Memetics
Memetics is a neo-Darwinian approach to evolutionary models of cultural information transfer based on the concept of the meme.  Started from a metaphor used in popular writings of Richard Dawkins, it has later turned into an approach in the study of self-replicating units of culture. It has been proposed that just as memes are analogous to genes, memetics is analogous to genetics.

# History of the term
In his book The Selfish Gene (1976), the ethologist Richard Dawkins used the term meme to describe a unit of human cultural transmission analogous to the gene, arguing that replication also happens in culture, albeit in a different sense. In his book, Dawkins contended that the meme is a unit of information residing in the brain and is the mutating replicator in human cultural evolution. It is a pattern that can influence its surroundings  that is, it has causal agency  and can propagate. This created great debate among sociologists, biologists, and scientists of other disciplines, because Dawkins himself did not provide a sufficient explanation of how the replication of units of information in the brain controls human behaviour and ultimately culture, since the principal topic of the book was genetics. Dawkins apparently did not intend to present a comprehensive theory of memetics in The Selfish Gene, but rather coined the term meme in a speculative spirit. Accordingly, the term "unit of information" came to be defined in different ways by many scientists.
The modern memetics movement dates from the mid 1980s.  A January 1983 Metamagical Themas column  by Douglas Hofstadter in Scientific American was influential as was his 1985 book of the same name. "Arel Lucas suggested that the discipline that studies memes and their connections to human and other carriers of them be known as memetics by analogy with 'genetics.'"  (This might not be the earliest use of "memetics.") The massive popular impact of Dawkins' The Selfish Gene has undoubtedly been an important factor in drawing in people of disparate intellectual backgrounds. Another crucial stimulus was the publication in 1992 of Consciousness Explained by Tufts University philosopher Daniel Dennett, which incorporated the meme concept into an influential theory of the mind. In his 1993 essay Viruses of the Mind, Richard Dawkins used memetics to explain the phenomenon of religious belief and the various characteristics of organised religions.
However, the foundation of memetics in full modern incarnation originates in the publication in 1996, of two books by authors outside the academic mainstream: Virus of the Mind: The New Science of the Meme by former Microsoft executive turned motivational speaker and professional poker player, Richard Brodie, and Thought Contagion: How Belief Spreads Through Society by Aaron Lynch, a mathematician and philosopher who worked for many years as an engineer at Fermilab. Lynch claimed to have conceived his theory totally independently of any contact with academics in the cultural evolutionary sphere, and apparently was not even aware of Dawkins' The Selfish Gene until his book was very close to publication.
Around the same time as the publication of the books by Lynch and Brodie, a new e-journal appeared on the web, hosted by the Centre for Policy Modelling at Manchester Metropolitan University Journal of Memetics  Evolutionary Models of Information Transmission.  The journal has since then been taken over by Francis Heylighen of the CLEA research institute at the Vrije Universiteit Brussel. The e-journal soon became the central point for publication and debate within the nascent memetics community. (There had been a short-lived paper memetics publication starting in 1990, the Journal of Ideas edited by Elan Moritz. ))  In 1999, Susan Blackmore, a psychologist at the University of the West of England, published The Meme Machine, which more fully worked out the ideas of Dennett, Lynch and Brodie and attempted to compare and contrast them with various approaches from the cultural evolutionary mainstream, as well as providing novel, and controversial, memetic-based theories for the evolution of language and the human sense of individual selfhood.
The term is a transliteration of the Ancient Greek Template:Unicode (Template:Unicode), meaning "imitator, pretender", and was used in 1904 by the German evolutionary biologist Richard Semon, best known for his development of the engram theory of memory, in his work Die mnemischen Empfindungen in ihren Beziehungen zu den Originalempfindungen, translated into English in 1921 as The Mneme. Until Daniel Schacter published Forgotten Ideas, Neglected Pioneers: Richard Semon and the Story of Memory in 2000, Semon's work had little influence.

# Internalists and externalists
The memetics movement split almost immediately into those who want to stick to Dawkins' definition of a meme as "a unit of cultural transmission."  Typical of this first group is Gibran Burchett, the founder of Aether Lumin Research firm, who has stated that a meme can be defined, more precisely, as a unit of cultural information ... located in the brain."  A second group wants to redefine memes as observable cultural artifacts and behaviours.
These two schools became known as the "internalists" and the "externalists." Prominent internalists included both Lynch and Brodie; the most vocal externalists included Derek Gatherer, a geneticist from Liverpool John Moores University and William Benzon, a writer on cultural evolution and music. The main rationale for externalism was that internal brain entities are not observable, and memetics cannot advance as a science, especially a quantitative science, unless it moves its emphasis onto the directly quantifiable aspects of culture. Internalists countered with various arguments: that brain states will eventually be directly observable with advanced technology, that most cultural anthropologists agree that culture is about beliefs and not artefacts, or that artefacts cannot be replicators in the same sense as mental entities (or DNA) are replicators. The debate became so heated that a 1998 Symposium on Memetics, organised as part of the 15th International Conference on Cybernetics, passed a motion calling for an end to definitional debates.
The most advanced statement of the internalist school came in 2002 with the publication of The Electric Meme, by Robert Aunger, an anthropologist from the University of Cambridge. Aunger also organised a conference in Cambridge in 1999, at which prominent sociologists and anthropologists were able to give their assessment of the progress made in memetics to that date. This resulted in the publication of Darwinizing Culture: The Status of Memetics as a Science, edited by Aunger and with a foreword by Dennett, in 2000.

