3 MEMETIC EVOLUTION | Jack M. Balkin (2024)

3 MEMETIC EVOLUTION

The last chapter offered some analogies between the cultural bricolageof human beings and the evolutionary design of natural selection without sug­gesting that the two are fundamentally the same kind of process. In this chap­ter, I want to take up the question of cultural evolution more directly. I arguethat there is a significant Darwinian mechanism at work in cultural evolution.However, it does not operate through the natural selection of human beings or groups of human beings. What is replicated and selected in cultural evo­lution is not human beings but cultural information and cultural know-how inhuman beings. What is replicated and selected in cultural evolution is culturalsoftware.

Evolution by natural selection requires the “differential survival of repli­cating entities” in a given environment.[1]More specifically, it requires (1)entities that replicate, (2) a source or mechanism of variation that continu­ously provides differences among entities, (3) a means by which variationscan be passed on to future replicants, (4) an environment in which theentities replicate, and (5) different degrees of survival for different entitieswithin the environment. If all five conditions are met, a process of naturalselection results, producing highly complex and differentiated entities over time.[2]

Nothing in this formulation requires that the replicating entities be organic in nature; the first self-replicating entities on this planet may even have been bits of clay, whose slower replication was swamped by the earliest forms of organic life.[3]Hence the principle of natural selection should also apply to units of cultural know-how.

Memes and the Evolution of Cultural Software

Richard Dawkins has coined the wordmeme(rhymes withcream)to describe these units of cultural transmission.Memederives from the Greekmimesis,orimitation, and may also be considered to be a pun on the Englishmemoryandthe Frenchmême(same).[4]

Memes are the building blocks of the cultural software that forms ourapparatus of understanding. Memes are spread from person to person by ob­servation and social learning-either face to face or through media of com­munication like writing, television, or the Internet. Through observation andsocial learning, people internalize and assimilate skills, beliefs, attitudes, andvalues, and these become part of their cultural software. In this way, memesare communicated from mind to mind, are adapted into our cultural software,and become a part of us. Culture is a system of inheritance: we inherit ourcultural software from the people around us, and we pass it on to those whomwe in turn communicate with.[5]

We use memes to understand, yet memes also “use” us, because they areinside us. Our tools of understanding are constructed from and with the skillsand abilities that memes collectively provide. A person is a human being in­habited by memes, a complicated symbiosis of organism and cultural skills.People are complex combinations of their biological inheritance and culturalsoftware, mediated through environmental influences; the information they carry is a combination of their genes and memes.

There are as many different kinds of memes as there are things that canbe transmitted culturally. They include skills, norms, ideas, beliefs, attitudes,values, and other forms of information. Examples of memes (or groups ofmemes) include how to perform a particular dance step; how to build a flyingbuttress; a tune; a political slogan; how to order a meal in a restaurant; andbelief in a divinity. Memes are primarily skills and abilities, but they also includebeliefs about the world, paradigms of research, expectations about appropriateconduct (including the conduct of others), lyrics to songs, and ways of pro­nouncing particular words. Memes encompass all the forms of cultural know­-how that can be passed to others through the various forms of imitation andcommunication.

Linguistic abilities are primary examples of memes, but so, too, are bodilyor kinesthetic skills, for bodily movements are as important to culture as beliefsystems. Body language and dance; athletic, artistic, and craft skills; gestures,expressions, and other bodily movements-all are to some extent transmissibleand hence can constitute memes or complexes of memes. Indeed, imitating andimprovising bodily movements may be one of the most basic forms of culturaltransmission.

Most writers on the subject have thought of memes primarily as beliefs orideas that can be stated in propositional form.[6]This equation is unfortunate.Transmission of culture is primarily transmission of cultural know-how. Thatis one point of the tool metaphor; a tool allows the self to do something.[7]

Much of the richness of cultural life is lost when we insist on reducing skillsto information of a propositional form. Culture does involve information thatcan be stated in propositional form. Yet this information is valuable because itenables. Hence in describing units of cultural transmission, we must understandknowing that,or evenbelieving that,as a special case ofknowing how.[8]

Other writers have argued that representations are the basic units of culturaltransmission. Dan Sperber, for example, distinguishes two basic types of rep­resentations. Mental representations are beliefs, intentions, and preferences.Public representations are signals, utterances, texts, and pictures; they includewhat other writers have called symbolic forms.[9]Sperber’s emphasis on repre­sentations, while helpful, is also incomplete. It does not take into account cog­nitive mechanisms like associations. As Sperber points out, the most importantfact about public representations is that they represent something to someone.The question left unanswered is what allows them to have this representative character. The answer must be in terms of certain cognitive skills that havealso been transmitted to others. These skills cannot be reduced to either beliefs,intentions, or preferences. Hence in addition to representations, a theory ofcultural transmission needs to grant a central place to cognitive skills.

Although beliefs and mental representations are surely part of cultural soft­ware, they are not the whole story. We are more than collections of or recep­tacles for beliefs and representations; we are embodiments of cognitive skillsthat produce and interpret beliefs and representations. Focusing on the cen­trality of cognitive skills helps us remember that culture enables the mind ratherthan simply fills it up.

The standard view of memes as beliefs is remarkably similar to the standardview of ideology as a collection of beliefs. Both conceptions are unduly limited.Understanding ideological phenomena requires us to look at psychological andcognitive mechanisms that produce beliefs. They include informational filters,heuristics, narratives, scripts, associations of meaning, and metaphoric and met­onymic models. These mechanisms are also culturally transmitted and are en­demic to cultures and the beliefs of their members. These forms of cultural software are the major concern of Chapters 8 through 11 of this book.

Our ability to assimilate new cultural software often involves the use of existing cultural know-how and hence employs memes or complexes of memesthat have previously been transmitted and internalized. In order to learn a theorem in physics, for example, a person must already be able to speak alanguage, must already have some knowledge of mathematics, and so on.Memes prepare the way for the absorption of other memes–this progressionis another example of the cumulative nature of conceptual bricolage.

The theory of cultural software distinguishes between a person’s apparatus of understanding and the public representations or symbolic forms that peopleunderstand. Cultural software properly refers to the former and not to thelatter. Cultural software consists of tools of understanding that exist withinminds. Units of cultural transmission can be stored outside minds–in writingsor computer disks, for example–and they can be manifested in utterances and public symbols. But these forms of storage and these manifestations are not cultural software. Nevertheless, the information contained within them canbecome part of a person’s cultural software when it is understood or assimilatedthrough communication or social learning. Although a book does not, strictlyspeaking, contain cultural software, reading a book may add to or alter ourcultural software because we absorb or are influenced by information containedin the book.

This distinction is important because the wordmemehas generally been used more loosely to describe both units of cultural transmission that existoutside of a person’s apparatus of understanding and units of cultural trans­mission that have become elements of that understanding. Thus we can say that a book or a television program contains memes, and that people absorbmemes from watching television or reading books. Memes absorbed in this waycan then become part of a person’s cultural software. So not all memes arecurrently part of some person’s cultural software, although all cultural softwareconsists of complexes of memes that have been assimilated into or initiallycreated by minds.

Memes, like genes, are units of inheritance, but the inheritance is a culturalinheritance. We inherit our genes from our parents. But we can inherit ourmemes from anyone we learn from, imitate, or communicate with. We passour genes on to our children. But we can pass our memes on to anyone wholearns from us, imitates us, or communicates with us.

Evolutionary biologists distinguish between the genetic information codedin genes (the genotype) and the physical or behavioral effects of this coding onan organism in its environment (the phenotype). In the same way, we mustdistinguish between the information coded in memes (the “memotype”) andthe cognitive and behavioral effects that the meme produces in a person (thememetic phenotype). But because we do not yet know precisely how the brainstores information, beliefs, and skills, we can say very little about the memo­type, and we must study memes largely through studying their phenotypiceffects.

Memes must correspond in some way to features of the human brain, butwe do notyetknow exactly how. Each brain is different and may store information in different places. There may be no uniform way that information is stored in different brains, and hence the comparison to chromosomes may be particularly inapt. People whose brains are damaged can sometimes relearn skills using other parts of their brains. Moreover, as Daniel Dennett points out, it would be amazing if “the brain-cell complex that stored the original meme for bifocals in Benjamin Franklin’s brain was the same as, or very similar to, the brain-cell complex that is called upon today to store the meme for bifocals whenever any child in Asia, Africa, or Europe first learns about them–by reading about them, seeing them on television, or noticing them on a parent’s nose.”[10]Nor can we say that the culturally transmissible skill of cello playing corresponds to particular chemical and physical states in the brain coupled with particular configurations of muscles in the hand and arm that are identical for each individual cello player. What makes two examples of a meme in different persons the same is the similarity of the cultural know-how they provide, not the similarity of the ways they are stored in the human body.

Dennett argues that what is preserved in cultural transmission is cultural information in a media-neutral, language-neutral sense.[11]One need not make this assumption, however. First, as media theory reminds us, the medium of transmission may be an important part of the message conveyed. Second, the idea of a media-neutral content of information presumes that social commu­nication essentially involves coding and decoding an identical message. Yet social learning and communication of bodily skills may in fact be much more complicated than this.

For example, the process of advertising does not involve merely a coding of information that is designed to be decoded. Rather than simply convey in­formation, it tries to create similar preferences in different people. Much hu­man communication requires the parties to infer and supplement what is being conveyed rather than simply uncoding it.[12]Finally, the metaphor of coding and decoding an identical media-neutral message is particularly unhelpful in de­scribing how someone teaches another to kick a football, shape pottery, or play a musical instrument. In such cases, we should rather say that the mind and body, through social learning, create their own individual skills similar to but not necessarily identical to those perceived in others. This is a form of repli­cation, to be sure, but decoding is not the appropriate metaphor.[13]

Genes usually replicate in complexes or groups, called genomes. It is likely that culture is also transmitted in complexes of memes, or memomes. Before the discovery of the biochemical vehicles of genetic inheritance, it was difficult to determine where genes began or ended. Scientists had to make inferences about the boundaries between different genes from their phenotypic effects on an organism’s physical features and behavior. Often (as in the case of blue eyes) a phenotypic effect is the result not of a single gene but of a combination ofgenes, but scientists could not determine this until they understood the bio­chemical basis of inheritance. Because we do not know precisely what biologicalvehicles carry memes, it is hard to separate the meme from the memome inthe way that we can now separate some genes from their genomes.

