In Cultural Software: A Theory of Ideology, Jack Balkin argued that memetic processes can explain many of the most familiar features of ideological thought. His theory of “cultural software” maintained that memes form narratives, networks of cultural associations, metaphoric and metonymic models, and a variety of different mental structures. Balkin maintains that the same structures used to generate ideas about free speech or free markets also serve to generate racist beliefs. To Balkin, whether memes become harmful or maladaptive depends on the environmental context in which they exist rather than in any special source or manner to their origination. Balkin describes racist beliefs as “fantasy” memes that become harmful or unjust “ideologies” when diverse peoples come together, as through trade or competition.

Although social scientists such as Max Weber sought to understand and explain religion in terms of a cultural attribute, Richard Dawkins called for a re-analysis of religion in terms of the evolution of self-replicating ideas apart from any resulting biological advantages they might bestow.

As an enthusiastic Darwinian, I have been dissatisfied with explanations that my fellow-enthusiasts have offered for human behaviour. They have tried to look for ‘biological advantages’ in various attributes of human civilization. For instance, tribal religion has been seen as a mechanism for solidifying group identity, valuable for a pack-hunting species whose individuals rely on cooperation to catch large and fast prey. Frequently the evolutionary preconception in terms of which such theories are framed is implicitly group-selectionist, but it is possible to rephrase the theories in terms of orthodox gene selection.
—Richard Dawkins, The Selfish Gene

He argued that the role of key replicator in cultural evolution belongs not to genes, but to memes replicating thought from person to person by means of imitation. These replicators respond to selective pressures that may or may not affect biological reproduction or survival.

In her book The Meme Machine, Susan Blackmore regards religions as particularly tenacious memes. Many of the features common to the most widely practiced religions provide built-in advantages in an evolutionary context, she writes. For example, religions that preach of the value of faith over evidence from everyday experience or reason inoculate societies against many of the most basic tools people commonly use to evaluate their ideas. By linking altruism with religious affiliation, religious memes can proliferate more quickly because people perceive that they can reap societal as well as personal rewards. The longevity of religious memes improves with their documentation in revered religious texts.

Aaron Lynch attributed the robustness of religious memes in human culture to the fact that such memes incorporate multiple modes of meme transmission. Religious memes pass down the generations from parent to child and across a single generation through the meme-exchange of proselytism. Most people will hold the religion taught them by their parents throughout their life. Many religions feature adversarial elements, punishing apostasy, for instance, or demonizing infidels. In Thought Contagion Lynch identifies the memes of transmission in Christianity as especially powerful in scope. Believers view the conversion of non-believers both as a religious duty and as an act of altruism. The promise of heaven to believers and threat of hell to non-believers provide a strong incentive for members to retain their belief. Lynch asserts that belief in the Crucifixion of Jesus in Christianity amplifies each of its other replication advantages through the indebtedness believers have to their Savior for sacrifice on the cross. The image of the crucifixion recurs in religious sacraments, and the proliferation of symbols of the cross in homes and churches potently reinforces the wide array of Christian memes.

Although religious memes have proliferated in human cultures, the modern scientific community has been relatively resistant to religious belief. Robertson (2007) reasoned that if evolution is accelerated in conditions of propagative difficulty, then we would expect to encounter variations of religious memes, established in general populations, addressed to scientific communities. Using a memetic approach, Robertson deconstructed two attempts to privilege religiously held spirituality in scientific discourse. Advantages of a memetic approach as compared to more traditional “modernization” and “supply side” theses in understanding the evolution and propagation of religion were explored.

Opinions differ as to how best to apply the concept of memes within a “proper” disciplinary framework. One view sees memes as providing a useful philosophical perspective with which to examine cultural evolution. Proponents of this view (such as Susan Blackmore and Daniel Dennett) argue that considering cultural developments from a meme’s-eye view—as if memes themselves respond to pressure to maximise their own replication and survival—can lead to useful insights and yield valuable predictions into how culture develops over time. Others such as Bruce Edmonds and Robert Aunger have focused on the need to provide an empirical grounding for memetics to become a useful and respected scientific discipline.

A third approach, described as “radical memetics”, seeks to place memes at the centre of a materialistic theory of mind and of personal identity.

Prominent researchers in evolutionary psychology and anthropology, including Scott Atran, Dan Sperber, Pascal Boyer, John Tooby and others, argue the possibility of incompatibility between modularity of mind and memetics. In their view, minds structure certain communicable aspects of the ideas produced, and these communicable aspects generally trigger or elicit ideas in other minds through inference (to relatively rich structures generated from often low-fidelity input) and not high-fidelity replication or imitation. Atran discusses communication involving religious beliefs as a case in point. In one set of experiments he asked religious people to write down on a piece of paper the meanings of the Ten Commandments. Despite the subjects’ own expectations of consensus, interpretations of the commandments showed wide ranges of variation, with little evidence of consensus. In another experiment, subjects with autism and subjects without autism interpreted ideological and religious sayings (for example, “Let a thousand flowers bloom” or “To everything there is a season”). People with autism showed a significant tendency to closely paraphrase and repeat content from the original statement (for example: “Don’t cut flowers before they bloom”). Controls tended to infer a wider range of cultural meanings with little replicated content (for example: “Go with the flow” or “Everyone should have equal opportunity”). Only the subjects with autism—who lack the degree of inferential capacity normally associated with aspects of theory of mind—came close to functioning as “meme machines”.