# Maturity
In 2005, the Journal of Memetics  Evolutionary Models of Information Transmission ceased publication and published a set of "obituaries" for memetics. This was not intended to suggest that there can be no further work on memetics. A relaunch of this journal is in the works and the journal is again accepting new submissions . Susan Blackmore has left the University of the West of England to become a freelance science writer and now concentrates more on the field of consciousness and cognitive science. Derek Gatherer moved to work as a computer programmer in the pharmaceutical industry, although he still occasionally publishes on memetics-related matters. Richard Brodie is now climbing the world professional poker rankings. Aaron Lynch disowned the memetics community and the words "meme" and "memetics" (without disowning the ideas in his book), adopting the self-description "thought contagionist".  Lynch lost his previous funding from a private sponsor and after his book royalties declined, he was unable to support himself as a private memetics/thought-contagion consultant. He died in 2005.
Susan Blackmore (2002) re-stated the meme definition as whatever is copied from one person to another person, whether habits, skills, songs, stories, or any other kind of information. Further she said that memes, like genes, are replicators. That is, they are information that is copied with variation and selection. Because only some of the variants survive, memes (and hence human cultures) evolve. Memes are copied by imitation, teaching and other methods, and they compete for space in our memories and for the chance to be copied again. Large groups of memes that are copied and passed on together are called co-adapted meme complexes, or memeplexes. In her definition, thus, the way that a meme replicates is through imitation. This requires brain capacity to generally imitate a model or selectively imitate the model. Since the process of social learning varies from one person to another, the imitation process cannot be said to be completely imitated. The sameness of an idea may be expressed with different memes supporting it. This is to say that the mutation rate in memetic evolution is extremely high, and mutations are even possible within each and every interaction of the imitation process. It becomes very interesting when we see that a social system composed of a complex network of microinteractions exists, but at the macro level an order emerges to create culture.

# Critique
Benitez-Bribiesca, a critic to memetics, calls it "a pseudoscientific dogma" and "a dangerous idea that poses a threat to the serious study of conciousness and cultural evolution" among other things. As factual criticism, he refers to the lack of a code script for memes, as the DNA is for genes, and to the fact that the meme mutation mechanism (i.e., an idea going from one brain to another) is too unstable (low replication accuracy and high mutation rate), which would render the evolutionary process chaotic.
Another scientific critique comes from semiotics, (e.g., Deacon, Kull) stating that the concept of meme is a primitivized concept of sign. Meme is thus described in memetics as a sign without its triadic nature. In other words, meme is a degenerate sign, which includes only its ability of being copied. Accordingly, the objects of copying are memes, whereas the objects of translation (sensu lato) and interpretation are signs.