These limitations in our knowledge raise a problem of demarcation anddivision. Is Beethoven’s Fifth Symphony a single meme, or does the four-notemotto that begins the piece qualify by itself? The solution to this difficulty isentirely pragmatic, as it is in the case of genes. Multiple traits are often passedtogether from parent to offspring–for example, a certain shape of nose and acertain eye color–but we can say that the gene is the smallest unit of geneticinformation that can be and is repeatedly transmitted more or less intact. In asimilar spirit, we can say that memes are the smallest units of cultural skills or information “that can replicate themselves withreliability and fecundity.”[14]

This solution does not eliminate all difficulties. Daniel Dennett argues that that the notes D-F#-A do not constitute a meme, while the theme from the slow movement of Beethoven’s Seventh Symphony is a meme. Just as a single codon of DNA like C-G-A (coding the amino acid arginine) is “too small” to be a gene, Dennett believes that the effects of the notes D-F#-A are insufficiently individual to count as a meme. A “three nucleotide phrase does not count as a gene for the same reason that you can’t copyright a three-note phrase: it is not enough to make a melody.”[15]

Dennett’s argument misses an important difference between genetic trans­mission and cultural transmission. The biochemical vehicles of genetic trans­mission place lower limits on the size of the units of transmission. Athree-nucleotide phrase cannot be a gene because of the biological structure ofgenes. But cultural transmission works very differently. A skill or a piece ofinformation can be a building block of other, larger elements and yet also operate as a meme in its own right in other contexts, as long as it has someindependent memorizable meaning to an audience. Moreover, the length ofthe sequence is not the only factor. The cultural expectations of audiences(which include their own preexisting cultural software) help determine what isreliably memorable and what is not. Thus, the musical phrase F#-E-D playedat moderate tempo represents the song “Three Blind Mice” to people livingin certain cultures. Because these three notes played slowly call that song tomind, they can serve as a symbol of the entire piece. And a symbol-somethingthat stands for something else to someone in some context-is a particularlysalient example of a meme. Note, however, that these three notes played slowlyalso begin the second subject in the first movement of Tchaikovsky’sPathetiqueSymphony.”[16]The first F#-E-D is a meme, but the second (at least currently) is not.[17]

We now see why Dennett’s analogy to copyright law is mistaken. The reason why the law does not permit short phrases to be copyrighted has nothingto do with the phrase’s inability to have significance or to be memorized reli­ably and repeatedly. It stems from the fear that the owners of the copyrightcould demand royalties for each and every use, thus stifling creativity. Protec­tion is denied not because short phrases cannot be memes but because theycan be memes. Because units of cultural transmission can act both as indepen­dent units of meaning and as building blocks for other units, the law does notallow the very smallest units to become intellectual property; excessive propertyprotections may block larger, socially beneficial constructions.[18]

This example raises one of many important differences between biological and cultural evolution. Memetic evolution may be a process of natural selection,but it does not necessarily occur in exactly the same way as biological evolution,or use precisely analogous structures and techniques. Many features of biolog­ical evolution may result from the particular requirements of biological repli­cation and designoid structures arising earlier in the development of life onthis planet. For example, biological evolution on Earth makes use of DNA andRNA, alleles and codons, because of the particular way that life originallyformed and was able to reproduce itself. There may have been many differentpossible biochemical structures of biological reproduction and evolution, but organisms on this planet hit upon a particular one and successively built uponit. The structures that we discover in genetic evolution may not be in any sensenecessary to evolution but may simply be the ones that evolved historically totransmit genetic information-given the constraints of the particular biological organisms that were first able to carry and reproduce this information throughtheir own growth and reproduction. It does not follow that all forms of evo­lution through natural selection require analogous structures of transmissionand evolution.

We should use the concepts of biological evolution to the extent that theycan serve as a useful heuristic to understanding cultural evolution. We can startwith a model of evolution that we already know something about and use it asour point of departure for studying other forms. But if we rely too heavily onbiological analogies, we will inevitably be misled, because biological evolutionis only one possible form of evolutionary development. We must always be on the lookout for disanalogies. Indeed, discovering these disanalogies often is as helpful in understanding cultural evolution as discovering analogies.

Memes as Populations

Like genes, memes are self-replicating entities, but the environment in whichthey replicate consists of human minds and the places for external informationstorage that humans have devised. At any point in time there is a “meme pool”of memes competing for survival in the environment of human minds, just as there is a gene pool that competes in its environment. No two human beings have the same memes; there are no identical cultural twins. Every human being is a unique individual, and not simply the replication of a cultural template.

Both the study of cultural evolution and the study of genetic evolution by natural selection employ what Ernst Mayr has called “population thinking.” Species are populations of slightly different organisms that carry slightly dif­ferent combinations of genes. The frequency of these genes in the overall pop­ulation changes depending on how organisms interact with the environment. Individuals with genes favored by their environment have better chances to survive and produce more offspring. Over time, the species evolves because of the changing composition of its gene pool. Viewing species as populations means that species are not essential, unchanging types, and members of a spe­cies are not imperfect examples formed from a standard template. “There is no `typical’ individual,” Mayr points out, “and mean values are abstractions.” Variation is not only characteristic of individuals, it is essential to the forces of change. As Mayr puts it, “he who does not understand the uniqueness of in­

dividuals is unable to understand the working of natural selection.[19]A similar analysis applies in the world of culture. Each person is constitutedby apopulation of memes-her cultural software-and the entire population of human beings represents an even larger population of memes. We can think of cultures, subcultures, and interpretive communities as populations of partly similar, partly different memes reflecting partly similar, partly different cultural software in individuals. Cultures, subcultures, and interpretive communities are neither natural nor supraindividual entities; they are effects of or useful ab­stractions from the slightly different cultural software of their members. Cul­tures have conventions and institutions that help to reproduce the cultural software of their members. Yet these coordinated behaviors are also the effects of the similar but slightly different cultural skills of their members. The cultural and the individual thus tend to fade into each other: what is cultural consists of widely spread and long-lasting memetic features of individual members of the culture, just as the species consists of the widely spread and long-lasting genetic traits of individual members of the species.[20]

We can reinterpret the concept of a cultural tradition in these terms. Thereare two ways of understanding a tradition: one synchronic and the other dia­chronic. These two visions of tradition correspond roughly to two differentways of thinking about species-synchronically, as a population of relativelysimilar individuals with relatively similar genes existing at a given point in time,and diachronically, as a line of genetic descent.

Viewed synchronically, a tradition is a set of ways of thinking through which people understand and live at a particular moment in their lives. Traditions involve populations of relatively similar memes that constitute thepeople who live within those traditions. A tradition produces a particular per­spective or horizon-the way of seeing and understanding the world that makesuse of the cultural software that one has. The shared perspective among themembers of the tradition is due to the similarity of their tools of understanding.

Diachronically, a tradition is an ongoing process in which members inhabitone particular, though not necessarily privileged, moment. The tradition isreproduced in successive generations, but it changes over time and may have transformed itself considerably in the process. What allows people to think ofthemselves as “traditional” Jews, for example, is not the belief that they are doing exactly what people did 3,000 years ago in ancient Israel.[21]Rather, it isthe belief that there is a genealogical continuity between what others who calledthemselves Jews did in the past and what one is doing now. This approachviews tradition as a line of memetic descent, in which the memes possessed bythe members of the present interpretive community can be seen as linkedthrough a chain of communication and education with the memes of earliermembers. Because memetic evolution occurs much more rapidly than geneticevolution, traditions may evolve and change quickly, and over time many oftheir core beliefs, practices, and rituals may be displaced, despite our ability totrace a transhistorical continuity of transmission.

The environment for memes consists of human minds and methods ofmemory storage. There is a limited number of minds in a geographical area, in a particular culture, or in the world. Each mind has limited time for sociallearning and limited information-storage capacity. Memorization or achieve­ment of a skill not only requires exposure to cultural transmission; it also re­quires conversion from short-term memory to long-term memory. Repeatedexposure and practice may be necessary if the skill is to endure and becomesecond nature.[22]

Moreover, even though memes can eventually be stored outside of minds,they still need the intervention of minds at crucial points for their replicationand continued survival.[23]Hence human minds create a bottleneck for the rep­lication and storage of cultural skills and information. Memes must competefor available space. Variation among memes causes different rates of survivaland propagation. Memetic competition for available space in the minds of hu­man beings creates gradual changes in the population of memes in a particulargeographical area, or in a particular culture or subculture. If the survival rates differ enough, particular skills may become extinct or die out. Languages, forexample, die out when insufficient numbers of speakers are available to repro­duce them. The same is true with bits of information or bodily skills. If every­one forgets how to do the rhumba (and no external records of how to perform it remain), the rhumba goes out of existence, although something like it maybe invented in the future.

Indeed, not only is there competition among memes and meme complexesfor instantiation in human minds, there is competition within each human mindfor those memes that are most easily remembered, repeatedly transmitted, andfrequently employed. People use some skills more frequently than others andforget some things more easily than others. They bring some skills to bearmore often and other skills less often. They develop some skills more and otherskills less. They think and talk about some things more frequently and othersless so. We might say, loosely speaking, that a human mind is a population ofcompeting memes that exists in a larger population of competing memes calleda culture, a subculture, or an interpretive community.