In his book The Robot’s Rebellion, Stanovich uses the memes and memeplex concepts to describe a program of cognitive reform that he refers to as a “rebellion”. Specifically, Stanovich argues that the use of memes as a descriptor for cultural units is beneficial because it serves to emphasize transmission and acquisition properties that parallel the study of epidemiology. These properties make salient the sometimes parasitic nature of acquired memes, and as a result individuals should be motivated to reflectively acquire memes using what he calls a “Neurathian bootstrap” process.

An objection to the study of the evolution of memes in genetic terms (although not to the existence of memes) involves a perceived gap in the gene/meme analogy: the cumulative evolution of genes depends on biological selection-pressures neither too great nor too small in relation to mutation-rates. There seems no reason to think that the same balance will exist in the selection pressures on memes.

Luis Benitez-Bribiesca M.D., a critic of memetics, calls the theory a “pseudoscientific dogma” and “a dangerous idea that poses a threat to the serious study of consciousness and cultural evolution”. As a factual criticism, Benitez-Bribiesca points to the lack of a “code script” for memes (analogous to the DNA of genes), and to the excessive instability of the meme mutation mechanism (that of an idea going from one brain to another), which would lead to a low replication accuracy and a high mutation rate, rendering the evolutionary process chaotic.

British political philosopher John Gray has characterized Dawkins’ memetic theory of religion as “nonsense” and “not even a theory… the latest in a succession of ill-judged Darwinian metaphors”, comparable to Intelligent Design in its value as a science.

Another critique comes from semiotic theorists such as Deacon and Kull This view regards the concept of “meme” as a primitivized concept of “sign”. The meme is thus described in memetics as a sign lacking a triadic nature. Semioticians can regard a meme as a “degenerate” sign, which includes only its ability of being copied. Accordingly, in the broadest sense, the objects of copying are memes, whereas the objects of translation and interpretation are signs.

Fracchia and Lewontin regard memetics as reductionist and inadequate. Burman, by contrast, has shown that the misunderstanding that memes are “real” is a result of a popularization based on a confused interpretation of Dawkins’ The Selfish Gene. Instead, for him, the idea of an “infectious idea” can be a useful conceit if used under certain conditions. He explained this in a subsequent discussion regarding his article:

…you can’t take the meme seriously as “a thing that jumps.” You can only ask what insights are derived if we adopt a stance in which we accept jumping as a shortcut to get to the more interesting problem. Memes, in this sense, are a philosophical method; they aren’t a scientific object.

The discipline of memetics, which dates from the mid 1980s, provides an approach to evolutionary models of cultural information transfer based on the concept of the meme. Memeticists have proposed that just as memes function analogously to genes, memetics functions analogously to genetics. Memetics attempts to apply conventional scientific methods (such as those used in population genetics and epidemiology) to explain existing patterns and transmission of cultural ideas.

Principal criticisms of memetics include the claim that memetics ignores established advances in other fields of cultural study, such as sociology, cultural anthropology, cognitive psychology, and social psychology. Questions remain whether or not the meme concept counts as a validly disprovable scientific theory. This view regards memetics as a theory in its infancy: a protoscience to proponents, or a pseudoscience to some detractors.

Richard Dawkins noted the three conditions that must exist for evolution to occur:

variation, or the introduction of new change to existing elements;
heredity or replication, or the capacity to create copies of elements;
differential “fitness”, or the opportunity for one element to be more or less suited to the environment than another.

Dawkins emphasizes that the process of evolution naturally occurs whenever these conditions co-exist, and that evolution does not apply only to organic elements such as genes. He regards memes as also having the properties necessary for evolution, and thus sees meme evolution as not simply analogous to genetic evolution, but as a real phenomenon subject to the laws of natural selection. Dawkins noted that as various ideas pass from one generation to the next, they may either enhance or detract from the survival of the people who obtain those ideas, or influence the survival of the ideas themselves. For example, a certain culture may develop unique designs and methods of tool-making that give it a competitive advantage over another culture. Each tool-design thus acts somewhat similarly to a biological gene in that some populations have it and others do not, and the meme’s function directly affects the presence of the design in future generations. In keeping with the thesis that in evolution one can regard organisms simply as suitable “hosts” for reproducing genes, Dawkins argues that one can view people as “hosts” for replicating memes. Consequently, a successful meme may or may not need to provide any benefit to its host.