# New developments
Dawkins responds in A Devil's Chaplain that there are actually two different types of memetic processes. The first is a type of cultural idea, action, or expression, which does have high variance; for instance, a student of his who had inherited some of the mannerisms of Wittgenstein. However, he also describes a self-correcting meme, highly resistant to mutation. As an example of this, he gives origami patterns in elementary schools  except in rare cases, the meme is either passed on in the exact sequence of instructions, or (in the case of a forgetful child) terminates. This type of meme tends not to evolve, and to experience profound mutations in the rare event that it does. Some memeticists, however, see this as more of a continuum of meme strength, rather than two types of memes.
Another definition, given by Hokky Situngkir, tried to offer a more rigorous formalism for the meme, memeplexes, and the deme, seeing the meme as a cultural unit in a cultural complex system. It is based on the Darwinian genetic algorithm with some modifications to account for the different patterns of evolution seen in genes and memes. In the method of memetics as the way to see culture as a complex adaptive system, he describes a way to see memetics as an alternative methodology of cultural evolution. However, there are as many possible definitions that are credited to the word "meme". For example, in the sense of computer simulation the term memetic algorithm is used to define a particular computational viewpoint.
Memetics can be simply understood as a method for scientific analysis of cultural evolution. However, proponents of memetics as described in the Journal of Memetics  Evolutionary Models of Information Transmission believe that 'memetics' has the potential to be an important and promising analysis of culture using the framework of evolutionary concepts. Keith Henson who wrote Memetics and the Modular-Mind (Analog Aug. 1987)  makes the case that memetics needs to incorporate Evolutionary psychology to understand the psychological traits of a meme's host.  This is especially true of time-varying, meme-amplification host-traits, such as those leading to wars.  See Evolutionary Psychology, Memes and the Origin of War. 
Recently, Christopher diCarlo has developed the idea of 'memetic equilibrium' to describe a cultural compatible state with biological equilibrium. In "Problem Solving and Neurotransmission in the Upper Paleolithic" (in press), diCarlo argues that as human consciousness evolved and developed, so too did our ancestors' capacity to consider and attempt to solve environmental problems in more conceptually sophisticated ways. Understood in this way, problem solving amongst a particular group, when considered satisfactory, often produces a feeling of environmental control, stability, in short--memetic equilibrium. But the pay-off is not merely practical, providing purely functional utility--it is biochemical and it comes in the form of neurotransmitters. The relationship between a gradually emerging conscious awareness and sophisticated languages in which to formulate representations combined with the desire to maintain biological equilibrium, generated the necessity for memetic equilibrium to fill in conceptual gaps in terms of understanding three very important aspects in the Upper Paleolithic: causality, morality, and mortality. The desire to explain phenomena in relation to maintaining survival and reproductive stasis, generated a normative stance in the minds of our ancestorsSurvival/Reproductive Value (or S-R Value).
The application of memetics to a difficult complex social system problem, environmental sustainability, has recently been attempted at thwink.org. Using meme types and memetic infection in several stock and flow simulation models, Jack Harich has demonstrated several interesting phenomena that are best, and perhaps only, explained by memes. One model, The Dueling Loops of the Political Powerplace, argues that the fundamental reason corruption is the norm in politics is due to an inherent structural advantage of one feedback loop pitted against another. Another model, The Memetic Evolution of Solutions to Difficult Problems, uses memes, the evolutionary algorithm, and the scientific method to show how complex solutions evolve over time and how that process can be improved. The insights gained from these models are being used to engineer memetic solution elements to the sustainability problem.
Francis Heylighen of the Center Leo Apostel for Interdisciplinary Studies has postulated what he calls "memetic selection criteria". These criteria opened the way to a specialized field of applied memetics to find out if these selection criteria could stand the test of quantitative analyses. In 2003 Klaas Chielens carried out these tests in a Masters thesis project on the testability of the selection criteria.
In Selfish Sounds and Linguistic Evolution (2004, Cambridge University Press), Austrian linguist Nikolaus Ritt has attempted to operationalise memetic concepts and use them for the explanation of long term sound changes and change conspiracies in early English. It is argued that a generalised Darwinian framework for handling cultural change can provide explanations where established, speaker centred approaches fail to do so. The book makes comparatively concrete suggestions about the possible material structure of memes, and provides two empirically rich case studies.
In A Memetic Paradigm of Project Management (International Journal of Project Management, 23 (8) 575-583) Australian academic S.J. Whitty has argued that project management is a memeplex with the language and stories of its practitioners at its core. This radical, some say heretical approach requires project managers to consider that most of what they call a project and what it is to manage one is an illusion; a human construct about a collection of feelings, expectations, and sensations, cleverly conjured up, fashioned, and conveniently labelled by the human brain. It also requires project managers to consider that the reasons for using project management are not consciously driven to maximize profit. Project managers are required to consider project management as naturally occurring, self-serving, evolving and designing organizations for its own purpose.
In The Evolution of IT Innovations in Swedish Organizations: A Darwinian Critique of Lamarckian Institutional Economics, Journal of Evolutionary Economics, vol. 17, No. 1 (Feb 2007) Swedish political scientist Mikael Sandberg (Swedish political scientist) argues against "Lamarckian" interpretations of institutional and technological evolution and studies creative innovation of information technologies in governmental and private organizations in Sweden in the 1990s from a memetic perspective. Comparing the effects of active ("Lamarckian) IT strategy versus userproducer interactivity (Darwinian co-evolution), evidence from Swedish organizations
shows that co-evolutionary interactivity is almost four times as strong a factor
behind IT creativity as the Lamarckian IT strategy.

# Terminology
- Memotype  is the actual information-content of a meme.
- Meme-complex  (sometimes abbreviated memeplex) is a collection or grouping of memes that have evolved into a mutually supportive or symbiotic relationship. Simply put, a meme-complex is a set of ideas that reinforce each other. Meme-complexes are roughly analogous to the symbiotic collection of individual genes that make up the genetic codes of biological organisms. An example of a memeplex would be a religion.
- Memeoid  is a neologism for people who have been taken over by a meme to the extent that their own survival becomes inconsequential. Examples include kamikazes, suicide bombers and cult members who commit mass suicide. The term was apparently coined by H. Keith Henson in "Memes, L5 and the Religion of the Space Colonies," L5 News, 1985 pp. 5-8,  and referenced in the expanded second edition of Richard Dawkins' book The Selfish Gene (p. 330).
- Memetic Equilibrium  refers to the cultural equivalent of species biological equilibrium. It is that which humans strive for in terms of personal value with respect to cultural artefacts and ideas. The term was coined by Christopher diCarlo     in "Problem Solving and Neurotransmission in the Upper Paleolithic (in press).