One of the most important parts of the environment that memes face areother memes in the meme pool and the behaviors and beliefs they produce.Thus memes not only compete, but they also must adapt to the existence ofother memes and may even benefit from or depend on other memes for theircontinued survival. Many memes in human culture survive and propagate onlybecause human beings already have internalized and mastered certain linguisticskills and vast quantities of information and cultural know-how. Previous ed­ucation is often necessary to comprehend, recall and utilize newer skills and information. Some memes, like some genes, can even be coadaptive, so thattheymutually assist in each other’s survival.[24]

Memetic Variation

An important difference between cultural and genetic evolution concerns thefrequency of variation. Genes usually make very good copies of themselves;mutations are a relatively rare occurrence. The same is not true in the worldof culture. Cultural transmission requires communication, imitation, or someother form of social learning. The copies produced by this process are rarelyidentical to the original. Misunderstandings occur, or, more frequently, partialunderstandings occur that are good enough for one purpose but not for an­other, unforeseen purpose. Skills require practice to be perfected; the need topractice them means that the earlier attempts will be inartful and that laterattempts will draw heavily on the recipients’ own personality and abilities. Justas no two people dance, cook, or play the cello in precisely the same way, notwo people understand social conventions or situations the same way. As they pass these skills and understandings onto others, further change occurs.[25]

Memetic mutuation occurs not only because of misunderstanding or be­cause old signs are inserted into new contexts. It also occurs because of innovation. Human beings are not passive receptors of memes; they are active processors and recombiners of the cultural messages and skills they receive from others.

First, human minds combine and adjust the memes they receive with thosethey already possess.[26]For example, people have filtering mechanisms for re­ceiving new information; they may discount information if it conflicts toogreatly with what they already believe.[27]Similarly, the theory of cognitive dis­sonance suggests that people may reconfigure new ideas and understandings toachieve intellectual coherence with their existing beliefs or to preserve theirsense of themselves.[28]People also create new memes when they learn through trial and error.

Second, individuals are creative. They modify skills, combine information,draw inferences, and stretch conventions. To be sure, people always do thesethings by making use of the cultural software they already possess. But this factdoes not make their activity any less creative; indeed, their cultural softwareenables their creativity by providing thought with a necessary framework for problem solving and innovation. In short, human beings are not simply Xerox machines for their memes; they are also incubators for new memes, as well asmaster chefs who combine old memes to create new memetic recipes. We sendour newly created memes out into the world, where they are received, assim­ilated, adjusted, recombined, and modified by countless other minds, each cre­ative like our own. The power of human reason, made possible in part by thememes we possess, is also the power to mutate those memes and create some­thing new from something old. We are not simply the inheritors of a zealouslyguarded patrimony but entrepreneurial producers of new cultural software,which will help constitute future generations of human beings. So the story ofmemetic evolution is neither the story of our slavery to memes nor the storyof how human reason enables us to break free of this slavery. Rather, it is astory of the collective creation of human reason, a story of powers of height­ened creativity made possible by previous memetic infestations, a story of free­dom mixed with, and paradoxically made possible by, constraint.

Because human beings are creative and combinatory, the path of cultural evolution must necessarily be different from that of genetic evolution. In theOrigin of Species,Darwinused the metaphor of the branches of a tree to describethe basic trajectory of evolution.[29]Life on Earth, he argued, has a single origin.Different species diverge from this root at different times, further subdividinginto new species. This topology means that as species evolve, they separate intoever new forms, and the proliferating branches never recombine. But the his­tory of cultural development is quite different. Cultures do tend to divergebecause of geographic isolation or disciplinary specialization, but later people often borrow from other cultures to supplement their own. For example, American cuisine-which includes such delicacies as deep-dish pizza, hamburgers,and chop suey-borrowed from other cultures to create dishes that did notoriginally appear in those cultures. (Though to be sure, the spread of Americanculture in the twentieth century means that now one may indeed be able toget hamburgers in Hamburg, deep-dish pizza in Rome, and chop suey in HongKong–yet another example of cultural recombination.) A similar point appliesto technological development. Inventors often look for solutions by lifting ideasfrom widely divergent cultural sources: the use of computer punch cards tostore information, for example, was inspired by the Jacquard loom, which wasin turn based on the earlier technology for constructing automated pipe or­gans.[30]This sort of cultural borrowing is yet another example of the bricolage described earlier. In sum, one of the most important distinctions between ge­netic and cultural evolution is that while biological lineages increasingly di­verge, cultural lineages often recombine.[31]

A second important distinction concerns the mechanisms of replication andsurvival. As noted earlier, in the cultural world, transformation is the rule andexactcopyingis the exception. Moreover, much cultural transmission is not aprocess of coding and decoding an identical message; it may involve creatingsimilar cognitive skills through imitation and inference from salient examples. An evolutionary theory of culture based on the differential survival of replicat­ing entities must take these facts into account. If memes are constantly beingtransformed as they spread, the mechanism of differential survival must operatedifferently in the cultural and biological worlds.

The survival of cultural software does not depend solely on different ratesof attractiveness or acceptance by human minds. Human beings inevitably transform what they receive from others; even if I like what I see or hear, it will be changed when I pass it on to others. This presents a real problem formemetic survival: if transformations were purely random, they would eventuallydestroy the identity of what spreads. If people randomly transformed differentelements of an original story each time it was told, after a time there would benot a single version that was widespread but a random distribution of many different stories. For memes to be successful replicators, it is not enough thatthey have descendants; they must also have sufficiently similar descendants.

A particular kind of cultural software will not become widespread in a pop­ulation unless its transformations are systematically biased in particular direc­tions, or tend to converge on a central set of features. Put another way, if aparticular kind of cultural software does become widespread, it is probablybecause some types of creative change or transformation of that software aremore likely than others. What becomes widespread is not only what resists transformation but what gets transformed, in roughly the same way by manydifferent people.[32]

Human psychology and cultural factors play a central role in these subse­quent transformations. For example, people are more likely to retell those el­ements of a story that are most salient and easily memorized; they are morelikely to forget or transform others. In this way psychological properties ofmemory and relevance determine how some parts of stories are retained, howother parts get transformed, and how those transformations converge. Trans­formations may also converge because of the force of existing cultural expec­tations. A story with an inconclusive ending will probably gain a happy or asad ending if it is repeated often enough. Here multiple transformations maylead to the spread of two different stories with different endings. Conversely, the process of transformation may tend to combine different varieties of cul­tural software. Two or more different stories may eventually converge into asingle story because successive recountings of each get transformed toward acommon version.

In describing the spread and success of cultural software, therefore, we mustconsider effects on the “demand” side (what kinds of memes are most attrac­tive, salient or useful to other minds) and on the “supply” side (what kinds oftransformations memes will undergo as they are communicated to otherminds). In the biological world, the problem of guaranteeing similarity among descendants is not very great because the biochemical mechanisms of copyingtend to be fairly accurate. Hence the most important determinant of repro­ductive success is selection by the outside environment. But in the culturalworld, a meme must contend with both the outer environment of other mindsthat might be receptive to it, and the inner environment of the mind thatpropagates and transforms the meme. It must survive in both environments,and it must survive in ways that retain its commonality with other memes.

Problems of Transmission

In order for memes to replicate, they must be embodied in some vehicle. Peo­ple are the most important vehicles for memes, but books, records, and com­puter disks also serve as vehicles for cultural replication. Technology itself canserve as a meme vehicle. The very existence of a wheel suggests to us the factthat such a tool can be created, how to create it, and how to use it.[33]Theamount of information technologies convey about themselves is necessarily lim­ited, however, especially as the technologies get more complex.

If all of a meme’s physical embodiments (including all human memorystorage) are destroyed, the meme becomes extinct, although something like itcan be invented anew. The durability of a particular vehicle does not necessarilyguarantee reproductive success over time. Many insect species have existed for millions of years, even though the lives of individual insects are comparativelyshort. Rather, it is more important to produce many copies than to ensure thatall the copies survive for long periods of time.[34]

Cultural evolution is not possible until there are sufficiently powerful in­formation-processing devices capable of storing information and reliably trans­mitting it to or replicating it in other information-processing devices. Animalshave rudimentary abilities to produce culture and pass it along to their off­spring. Animals can learn skills and imitate movements, and some even haverudimentary semiotic and linguistic skills.[35]Birds can imitate songs and trans­mit them from generation to generation, and these songs can even mutate over time.[36]But if a pigeon sees a copy of Shakespeare’sHamlet,it cannot assimilatethe memes contained in that play. Even if an animal could memorize a partic­ular skill or particular information, the skill or information dies with the animalif it cannot transmit its mastery reliably to others. Fecundity, transmissibility,and longevity-three essential requirements for a process of natural selection ­were not sufficiently present before the evolution of humankind.

Once comparatively large-brained human beings arrived on the scene, andinvented language, however, memetic evolution really took off.[37]Fecundity wasgreatly increased because many different kinds of memes could be transmittedto many people at once through vocal communication, observation, and imi­tation. The memes involved in linguistic ability greatly enabled the trans­mission, processing, and storage of other memes, which in turn enabled thetransmission, processing, and storage of still others. Longevity was enhancedbecause even though a particular person died, her information could be passedon to others. This environment was still somewhat inhospitable for memesbecause it relied so heavily on human memory for storage and on human speechand movement for transmission. The next great advance in memetic fecundity,transmissibility, and longevity was the invention of external forms of infor­mation storage: first through writing, then by means of printing presses, and in our own day through the use of digital computers. With the invention ofwriting it became possible for the ideas of an ancient scholar like Plato tosurvive into this century without having to be fully memorized by an unbrokenchain of individual memories. Indeed, to the extent that external forms of in­formation storage are more durable than human memory, there may be somecomparative advantage for memes to convert human memories into these moredurable forms. It is this possibility that underlies Dennett’s wry suggestion thata “scholar is just a library’s way of making another library.”[38]

The development of extrinsic sources of information storage is important for another reason. As we have seen, the human mind is a natural bottleneck for me­metic evolution, because memes usually must reside in a human mind beforethey can be transmitted to others. The scarcity of human minds is an important element of the natural selection of memes. Increase in the brute number of human beings eases this bottleneck to some degree: for example, it makes possible(but by no means guarantees) a flowering of knowledge that might not have beenpossible in earlier times. Nevertheless, the bottleneck remains.