Unlike genetic evolution, memetic evolution can show both Darwinian and Lamarckian traits. Cultural memes will have the characteristic of Lamarckian inheritance when a host aspires to replicate the given meme through inference rather than by exactly copying it. Take for example the case of the transmission of a simple skill such as hammering a nail, a skill that a learner imitates from watching a demonstration without necessarily imitating every discrete movement modeled by the teacher in the demonstration, stroke for stroke. Susan Blackmore distinguishes the difference between the two modes of inheritance in the evolution of memes, characterizing the Darwinian mode as “copying the instructions” and the Lamarckian as “copying the product.”

Clusters of memes, or memeplexes (also known as meme complexes or as memecomplexes), such as cultural or political doctrines and systems, may also play a part in the acceptance of new memes. Memeplexes comprise groups of memes that replicate together and coadapt. Memes that fit within a successful memeplex may gain acceptance by “piggybacking” on the success of the memeplex. As an example, John D. Gottsch discusses the transmission, mutation and selection of religious memeplexes and the theistic memes contained. Theistic memes discussed include the “prohibition of aberrant sexual practices such as incest, adultery, homosexuality, bestiality, castration, and religious prostitution”, which may have increased vertical transmission of the parent religious memeplex. Similar memes are thereby included in the majority of religious memeplexes, and harden over time; they become an “inviolable canon” or set of dogmas, eventually finding their way into secular law. This could also be referred to as the propagation of a taboo.

Richard Dawkins initially defined meme as a noun that “conveys the idea of a unit of cultural transmission, or a unit of imitation”. John S. Wilkins retained the notion of meme as a kernel of cultural imitation while emphasizing the meme’s evolutionary aspect, defining the meme as “the least unit of sociocultural information relative to a selection process that has favourable or unfavourable selection bias that exceeds its endogenous tendency to change.” The meme as a unit provides a convenient means of discussing “a piece of thought copied from person to person”, regardless of whether that thought contains others inside it, or forms part of a larger meme. A meme could consist of a single word, or a meme could consist of the entire speech in which that word first occurred. This forms an analogy to the idea of a gene as a single unit of self-replicating information found on the self-replicating chromosome.

While the identification of memes as “units” conveys their nature to replicate as discrete, indivisible entities, it does not imply that thoughts somehow become quantized or that “atomic” ideas exist that cannot be dissected into smaller pieces. A meme has no given size. Susan Blackmore writes that melodies from Beethoven’s symphonies are commonly used to illustrate the difficulty involved in delimiting memes as discrete units. She notes that while the first four notes of Beethoven’s Fifth Symphony (About this sound listen (help·info)) form a meme widely replicated as an independent unit, one can regard the entire symphony as a single meme as well.

The inability to pin an idea or cultural feature to quantifiable key units is widely acknowledged as a problem for memetics. It has been argued however that the traces of memetic processing can be quantified utilizing neuroimaging techniques which measure changes in the connectivity profiles between brain regions.” Blackmore meets such criticism by stating that memes compare with genes in this respect: that while a gene has no particular size, nor can we ascribe every phenotypic feature directly to a particular gene, it has value because it encapsulates that key unit of inherited expression subject to evolutionary pressures. To illustrate, she notes evolution selects for the gene for features such as eye color; it does not select for the individual nucleotide in a strand of DNA. Memes play a comparable role in understanding the evolution of imitated behaviors.

The 1981 book Genes, Mind, and Culture: The Coevolutionary Process by Charles J. Lumsden and E. O. Wilson proposed the theory that genes and culture co-evolve, and that the fundamental biological units of culture must correspond to neuronal networks that function as nodes of semantic memory. They coined their own term, “culturgen”, which did not catch on. Coauthor Wilson later acknowledged the term meme as the best label for the fundamental unit of cultural inheritance in his 1998 book Consilience: The Unity of Knowledge, which elaborates upon the fundamental role of memes in unifying the natural and social sciences.

Proponents theorize that memes may evolve by natural selection in a manner analogous to that of biological evolution. Memes do this through the processes of variation, mutation, competition and inheritance, each of which influence a meme’s reproductive success. Memes spread through the behaviors that they generate in their hosts. Memes that propagate less prolifically may become extinct, while others may survive, spread and (for better or for worse) mutate. Memes that replicate most effectively enjoy more success, and some may replicate effectively even when they prove to be detrimental to the welfare of their hosts.

A field of study called memetics arose in the 1990s to explore the concepts and transmission of memes in terms of an evolutionary model. Criticism from a variety of fronts has challenged the notion that academic study can examine memes empirically. However, developments in neuroimaging may make empirical study possible. Some commentators question the idea that one can meaningfully categorize culture in terms of discrete units. Others, including Dawkins himself, have argued that this usage of the term is the result of a misunderstanding of the original proposal !