crossing.]] 
Memes, analogously to genes, vary in their aptitude to replicate; successful memes remain and spread, whereas unfit ones stall and are forgotten. Thus, memes that prove more effective at replicating and surviving are selected in the meme pool.{{citation needed|date=February 2023}}

Memes first need retention. The longer a meme stays in its hosts, the higher its chances of propagation are. When a host uses a meme, the meme's life is extended.<ref>{{cite web |last=Heylighen |first=Francis |title=Meme replication: The memetic life-cycle |url=http://pespmc1.vub.ac.be/MEMEREP.html |website=Principia Cybernetica |access-date=26 July 2013 |archive-date=4 October 2018 |archive-url=https://web.archive.org/web/20181004223220/http://pespmc1.vub.ac.be/MEMEREP.html |url-status=live}}</ref> The reuse of the neural space hosting a certain meme's copy to host different memes is the greatest threat to that meme's copy.<ref>{{cite web |last=R. Evers |first=John |title=A justification of societal altruism according to the memetic application of Hamilton's rule |url=http://pespmc1.vub.ac.be/Conf/MemePap/Evers.html |access-date=26 July 2013 |archive-date=6 October 2018 |archive-url=https://web.archive.org/web/20181006162715/http://pespmc1.vub.ac.be/Conf/MemePap/Evers.html |url-status=live}}</ref> A meme that increases the longevity of its hosts will generally survive longer. On the contrary, a meme that shortens the longevity of its hosts will tend to disappear faster. However, as hosts are mortal, retention is not sufficient to perpetuate a meme in the long term; memes also need transmission.

Life-forms can transmit information both vertically (from parent to child, via replication of genes) and horizontally (through viruses and other means).
Memes can replicate vertically or horizontally within a single biological generation. They may also lie dormant for long periods of time.

Memes reproduce by copying from a nervous system to another one, either by communication or [[imitation]]. Imitation often involves the copying of an [[observation|observed]] behavior of another individual. Communication may be direct or indirect, where memes transmit from one individual to another through a copy recorded in an inanimate source, such as a book or a [[Sheet music|musical score]]. Adam McNamara has suggested that memes can be thereby classified as either internal or external memes (i-memes or e-memes).<ref name="mcnamara" />

Some commentators have likened the transmission of memes to the spread of [[infectious disease|contagions]].<ref>{{harvnb|Blackmore|1998}}; "The term 'contagion' is often associated with memetics. We may say that certain memes are contagious, or more contagious than others."</ref> Social contagions such as [[Bandwagon effect|fads]], [[Hysterical contagion|hysteria]], [[copycat crime]], and [[copycat suicide]] exemplify memes seen as the contagious imitation of ideas. Observers distinguish the contagious imitation of memes from instinctively contagious phenomena such as yawning and laughing, which they consider innate (rather than socially learned) behaviors.<ref name="defmeme">{{harvnb|Blackmore|1998}}
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[[Aaron Lynch (writer)|Aaron Lynch]] described seven general patterns of meme transmission, or "thought contagion":<ref name="lynch">{{harvnb|Lynch|1996}}</ref>

# Quantity of parenthood: an idea that influences the number of children one has. Children respond particularly receptively to the ideas of their parents, and thus ideas that directly or indirectly encourage a higher birth rate will replicate themselves at a higher rate than those that discourage higher birth rates.
# Efficiency of parenthood: an idea that increases the proportion of children who will adopt ideas of their parents. Cultural [[separatism]] exemplifies one practice in which one can expect a higher rate of meme-replication—because the meme for separation creates a barrier from exposure to competing ideas.
# Proselytic: ideas generally passed to others beyond one's own children. Ideas that encourage the [[proselytism]] of a meme, as seen in many religious or political movements, can replicate memes horizontally through a given generation, spreading more rapidly than parent-to-child meme-transmissions do.
# Preservational: ideas that influence those that hold them to continue to hold them for a long time. Ideas that encourage longevity in their hosts, or leave their hosts particularly resistant to abandoning or replacing these ideas, enhance the preservability of memes and afford protection from the competition or proselytism of other memes.
# Adversative: ideas that influence those that hold them to attack or sabotage competing ideas and/or those that hold them. Adversative replication can give an advantage in meme transmission when the meme itself encourages aggression against other memes.
# Cognitive: ideas perceived as cogent by most in the population who encounter them. Cognitively transmitted memes depend heavily on a cluster of other ideas and cognitive traits already widely held in the population, and thus usually spread more passively than other forms of meme transmission. Memes spread in cognitive transmission do not count as self-replicating.
# Motivational: ideas that people adopt because they perceive some self-interest in adopting them. Strictly speaking, motivationally transmitted memes do not self-propagate, but this mode of transmission often occurs in association with memes self-replicated in the efficiency parental, proselytic and preservational modes.