On the other hand, if computers become sufficiently developed, humanmediation and incubation of memes may become increasingly unnecessary. Tobegin with, after a certain level of technological innovation is reached, it be­comes possible for information to propagate without its contents being directlystored or understoodby anyhuman mind. Whenever computers communicatewith each other or copy files, for example, information is propagated whetheror not it is ever accessed by a human mind. A human mind is still necessaryto design, program, and repair the computers, but it is not necessary for ahuman mind to think all the information the computers contain. Eventually, it is possible that more and more features of maintenance, programming, anddesign could be left to computers themselves. A rudimentary example is thecurrent use of computers to design computer chips.

The creation of new propagation and incubation devices might ease thebottleneck of memetic growth and thus drastically change the course of me­metic evolution. Indeed, it is quite possible that some memes may presently find computers a more hospitable environment for development than the hu­man minds that their ancestors originally inhabited (and spurred on to con­struct computers). Of course, the features that benefit a meme’s survival andpropagation in a computer’s memory banks may be quite different from whatguarantees its survival in a human brain or on a piece of paper. Hence memesthat successfully inhabit computers may evolve differently and possess some­what different features from those of their human-dwelling cousins.

In order to reproduce successfully, memes must be able to transmit them­selves from one mind to another. Originally, this must have presented an enor­mous hurdle. One cannot simply copy cultural software onto a brain as onewould load software from one IBM-compatible computer to another. Copyingsoftware is easy on these computers because each has identical physical struc­tures for reading and coding data and an identical hard-wired machine lan­guage. By contrast, copying and running software on computers with differentand proprietary hardware is actually a fairly difficult task. At the beginning ofthe personal computer revolution in the 1970s and early 1980s, for example,there were literally dozens of incompatible computer designs, none of whichcould load or run one another’s software. Many computer manufacturers even­tually went bankrupt because their machines were not 100 percent IBM com­patible. Our image of computer software as something that can be easilypopped out of one computer and into another is really the result of competitivepressures that weeded out most designs for personal computers until the IBMand Apple designs achieved market dominance in the mid-1980s.Human beings are decidedly not like mass-produced IBM computers. Thephysical structure of each person’s brain is different, a product of both geneticinheritance and subsequent development. The mental capabilities of humanbeings are more like a proliferation of different proprietary architectures, eachwith its own unique features. If we want different kinds of computers to talkto each other, we must create a program on each that can accommodate itsarchitectural idiosyncracies. Each such program creates on the computer a “vir­tual machine” of software and hardware that can read and understand commoninstructions, and thus can speak a common language.[39]

Because each brain’s structured capacities are different, memetic exchangemust occur through a mode of transmission that is, as Daniel Dennett puts it,”social, highly context-sensitive, and to some degree self-organizing and self-­correcting.” Put another way, if human beings can transmit and share cultural software, it must be due to the differential survival of memes that have a highdegree of adaptability and tolerance for different mental environments.[40]Atthe same time, there must be some degree of commonality in the basic cog­nitive and linguistic apparatus of human beings to allow such hardy meme­skills to have developed in the first place. The scope and extent of thisuniversality is the well-traveled terrain of the debate between Chomskyites andtheir opponents.

These transmission skills come in several varieties, including learning byimitation, through positive or negative reinforcement, and through natural lan­guage.[41]Once these skills exist even at the most rudimentary levels in brainsthat are big enough for large numbers of memes to inhabit, the process ofmemetic evolution takes off, building its own “information superhighway”from previous meme-skills and facilitating the replication of more and morememes. Thus, just as human beings change their environment to make it morehospitable, memes without intention or plan develop and combine to create a more hospitable environment for themselves both in human brains and in ex­trahuman information-storage devices. The development of the first hardymemes that could create the virtual machines that facilitated transmission was itself the result of a process of natural selection. Memes that were able to do sosuccessfully spread, while those that could not failed to take hold in thememe pool. Subsequently, other memes could and did take advantage of thisnewly fertile ground.

Memes as Filters

As I noted earlier, most theorists who discuss units of cultural transmissionhave focused on meme-beliefs, rather than meme-skills. This bias is similar tothe general tendency to assimilate all features of ideologies to beliefs. Yet manyof the most important forms of cultural software–and particularly the mostimportant for the study of ideological phenomena–are skills or cognitive struc­turing mechanisms that cannot be reduced to propositional beliefs. A goodexample of such a meme-skill is a filtering mechanism.

It is clear that beliefs can act as filters; an example is the notion that oneshouldn’t believe anything printed in a particular publication or spoken by aparticular politician.[42]But filters do not have to exist in the form of proposi­tional beliefs. Many cognitive mechanisms, including prejudices, narrativestructures, metaphoric models, and metonymic associations, act like filters.They let in ideas that conform to particular patterns of thought while rejectingthose that do not. Psychologists have also discovered a series of heuristic mech­anisms that people use to search for information and other mechanisms that people use to assess and discount information contrary to what they already believe.[43]These mechanisms also filter experience. Alternatively, cognitivemechanisms can actively adjust and shape new social experience so that it ap­pears to conform to existing structures of thought and belief. Mechanisms ofcognitive-dissonance reduction seem to work in this way.[44]

We can put this point more generally. Many ideological effects are pro­duced by memes that act as cognitive filters. There are many different waysthat our cultural software can do this, and the study of how it does so is a largepart of the study of ideological effects. Memes that act as cognitive filters be­come part of the environment for new memes that seek entry into humanminds. These filtering memes help the mind to accept some meme candidatesand reject others, or help adjust and reconfigure incoming memes to existingpatterns of thought. Hence these meme filters are part of the mechanisms ofnatural selection that occur within each individual human mind. All otherthings being equal, memes that can most easily break through or accommodatethemselves to the filtering mechanisms of an individual human mind are morelikely to find room in the limited memory space available in that mind.

Moreover, because filtering memes help determine which memes are ac­cepted in human minds and which are not, they are important mechanisms ofnatural selection of beliefs and skills within cultures, and indeed, across theentire population of human minds. All other things being equal, those memesthat can most easily break through or accommodate themselves to the filteringmechanisms of people’s minds will, over time, be more represented in thememe pool of a given population, culture, or subculture.

In sum, meme-filters help explain how human beliefs-and hence the ide­ological effects of those beliefs-develop and spread differentially. The idea ofa meme-as-cognitive-filter links the study of memetics or cultural evolution tothe theory of ideology.

But if meme-filters are an important source of ideological effects, and ifthey are part and parcel of the natural selection of memes in the ecology ofhuman minds, how are they themselves selected for in the first place? Whywould human minds develop meme-filters as part of their cultural software?

The most important fact about information is that there is too much of it.Finite human minds need ways of taming the Heracl*tean flux of experience.Thus filtering, organizing, and structuring information is a positive good, andmemes that act as filters naturally arise to fill this need. Like all evolutionaryinnovations, such filtering mechanisms do not have to be perfectly designed.They need only be good enough for the purpose at hand and may have allsorts of unforeseen and unforeseeable side effects. This means that some mech­anisms of filtering may be harmless or even quite helpful in some contexts butharmful, prejudicial, and unjust in others.

Our memes filter, organize, and structure social experience. They providekey components of the environment in which new memes will grow, develop,propagate, and perish. These filters and structures arise along with the prolif­eration of information. Hence increasing the amount of available informationdoes not necessarily increase knowledge or understanding. It does not resultin a person’s being well rounded or well read, having an open mind or beingreceptive to new ideas. Indeed, under certain circ*mstances it can have precisely the opposite effects.

Encountering an explosion of information can foster closed-mindedness,because too many competing sources of information produce the potential forconfusion. The flood of conflicting information creates a suitable environmentfor breeding ever new forms of memetic filters that harness the flow and shutout many different kinds of information. Some of these filters may includemechanisms that hide their own biases and limitations, because this tends toincrease their success at propagation.

Thus we should not necessarily assume that the proliferation of new infor­mation sources and the coming together of many different cultures will producethe end of ideological conflict. Rather, the widespread availability of informa­tion and the collision of many different cultures and language games may infact produce more narrowness of thinking, more inflexibility, and more intol­erance, whether between ethnicities or between academic disciplines.

The development of memetic filters creates new bottlenecks for the prop­agation of memes. Memes that can break through or get around these filtershave greater chances to spread in a population of minds. Thus complexes ofmemes develop means of evading filters: examples are the development of flashygraphics, large type, or loud music in advertising to attract an audience’s at­tention. In response, new forms of filtering arise to keep pace. The result is asort of “arms race” between memes seeking places in human minds and the filters designed to winnow them out.[45]

Eventually, filtering and devices to get around these filters start to exist in symbiosis, so that it becomes difficult to distinguish between what is filteringand what is promotion designed to evade filtering. Advertising the status of anauthor, for example (through institutional affiliation or kudos on the dustjacket), can be used to signal that the work is worth reading, but this signal isalso adjusted to known filtering mechanisms for deciding which works to read.Signals, in other words, are the flip side of filters. They are devices used toadvertise quality or desirability to a potential audience so as get past informa­tional filters. And as Dennett observes, “`Blind refereeing,’ the proliferationof specialized journals, book reviews, reviews of book reviews, and compilationsof `classic works’” can be seen both as filtering devices and as means to getthrough these devices and into human minds.[46]

Memes as Viruses

Because cultural software is transmitted from person to person, there is a nat­ural analogy between cultural software and viruses. The human mind is sus­ceptible to memes just as the human body is susceptible to infection fromparticular viruses.[47]The study of cultural evolution is a study of comparative epidemiology. Some memes are more contagious, or “catching,” than othersin a population and thus spread more widely and successfully.[48]

The metaphor of susceptibility to viruses helps us understand the deepconnections between the power of human intelligence and its vulnerabilities.Human beings are more susceptible to many more kinds of memes than, say,pigeons, precisely because they have a greater intelligence.[49]All forms of hu­man understanding involve susceptibility to memetic invasion. Human beingsare vulnerable to memetic infection precisely because they are so well devel­oped as meme reception machines. Moreover, much of this infection does notinvolve someone intentionally sending a message to a recipient. We receive memes when we observe another person’s behavior or dress or when childrenpick up ideas or behaviors from their parents, teachers, or schoolmates. Just aschildren easily contract all sorts of diseases, they are particularly susceptible tomemetic “infections” in all sorts of unintended ways. That is one reason why parents are so particular about what their children are exposed to.

People’s susceptibility to memes varies with the skills that they already possess. Our existing cultural software shapes what is salient, interesting, andhence what is easily communicated and easily absorbed. Although childrenlearn all sorts of words that make their parents cringe, they are relativelyimmune from discussions of fluid dynamics. I am susceptible to memes in En­glish but relatively immune to those in Urdu, because I do not speak that lan­guage. Lawyers who practice bankruptcy law are more susceptible thanlaypersons to remembering and being affected by discussions of recent bank­ruptcy decisions.

Taking the metaphor of disease one step further, we can describe a contin­uum between two types of cultural infections, the endemic and the epidemic.Some cultural software is transmitted persistently over generations of individ­uals and through many different human cultures; it is endemic to a particularculture or to human thought generally. Other forms of cultural software spreadrapidly from person to person, like advertising slogans and fashions. These memes are comparable to epidemics.[50]

The distinction between epidemic and endemic cultural software is quite important for the study of ideology. Many of the cognitive mechanisms thatproduce ideological effects in human thought are endemic rather than epi­demic. Narratives, networks of association, metaphors, and metonymic modelsare transmitted widely and persistently. Moreover, once in place, these endemic forms of cultural software provide the environment in which epidemic cognitivestructures and beliefs can thrive. The study of ideology is the study both ofendemic cognitive structures and of epidemic changes in beliefs and symbols.

Racist thought can be both endemic and epidemic. Racist thinking occa­sionally sweeps from person to person like a dangerous virus. Yet equally im­portant to understanding the phenomenon of racism are more basic cognitive structures-for example, historical associations of white and black with con­trasting positive and negative stereotypes. These networks of association areendemic-they are deeply embedded and widely reproduced in many cultures. They prepare the ground for the development and spread of racist beliefs.

Memes as Symbionts

The account of cultural evolution that I have been developing suggests thatnot only do people have ideas, but ideas have people. Memes “use” people forthe purpose of their own propagation. We should not understand such an­thropomorphic language literally: memes no more than genes have wants, de­sires, purposes, or interests. Rather, this is merely a shorthand way of describing how natural selection works on units of cultural transmission.

This approach removes the need to explain human cultural developmentand proliferation solely in terms of its survival advantages for human beings.To the contrary, we may assume that much cultural development is largelyirrelevant to human survival in the short term, although it may have manyprofound and unexpected long-term effects. Memes do not necessarily repro­duce and propagate because this process confers an evolutionary advantage onhuman beings (although this may in fact occur). Rather, they survive, repro­duce, and propagate because it advantages them.Thus, we can think about cultural software as a kind of symbiont. A sym­biont is an organism that lives inside or attached to another organism. Thelatter organism is called the host, the symbiont is called the guest. We canthink of cultural software as a kind of informational symbiont. Under this anal­ogy, our bodies (and our brains) are the biological hosts for cultural software.

Roughly speaking, we can divide symbiosis into three kinds. In the firstcase, mutualism, the host and guest enhance each other’s reproductive fitness.A second case, commensalism, occurs when the symbiosis benefits the guest’sreproductive fitness with little or no cost to the host. The third and mostfamiliar case is parasitism. A parasite is a guest that benefits at the expense ofthe reproductive fitness of the host.[51]The natural world does not divide up asneatly as these categories would suggest. It is quite possible for a guest to helpthe host in some ways, harm it in others, and be neutral in still others.

Memes are like symbionts that alter the behavior of their hosts, much asthe rabies virus alters the behavior of a dog by making it more aggressive,increasing its salivation, and preventing it from swallowing.[52]Just as the genesin the rabies virus make use of the host to spread their genetic information,memes use their hosts to spread their own memetic information. The rabiesvirus is a parasite because it increases its own reproductive success at the ex­pense of the dog’s. However, the survival and spread of memes can either beadvantageous, indifferent, or in opposition to the reproductive fitness of thehost-memes can be mutualist, commensalist, or parasitic.

There are two important limitations to the comparison between memesand biological symbionts. First, the union of biological capabilities and culturalsoftware creates a new kind of entity, a person. This is not true in the case ofa dog infected with a rabies virus. It is still a dog. Second, this new entity, theperson, has new interests independent of the reproductive success of the bio­logical host. People have interests in both senses of that word: there are thingsthat they are interested in (that is, they have preferences, desires, and values)and things that are in their interest. These categories can be further dividedinto long- and short-term interests, and the various kinds of interests can con­flict with each other.

Most living things have relatively uncomplicated interests in eating, sur­viving, and reproducing. Because people combine genes and memes, their ex­istence is more complicated. Their interests constantly develop, change, andconflict during the course of their lives, and they often have no idea preciselywhat they want or exactly what actions they should take. Indeed, we mightdefine a person as an entity that is continually at a loss for what to do.

We must therefore distinguish between what advantages a person’s interests(in the various senses of that word) and what advantages the reproductive suc­cess of his or her genes. Memes can help one while hurting the other, and viceversa. They can be parasites with respect to reproductive success but commen­sals or even mutualists with respect to a person’s other interests. Consider aCatholic priest who takes a vow of celibacy. Reading certain books or masteringcertain cultural skills that help him keep his vow would not enhance his repro­ductive success, but it might further his other interests.

What complicates matters is that some of people’s existing cultural softwarehelps to shape and constitute their interests, and this helps determine what isharmful or helpful. For example, memes that lead a person to watch a lot oftelevision may be mutualist for a person who is a television critic but com­mensal or even parasitic for a person who is a law student.[53]In addition, it isoften difficult to separate the interests of memes from the interests of thepersons whom they constitute. Consider the question of whether being a tele­vision critic is really in my interest. Important features of our personality andimportant choices in our lives may be the result of the cultural software wepossess; they may be inextricably linked to our personal identities and our senseof ourselves.

It is likely that the earliest human memes were predominantly mutualiststhat enhanced our reproductive success.[54]They helped human beings (and hu­man genes) do things that helped them survive and reproduce. Primitive sys­tems of communication and cooperation may have been the earliest examples of widely transmitted cultural software among humans. They provided the basicskills necessary for social learning and the spread of culture; and they them­selves spread because these skills improved human beings’ chances at survival.[55]The earliest memes probably built on innate skills. Cooperation skills built onwhatever instincts for social coordination human beings already had; naturallanguages built on innate linguistic skills.

But once the first hardy memes took root and spread widely, they preparedthe way for other memes that could not previously have infected their humanhosts. They created an environment in which new memes could flourish thatdid not necessarily assist human reproductive success, or that even underminedit. In this way, memes, which originally gained a foothold in human minds asa way of increasing genetic fitness, took on a life of their own. They creatednew structures for processing information, and thus new susceptibilities forinfection by ever more exotic forms of memes, including many commensalsand parasites. The new cultural environment in turn created new human in­terests and hence the possibility of ever new forms of mutualists, commensals, and parasites. As a result, the cultural world we inhabit today contains all three kinds of cultural symbionts.

To be sure, memes are at a severe competitive disadvantage if they routinelythreaten the survival of their human carriers; an example would be a belief inthe necessity of suicide.[56]At first one might think this to be true of beliefs that encourage violent confrontations, war, and murder. But as long as a meme can propagate and reproduce fast enough in enough human beings, the destructionof large numbers of belief carriers is not necessarily fatal to the meme’s con­tinued survival. Indeed, to the extent that violence reinforces the violent oraggressive beliefs of the surviving human carriers-for example, by confirmingthat hatred of the other is justified and that only strength can ensure safety­this may even have a salutary effect on the propagation and survival of violent or aggressive belief.[57](Compare the rabies virus, which eventually kills the dogbut in the process spreads itself by promoting aggressive behavior.) A similar point applies to the many different cultural skills involved in warfare and de­struction. As long as the skills involved in killing people do not completely exterminate the earth’s population, these skills will find a welcome home inhuman minds and propagate accordingly.

The complicated relationship between the interests of memes and theirhuman carriers has a partial analogy in biological evolution. Darwinian pro­cesses of natural selection can simultaneously occur at several different levels,with the result that they “leak” into each other or have feedback effects oneach other.[58]That is because an entity that is the object of natural selectionwithin a particular environment can also itself be the environment in whichanother Darwinian process occurs. Human beings are objects of natural selec­tion in their environment, but human bodies and human cells are also envi­ronments where lower-level processes of natural selection can occur. Humancells use DNA for replication, but only a small percentage of human DNAactually is involved in providing the necessary codes for constructing proteins.Much of the rest contains sequences randomly dispersed and repeated over andover again, with no apparentfunction.[59]Although some of this DNA mayindeed have beneficial effects, the best explanation for it lies elsewhere. Simply put, this DNA has found a way to make copies of itself within the “environ­ment” of human cells and does so because of a familiar Darwinian logic: DNA that does not reproduce itself in this way, or does so less efficiently, will, over time, be increasingly less represented in human cells.

Nevertheless, the human body can be adversely affected by the proliferationof these unnecessary copies in human chromosomes. If this repetitious DNAwere to completely take over human cells, it would kill them or so exhausttheir energies that it would cause a significant disadvantage for the survival ofits environment, the human body, and thus pose a significant threat to its ownsurvival.[60]On the other hand, if the replication of redundant DNA does notsignificantly damage or otherwise reduce the survival and reproduction of hu­man bodies, then it will not be weeded out by the higher-level Darwinianprocess. Hence, redundant DNA acts as a sort of “intelligent parasite,” mul­tiplying as much as it can, but not so much that it kills the goose that lays thegolden eggs.[61]Thus, there is a sort of feedback effect between the two different levels, an interaction between two Darwinian processes. The lower-level unitsof selection have an interest, albeit an attenuated and imprecise one, in thesurvival and propagation of the higher-level units of selection that constitute their environment.

No doubt a similar feedback between the survival interests of human beingsand memes is also at work in cultural evolution. As long as memetic evolutionhas no immediate disadvantage for human survival, it is free to develop in manydifferent directions, with unpredictable long-term effects for the human carriersof culture. Moreover, for those who are suitably paranoid, there may even comea time when computers and robots do the jobs of propagating information andreproducing themselves so efficiently that human survival becomes largely irrelevant to memes. At that point we may well have designed ourselves intooblivion.

The inevitable spread of parasitic and commensal memes undermines the strongest sociobiological claims that human culture is the faithful servant ofhuman reproductive success. A complicated process of feedback between genesand memes is more plausible. Lumsden and Wilson argue that genes are largelyin control of memes; they claim that “genetic natural selection operates in sucha way as to keep culture on a leash.”[62]This is an unintentionally apt metaphor.As most dog owners quickly learn, it is sometimes difficult to tell who is drag­ging whom around.[63]

If parasitic memes arise, why doesn’t the human body evolve to avoid them?In the biological world, organisms do evolve to resist parasites. Hosts that areeasily infected by parasites may tend to produce fewer offspring, so over time natural selection favors hosts that develop ways of preventing infection. Butnatural selection also creates pressures on parasites to increase their abilities toinfect and replicate.[64]The result is a sort of arms race in which parasite andhost attempt to develop newer and more effective measures to produce andprevent infection, respectively.[65]If parasites can evolve faster than their hosts,natural selection enables them to adapt to their hosts’ defenses more quicklythan the hosts can adapt to create new ones. Parasites that go through manygenerations in a relatively short period of time (like bacteria or viruses) aremore likely to win an arms race because natural selection works faster onthem.[66]

Of course, hosts have other ways of dealing with parasites. They can createincentives for parasites to develop into commensals or mutualists, for example,by developing a more hospitable environment for variants less harmful to thehost. They can even modify their own characteristics so that their guests areless harmful to them. And, as we have seen, there are also evolutionary pres­sures on parasites to rein in their harmful effects. If a parasite is too virulentit will destroy its host too quickly and lessen its chances for future transmissionto new hosts.[67]So pressures to increase infection rates compete with pressures to become less harmful to the host-at least before the parasite has transmittedits genes.

Memes are constantly mutating and recombining; they evolve much faster than human genes can. Thus they would almost always win an arms race withthe human body. But there is an important difference between the biologicaland cultural worlds. Memes are usually transmitted to people already consti­tuted by many existing memes and meme complexes. Indeed, most memeticinfection is possible only because human minds are already infested with othermemes-for example, linguistic skills. So parasitic memes do not simply invadean unaided human host; they compete against an army of cultural software thatcan adapt more quickly than human genes.

Thus human beings develop memetic filters to ward off potential culturalparasites. Education, for example, can enable us to discriminate between usefuland harmful ideas and to ward off bad influences; we can use our powers ofreason to overcome our prejudices and persuade others to do likewise. Ourcultural software is a bit like an immune system, which attempts to weed outvirulent infections. Sometimes the immune system does not recognize the in­vader as a danger, sometimes it is overtaxed by the infection, and sometimesit overreacts to a harmless invader, as in the case of allergies.[68]Like immune systems, our cultural software will never have perfect information-it will al­ways engage in rules of thumb, encouraging infection by those memes mostlikely to be beneficial and blocking or neutralizing those that might be harmful.

All of these defense mechanisms have an interesting effect: they fundamen­tally change the nature of the organism being defended. People ward off somememes by incorporating others. In the process, they become cultural beings,interested no longer simply in the reproduction of their genetic informationbut also in the promulgation and protection of their beliefs, values, and skills.Human beings resist culture only by allowing themselves to be conqueredby it.

If our memes do affect our behavior, one of the most important ways is by promoting their own propagation. Space in the minds of human beings is lim­ited. So is the time needed to read the books, listen to the music, and learnthe motor skills involved in successful cultural transmission. There is not onlyextensive competition among memes for space in the minds of prospectivehosts, but also competition within any existing host for behavior devoted topropagation.[69]Thus, some (but not all) of our behavior can be seen as thedemands for the reproduction of our various memes, just as some (but not all)of our behavior can be seen as responding to demands for the reproduction ofour genes.Many forms of human behavior seem consistent with this hypothesis. Par­ents not only want their children to survive; they want to pass along theirculture and religious beliefs to their children as well. Parents do not want thismerely because they believe that these skills and beliefs will enhance their chil­dren’s future reproductive success; they also want to perpetuate their own re­ligious and cultural beliefs. People can thus be cultural parents as well asbiological parents, and bonds of cultural transmission (as in adoptive or fosterparenting) can often be strong indeed. Biological parents whose children areraised by others may feel a sense of loss for many reasons, but surely one isthe failure to pass along their values and beliefs.

People transmit cultural software not only through the family but alsothrough education. Teachers and mentors can sometimes have quasi-parental interests in the success of their students and proteges, their intellectual off­spring. Academics sometimes fight heatedly about hiring and tenure decisionsbecause they want to ensure that people with similar disciplinary commitmentssucceed them.

Most important, people often seem to have a deep interest in propagationof cultural beliefs to total strangers, as is demonstrated by religious proselyti­zation. If culture were simply a domesticated pet on Lumsden and Wilson’sgenetic leash, we would expect that people would pass their most treasuredmemes only to their relatives, as a sort of “family secret” that would benefitfuture reproductive success.[70]In fact, we see quite the opposite phenomenon.People are often very interested in the propagation of their cultural softwarein perfect strangers, whose minds they view as fertile ground for the spread ofmemes.

This motivation is partly explained by the benefits that come from socialcoordination. I may have interests, for example, in ensuring that everyonespeaks the same language and drives on the same side of the road as I do. Butmuch of our discomfort with cultural differences cannot be explained in thisway. Much proselytization cannot simply be seen as a desire to solve collectiveaction problems. There are real advantages to being in the cultural majority,but they stem from the fact that majorities tend to take care of their owncommon interests, usually to the detriment of cultural minorities.

Altruistic behavior between people who share similar cultural software andoppression or neglect of those with different cultural software would makesense if one goal of human behavior were to propagate memes. Evolutionarybiologists argue that competition between genes sometimes leads to cooperativebehavior between individuals that maximizes the reproductive success of theircommonly held genes.[71]We might expect to see the same thing in the worldof culture. Religious groups, academic disciplines, and political parties mayhelp spread and preserve memes more efficiently than individual action.[72]The flip side of ideological and religious conflicts, after all, is relative agreementand cooperation within each of the warring sides.

Just as individuals have varying degrees of genetic kinship, they also havevarying degrees of memetic kinship.[73]The two forms of kinship are cross­cutting: people can have many of the same memes even if they are completelyunrelated. If the analogy to evolutionary arguments about kin-based altruismholds, then we would predict considerable altruistic behavior between peoplewith lots of similar cultural software-for example, people of the same religionor culture, teachers and students, members of the same fraternity or club. Ofcourse, just as in the case of genetic explanations of altruism, not all altruisticbehavior can or should be explained in this way.

We often see people energetically promulgating their memes in the formsof beliefs, behaviors, artifacts, and customs while struggling with others who resist or disagree. Just as competition between biological kin groups can leadto strife, so can competition between cultural kin groups. The history of hu­manity is littered with religious wars, ideological conflicts, and partisan dis­putes, many of which cross lines of genetic kinship.[74]Within the tiny world ofthe academy, participants jealously guard their turf and promote their owndisciplines and approaches, often with a violence seemingly out of proportionto the importance of the struggle. It is often said that such conflicts are sobitter because so little is at stake. From the standpoint of cultural evolution,however, one might say that a great deal is at stake: control over the repro­duction of cultural software. If memes are programmed to survive and repro­duce, such struggles are serious business, at least for them.Kulturkampfs–orcultural struggles–can be seen quite literally as competition between differentmeme complexes struggling for mastery and survival, using their human car­riers as the means of carrying out this struggle. We can even give a memetic spin to the Gramscian idea of hegemony. Cultural hegemony, we might say,is control over the means of memetic reproduction.

Memes in Conventions and Institutions

Memes are the building blocks of institutions and conventions. As ongoingpractices of understanding and behavior, institutions and conventions producenew memes. But more important, they also reproduce the memes necessary to make them ongoing practices of understanding and behavior. Institutions andconventions involve meme-making memes-they coordinate memes to repro­duce themselves.

Take, for example, the institution of a club or a lodge.[75]The institution of a lodge usually involves memes for common practices or rituals that distinguish its members, memes for behaving altruistically toward other members, andmemes for gaining new members to continue the practices and rituals of thelodge. If these memes are properly adjusted to each other and to their envi­ronment, the entire complex of memes will be self-perpetuating. People willcontinue to join the lodge over many years, and its rituals will be perpetuatedin its members.

A second example is an annual lecture.[76]An annual lecture series involvesa series of coordinated skills that produce new memes (the lecture) as well asperpetuating the skills necessary to perpetuate the institution. Put another way,one has to know how to put on an annual lecture series, and this coordinatedbody of cultural know-how by various people constitutes the institution. Theselection committee chooses a speaker every year, the treasurer raises funds,the publicity committee issues invitations to the guests, the guests show up andsit in the audience, the chair introduces the speaker, and the speaker preparesa set of remarks and gives the lecture. Through the coordination of thesevarious skills, new memes are distributed (those in the lecture and in the bro­chures, for example), but more important, expectations are created for the per­petuation of the lecture series in the following year.

In both of these examples, the meme-making institutions and conventionsdepend on a delicate ecological balance that requires coordination between cultural skills and adaptation to the social environment. If parts of the coor­dinated understandings and actions fail to occur, or if they misfire, the insti­tution can come grinding to a halt; it will fail to produce new memes, inparticular the memes that ensure its reproduction. The lodge may be too picky in its membership requirements, for example, or the treasurer may fail to raise sufficient funds for next year’s lecture. If the environment in which the memesperpetuate changes too much, the institution may find itself unable to repro­duce. Thus a lecture series may fail to gain an audience because of other formsof entertainment, such as television or movies. Conversely, over time, thememes produced by the institution may change. A lodge that began as a socialclub may turn into a charitable organization, a lecture series that began as apopular exposition of recent scientific discoveries may become a more seriousacademic event. Many ancient institutions are able to change their rituals, prac­tices, and beliefs in significant ways and yet retain their self-perpetuating char­acter. Such a task is no small feat, for if the complex of coordinated memeschanges too much or too quickly, it may disturb the equilibrium of cooperationthat assures its continued reproduction. Yet significant transformations do oc­cur, especially over long periods of time. The older versions of the institutionare linked to the present one less by clear resemblance than by a line of me­metic descent.

Conventions and institutions can change over time, but they also resistchange. An important part of cultural conventions and institutions involves expectations about how other people will behave.[77]These expectations not onlyhelp coordinate behavior, they also stabilize and police it. Some degree of creativity and variance is always possible within conventions and institutions, but too great a variance defeats expectations, threatens stability, and endangerscultural reproduction. Hence great change produces resistance. Of course,strong resistance to interferences with successful reproduction is precisely whatwe would expect from self-reproducing entities that emerge from natural se­lection.

Some rational-choice theorists have tried to explain social conventions andinstitutions as coordinated behaviors of rational actors that are able to sur­mount collective-action problems.[78]An example of such a problem is a pris­oner’s dilemma, in which fear of loss from defection by others tempts partiesto defect from coordinated action that might benefit them all. Rational-choicetheorists have tried to show how such coordinated behaviors might arise spon­taneously. The theory of cultural software approaches this problem from aslightly different perspective. Instead of focusing on how rational behavior of human beings might overcome collective-action problems, it focuses on thecollective-action problem faced by memes themselves. We can make an analogyonce again to genes that cooperate with each other to create multi-celled or­ganisms, thereby enhancing their joint survival chances. Conventions and in­stitutions are coordinated complexes of meme-making memes. They cooperatewith each other because this cooperation enhances their joint reproductive suc­cess. By assisting in each other’s reproduction, each meme helps the other gainprecious space in human minds and bodily behaviors.

Conventions and institutions reproduce expectations in people about howothers will behave. These expectations are essential parts of self-reproduction.They are important because they let conventions and institutions “turn thetables” on the problem of collective action. Once cultural expectations are inplace and continually reproduced in human minds, it takes collective effort for variant memes to overcome the settled body of cultural expectations.

Why switch our focus from the rational actor to the unit of cultural trans­mission? I noted earlier that memes can be mutualist, commensal, or parasiticwith respect to their human hosts. Because commensal and even parasiticmemes are an almost inevitable development in cultural evolution, we cannot assume that all conventions and institutions are merely solutions to coordina­tion problems that benefit human hosts, either in terms of their reproductivesuccess or their interests as rational actors. Some conventions and institutions may be commensals, and some may actually be quite harmful.

The history of human culture is the history of human susceptibility tovarious kinds of memes. As people are infected, their memes prepare the wayfor new memes, that, in the process, alter and even increase human susceptibility to memes. Consider, for example, the types of memetic infections made possible by learning a human language. These new susceptibilities are passedalong from generation to generation in the form of human culture. At somepoint in human history, human beings became susceptible to a variety of con­ventions and institutions. They became fertile ground for any number of self-­reproducing complexes of memes. This development may originally have beena good one from the standpoint of human reproductive success. But it madehuman beings susceptible to infection from many different kinds of conventionsthat did not necessarily have the best interests of humanity at heart. Of course,internalized memes do not merely weaken human immunity to new invasionsof memes. They also create a new “immune system” that can ward off someharmful memes. However, this cultural immune system cannot perfectly dis­tinguish between memes that are useful in the long run and those that are not.

Social conventions and institutions are possible because our brains devel­oped so that they were fertile soil for certain types of self-perpetuating skills.But once this fertile ground was created, it became suitable for many different kinds of conventions that might be created in the future, just as fertile soil canadmit weeds as well as useful plants. So we cannot assume that all conventionsare beneficial to the members who engage in them. Some conventions (forexample, slavery) are indeed “solutions” to social coordination problems, butthey are not necessarily beneficial solutions. Other conventions, like the mean­ings of certain fashion designs, are commensal, in that they have very littlebenefit.

Shifting our attention from the interests of rational actors to the “interests”of conventions and institutions themselves-as collections of self-reproducingmemes-puts a very different spin on the growth and development of humanculture. It allows us to understand evolutionary developments without havingto explain them in functionalist terms or in terms of rational benefit to hu­manity. We need no longer conjure up “just-so” stories to explain all of thevarious features of human culture. Instead, we can understand human cultureas a compromise and conflict between the interests of persons, their genes, andtheir memes. We can make better sense of the idea of conventions or institu­tions that literally take on a life of their own, regardless of their current orlong-term benefit to humanity.

This evolutionary approach to conventions has a further advantage. Daw­kins’s original formulation of memes was an extension of his theory of “selfishgenes,” which argued that genes used organisms to maximize their own repro­ductive success. Naturalists like Stephen Jay Gould and Richard Lewontin have countered that too exclusive a focus on the gene fails to reckon with the con­straining force of the architecture of organisms.[79]Gould and Lewontin’s attackon the “adaptationist program” reminds us that “organisms are not so muchparagons of design as compromises of design.”[80]Natural selection cannot al­ways perfectly hone organisms to maximal reproductive success in their eco­logical niches. Organisms may lack the necessary genetic variation for naturalselection to do its work. Previous design choices may limit future innovations,allowing only bricolage rather than bottom-up design.

A similar point applies to the complexes of memes we find in conventionsand institutions: they too are compromises of design. Only some changes arepossible if conventions and institutions are to maintain their self-reproducingcharacter. And, like species, they also face “architectural” constraints. They canonly change in certain ways, given their previous history and the cultural meansat hand. Hence, conventions and institutions produced through cultural evo­lution are highly unlikely to perfectly optimize any external standards of designin their current environment, whether that standard be social functionality, moral efficacy, or economic efficiency.[81]Indeed, the imperfections and thejerry-built character of conventions and institutions are the best evidence of their historical development. This realization connects the theory of memeticevolution with my discussion of cultural bricolage in Chapter 2.

We cannot always infer the current utility of a feature of a convention or institution from its current existence. And we cannot infer from a feature’scurrent utility the reasons for its origin. Rather, we are likely to see, in Gould’sphrase, “panda’s thumbs” in both conventions and institutions. Cultural de­velopments of social conventions and institutions are likely to be exaptations,in which memes adapt old features to new uses in a changed environment.Features of existing conventions and institutions may often have arisen for onereason, but now serve very different functions and purposes.

The argument I have just presented synthesizes Dawkins’s concept ofmemes with Gould’s theory of architectural constraint. The concept of memeswas originally coined by Dawkins, whose views about adaptation have been criticized by Gould. But once we take into account the role of meme complexesin cultural evolution, and the need for these complexes to reproduce togetherin a given ecology, we see that Gould’s point about evolutionary bricolageapplies with equal force to models of cultural evolution. And this requires usto modify Dawkins’s original conception of memetic evolution.

Indeed, there is something entirely fitting in bringing these two seeminglydisparate strands of evolutionary theory together. The original inspiration forGould and Lewontin’s theory of evolutionary bricolage was an example drawnfrom the world of culture-the spandrels in the Basilica of San Marco. Span­drels are triangular spaces created when one places a cathedral dome on top offour rounded archways set at right angles to each other. Artists made use ofthese spaces to place elaborate mosaics and other decorations. Gould and Le­wontin pointed out that it would be fallacious to assume that the basilica wasdesigned to produce the decorative spandrels; rather the custom of decorating the spandrels is simply an ingenious use of spaces that necessarily resulted from previous limitations on the design of cathedrals.[82]In the same way, if we wishto study the development of cultural software, we must not assume that all features of human thought and practice are currently or perfectly adaptive tomemetic survival. Rather, we must patiently investigate the ways in which layersof memetic innovation occur given the existing constraints of human thoughtand human cultural conventions.

[1]Richard Dawkins,The Selfish Gene(Oxford: Oxford University Press, new ed.,1989), 192.

[2]See Daniel C. Dennett,Consciousness Explained(Boston: Little, Brown, 1991),200; Dawkins,The Selfish Gene,322.

[3]Graham Cairns-Smith,Genetic Takeover and the Mineral Origins of Life(Cam­bridge: Cambridge University Press, 1982); Graham Cairns-Smith,Seven Clues to theOriginof Life: A Scientific Detective Story(Cambridge: Cambridge University Press, 1985).

[4]Dawkins,The Selfish Gene,192.

[5]Robert Boyd and Peter J. Richerson, “The Evolution of Norms: An Anthro­pological View,”JournalofInstitutional and Theoretical Economics150, no. 1 (1994): 72­87, at 74; Robert Boyd and Peter J. Richerson,Cultureand the Evolutionary Process(Chi­cago: University of Chicago Press, 1985).

[6]See,e.g.,Daniel C. Dennett,Darwin’s Dangerous Idea: Evolution and the MeaningsofLife(New York: Simon and Schuster, 1995), 344; Henry C. Plotkin,Darwin Machinesand the NatureofKnowledge(Cambridge: Harvard University Press, 1994), 215; RichardBrodie,Virusofthe Mind: The New Scienceofthe Meme(Seattle: Integral, 1996); AaronLynch,Thought Contagion: How Belief Spreads Through Society(New York: Basic, 1996).By contrast, I argue that the most basic forms of memes and meme complexes are skills.

[7]Thus the different uses of cultural tools offered in Chapter 2 can all be redes­cribed as different aspects of cultural know-how. Knowing how to get about in the world,how to deal with others, and how to articulate one’s values all can be and are transmittedin the form of memes.

[8]In terms of our computer metaphor, the primacy of knowing how over knowingthat tends to blur the distinction between information (data) and code (instructions). Yetthis distinction is already blurred when we define memes as units of cultural transmission.If memes are to be transmitted to others, and thus become cultural, they must have some observable effects on human behavior-at the very least enough so that they arein fact transmitted. See John A. Ball, “Memes as Replicators,”Ethology and Sociobiology5 (1984): 145-61, at 154.

[9]Dan Sperber,Explaining Culture: A Naturalistic Approach(Oxford: Blackwell 1996), 24.

[10]Dennett,Darwin’s Dangerous Idea,353.

[12]Dan Sperber and Deirdre Wilson,Relevance: Communication and Cognition (Ox­ford: Blackwell, 1986).

[14]Dennett,Consciousness Explained,201; see Dawkins,The Selfish Gene,195.

[15]Dennett,Darwin’s Dangerous Idea,344.

[16]In the key of D, the notes aref#’-e’-d’-b-a-f#-a-d’-b-a.

[19]Ernst Mayr,The Growth of Biological Thought(Cambridge: Harvard University Press, 1982), 46-47.

[20]Dan Sperber, “Anthropology and Psychology: Towards an Epidemiology ofRepresentations,”Mann.s. 20 (1985): 73-89, at 74.

[21]Sanford Levinson and J. M. Balkin, “Law, Music, and Other Performing Arts,”Universityof PennsylvaniaLaw Review139 (1991): 1597-1658, at 1623.

[22]Juan Delius, “The Nature of Culture,” inThe Timbergen Legacy,M.S. Dawkins,T. R. Halliday, and R. Dawkins, eds. (London: Chapman and Hall, 1991), 71-99, at 81.As Delius points out, “Culture as a persistent phenomenon is heavily dependent onlong-term memories.”

[23]Dennett,Darwin’s Dangerous Idea,348-49.

[24]See Dawkins,The Selfish Gene,199.

[25]This feature of cultural transmission underlies the deconstructive theory of thesign. The public nature of communication requires that signs be able to signify repeat­edly to new users and in new contexts regardless of the intentions that originally createdthem. This ability of signs to be detached from the author’s private intentions, and tomean something other than what the author meant, makes iterability, and hence inter­subjective meaning, possible. See J. M. Balkin, “Deconstructive Practice and Legal The­ory,”Yale Law Journal96 (1987): 743-86, at 779-81. As a sign is repeatedly understood,it takes on a life of its own in a relation of partial similarity and partial difference fromthe person who meant it. Repetition of a sign in a new context is simultaneously a relation of identity and difference; the repeated sign is syntactically identical, yet se­mantically different. Hence the deconstructive aphorism that “iterability alters.” JacquesDerrida, “Limited Inc abc…,”Glyph2(1977): 162-254, at 200.

[26]Dennett,Darwin’s Dangerous Idea,353-56.

[27]See Jon Elster,Sour Grapes: Studies in the Subversion of Rationality(Cambridge:Cambridge University Press, 1983), 152-53.

[28]See the discussion of cognitive dissonance theory in Chapter 8.

[29]Charles Darwin,On the Origin of Species by Means of Natural Selection,inThePortable Darwin,Duncan M. Porter and Peter W. Graham, eds. (New York: Penguin,1993), 185; Niles Eldredge, Reinventing Darwin: The Great Debate at the HighTable of Evolutionary Theory(New York: Wiley, 1995), 50.

[30]James Burke,Connections(Boston: Little, Brown, 1978), 108-13. This book,based on the television series of the 1970s, contains many wonderful examples of tech­nological borrowing.

[31]See Stephen Jay Gould, “The Panda’s Thumb of Technology,” inBully for Brontosaurus(New York: Norton, 1991), 59-75, at 65. The ability of memes to combinein human minds means that cladistics-the study of lineages-is extremely difficult inthe case of memes. Yet it is an important element in the study of biological evolution.Eldredge,Reinventing Darwin, 53-55.One might think of intellectual history as a sortof cladistics of memes. Intellectual historians often try to study ideas as they changethrough history, but the theory of memes suggests why this enterprise presents so manycomplications.

[33]See Dennett,Consciousness Explained, 204: Donald Campbell, “Comments on the Sociobiology of Ethics and Moralizing,”Behavioral Science24 (1979): 37-45.

[34]Dennett,Darwin’s Dangerous Idea,348. As Dennett points out, “Plato’s ideassurvive not because of the survival of individual papyrus manuscripts, but because theywere continuously copied.”

[35]See Donald R. Griffin,Animal Minds(Chicago: University of Chicago Press,1992); John Tyler Bonner,The EvolutionofCulture in Animals(Princeton: Princeton University Press, 1980); Merlin Donald,Originsofthe Modern Mind: Three Stages in theEvolutionofCulture and Cognition(Cambridge: Harvard University Press, 1991).

[36]Thus birdsongs are a kind of meme that can survive in the environment thatbird’s minds and bodies provide. See Dawkins,The Selfish Gene,189-90.

[37]Dennett,Consciousness Explained,202.

[38]Ibid., 202, 206.

[39]See Dennett,Consciousness Explained,218.

[42]Dennett,Darwin’s Dangerous Idea,350.

[43]Richard Nisbett and Lee Ross,Human Inference: Strategies and ShortcomingsofSocial Judgment(Englewood Cliffs, NJ.: Prentice-Hall, 1980), 169-88.44. See the discussion in Chapter 8.

[44]See the discussion in Chapter 8.

[45]Dennett,Darwin’s Dangerous Idea,351.

[48]Sperber, “Anthropology and Psychology,” 74. Brodie,Virusofthe Mind,andLynch,Thought Contagion,are two recent accounts of memetics that are organizedaround the communicable-disease analogy. Each offers abundant historical and culturalexamples.

[49]Dennett,Darwin’s Dangerous Idea,352.

[50]Sperber, “Anthropology and Psychology,” 74.

[51]Delius, “The Nature of Culture,” 84.

[52]Ibid., 84-85.

[53]Ibid., 86-87.

[55]Charles J. Lumsden and Edward O. Wilson,Genes, Mind, and Culture: The Co­evolutionary Process(Cambridge: Harvard University Press, 1981).

[56]Dennett,Consciousness Explained,203; Richard Dawkins,The Extended Phenotype(San Francisco: Freeman, 1982), 110-11.

[57]Conspiracy theories and beliefs that are linked to prohibitions against exposingone’s self to contrary beliefs are also good examples of self-reinforcing beliefs. See Den­nett,Consciousness Explained,206; Dawkins,The Selfish Gene,198-99.

[58]Stephen Jay Gould,Hen’s Teeth and Horse’s Toes(New York: Norton, 1983),174­75.

[62]Lumsden and Wilson,Genes, Mind, and Culture,13.

[63]The fact that so many members of the Catholic clergy have been able to suppresstheir reproductive urges over so many years is perhaps the best evidence of the powerof memes over genes. Even though Catholic clergy occasionally (and predictably) havegone astray, the degree of celibacy that they have been able to practice over the centuries is certainly remarkable.

[64]An example is the development of strains of bacteria that are resistant to anti­biotics-although this is a response not to human biological evolution but to changesin human technology.

[65]George C. Williams and Randolph M. Neese, “The Dawn of Darwinian Med­icine,Quarterly Review of Biology66, no. 1 (March 1991): 1-22, at 7.

[66]Delius, “The Nature of Culture,” 86, 91.

[70]Ibid., 89-90.

[71]See Alexander Rosenberg, “Altruism: Theoretical Contexts,” inKeywords in Evo­lutionary Biology,Evelyn Fox Keller and Elisabeth A. Lloyd, eds. (Cambridge: Harvard University Press, 1992), 19-28.

[72]Delius, “The Nature of Culture,” 93-94.

[74]Because memetic kinship can differ from genetic kinship, sometimes cultural andbiological altruism will be reinforcing and sometimes they will be at odds. The bondbetween parents and children is no doubt strengthened by the cultural transmission thatusually accompanies parenting. On the other hand, there are many stories of familiessplit asunder by civil wars and religious disputes.

[75]Ball, “Memes as Replicators,” 156.

[76]Sperber, “Anthropology and Psychology,” 86.

[77]For a helpful discussion see Roger C. Schank,The Connoisseur’s Guide to the Mind:How We Think, How We Learn, and What It Means to Be Intelligent(New York: Summit,1991), 35-41.

[78]See,e.g., Ken Binmore,Game Theory and the Social Contract: Playing Fair, vol. 1(Cambridge: MIT Press, 1994); Robert Axelrod,The Evolution of Cooperation(New York:Basic, 1984); Edna Ullmann-Margalit,The Emergence of Norms(Oxford: Clarendon,1977).

[79]Stephen Jay Gould and Richard C. Lewontin, “The Spandrels of San Marcoand the Panglossian Paradigm: A Critique of the Adaptationist Programme,”Proceedingsof the Royal Society, London(1979) B.205: 581-98.

[80]Eldredge,Reinventing Darwin, p.46.

[81] For examples of this point in the evolution of accident law, see J. M. Balkin:”Too Good to Be True: The Positive Economic Theory of Law,”Columbia Law Review87 (1987): 1447-89.