DRAFT. for Chapel Hill, October 1998

Daniel C. Dennett

Memes: Myths, Misunderstandings and Misgivings

Richard Dawkins introduced the concept of memes in his 1976 book, The Selfish Gene, and the reception for many years was chilly. Then, recently, thanks in part to some energetic campaigning by me on behalf of the meme meme (mainly in Consciousness Explained and Darwin's Dangerous Idea), the friends of memes began to come out of the woodwork, and a number of books and articles about memes (of varying quality) have begun attracting a second look. Currently the internet blooms with dozens of websites proclaiming the birth of the new science of memetics. Most of this is simply awful, but that should not surprise us. As Sturgeon's Law reminds us, 95% of everything is crap. The hard part--especially during these early days of proto-memetics--is to identify the 5% that is actually good. Sturgeon's Law also suggests, of course, that 95% of the criticism of memes and memetics is also crap, so we needn't waste our time rebutting every silly, anxiety-driven objection. My talk will be an attempt to focus on some of the more attention-worthy issues.

1. Perspectives on Cultural Evolution(1)

When one says that cultures evolve, this can be taken as a truism, or as asserting one or another controversial, speculative, unconfirmed theory. Consider a cultural inventory at time t: it includes all the languages, practices, ceremonies, edifices, methods, tools, myths, music, art, and so forth, that compose a culture. Over time, the inventory changes. Some items disappear, some multiply, some merge, some change. (When I say some change, I mean to be neutral at this point about whether this amounts to their being replaced by similar items, or their undergoing a transformation.) A verbatim record of this history would not be science; it would be a data base. That is the truism: cultures evolve over time. Now the question remains: how are we to explain the patterns found in that data base? Are there any good theories or models of cultural evolution?

The traditional model to be found in most accounts by historians and anthropologists treats culture as composed of goods, possessions of the people, who husband them in various ways, wisely or foolishly. They carefully preserve their traditions of fire-lighting, house-building, speaking, counting, justice, etc. They trade cultural items as they trade other goods. And of course some cultural items (wagons, pasta, recipes for chocolate cake, etc.) are definitely goods, and we can plot their trajectories using the tools of economics. The people, on this model, are seen as having an autonomous or independent rationality; deprive a person of his goods, and he stands there, naked but rational and full of informed desires. When he clothes himself and arms himself and equips himself with goods, he increases his powers, complicates his desires, etc.

On this way of thinking, the relative "replicative" power of various cultural goods is measured in the marketplace of cost-benefit calculations performed by the people. If Coca Cola bottles proliferate around the world, it is because more and more people prefer to buy a Coke. Advertising may fool them. But then we look to the advertisers, or those who have hired them, to find the relevant loci of values for our calculations. Cui bono? Who benefits? The purveyors of the goods, and those they hire to help them.

Biologists, too, can often make sense of the evolution (in the neutral sense) of features by treating them as goods: one's food, one's nest, one's burrow, one's territory, one's mate[s], one's time and energy. Cost-benefit analyses shed light on the husbandry engaged in by the members of the different species inhabiting some shared environment.(2) Not every "possession" is considered a good, however; one's accompanying flies and fleas, the dirt and grime that accumulates on one's body, are of no value, or of negative value, for instance. One's symbionts are not normally considered as goods by biologists, except when the benefits derived from them (by whom?) are manifest.

This perspective is not uniformly illuminating, nor is it obligatory. I would like to suggest that both biologists and economists (and other social scientists) can benefit from adopting a different vantage point on some of these phenomena, one which quite properly gives pride of place to the Cui bono question, which can provide alternative answers that are often overlooked. This is Dawkins' meme's-eye point of view, which recognizes--and takes seriously--the possibility that cultural entities may evolve according to selectional regimes that make sense only when the answer to the Cui bono question is that it is the cultural items themselves that benefit from the adaptations they exhibit.(3)

Dawkins' theory of memes, as briefly sketched in a single chapter of The Selfish Gene (1976, but see also Dawkins, 1993), is hardly a theory at all, especially compared to the models of cultural evolution developed by other biologists, such as Cavalli-Sforza and Feldman (1981), Lumsden and Wilson (1981), and Boyd and Richerson (1985). Unlike these others, Dawkins offers no formal development, no mathematical models, no quantitative predictions, no systematic survey of relevant empirical findings. But Dawkins does present an idea that is overlooked by all the others, and it is, I think, a most important idea. It is the key to understanding how we can be not just guardians and transmitters of culture, but cultural entities ourselves--all the way in.

Whenever costs and benefits are the issue we need to ask Cui bono? A benefit by itself is not explanatory; a benefit in a vacuum is indeed a sort of mystery; until it can be shown how the benefit actually redounds to enhance the replicative power of a replicator, it just sits there, alluring, perhaps, but incapable of explaining anything.

We see an ant laboriously climbing up a stalk of grass. Why is it doing that? Why is that adaptive? What good accrues to the ant by doing that? That is the wrong question to ask. No good accrues to the ant; its brain has been invaded by a fluke (Dicrocoelium dendriticum), one of a gang of tiny parasites that need to get themselves into the intestines of a sheep in order to reproduce (Ridley, 1995, p258). (Salmon swim up stream, these parasitic worms drive ants up grass stalks, to improve their chances of being ingested by a passing sheep.) The benefit is not to the reproductive prospects of the ant but the reproductive prospects of the fluke.(4)

Dawkins points out that we can think of cultural items, memes, as parasites, too. Actually, they are more like a simple virus than a worm. Memes are supposed to be analogous to genes, the replicating entities of the cultural media, but they also have vehicles, or phenotypes; they are like not-so-naked genes. They are like viruses (Dawkins, 1993). As with viruses, there is a phenotype/genotype distinction, but just barely. Basically, a virus is just a string of DNA (or RNA) with attitude. And similarly, a meme is an information-packet (the information, not the vehicle) with attitude--with some phenotypic clothing that has differential effects in the world that thereby influence its chances of getting replicated.

And in the domain of memes, the ultimate beneficiary, the beneficiary in terms of which the final cost-benefit calculations must apply is: the meme itself, not its carriers. This is not to be read as itself a bold empirical claim, ruling out (for instance) the role of individual human agents in devising, appreciating and securing the spread and prolongation of cultural items. It is rather a proposal that we adopt a perspective or point of view, from which a wide variety of different empirical claims can be compared, and the evidence for them considered in a neutral setting, a setting that does not prejudge these hot-button questions.

In the analogy with the fluke, we are invited to consider a meme as like a parasite which commandeers an organism for its own replicative benefit, but we should remember that symbionts can be classified into three fundamental categories:

parasites, whose presence lowers the fitness of their host;

commensals, whose presence is neutral (though, as the etymology reminds us, they "share the same table"); and

mutualists, whose presence enhances the fitness of both host and guest.

Since these varieties are arrayed along a continuum, the boundaries between them need not be too finely drawn; just where benefit drops to zero or turns to harm is not something to be directly measured by any practical test, though we can explore the consequences of these turning points in models.

The main point to note is that we should expect memes to come in all three varieties, too. This means, for instance, that it is a mistake to assume that the "cultural selection" of a cultural trait is always "for cause"--always because of some perceived (or even misperceived) benefit it provides to the host. We can always ask if the hosts, the human agents that are the vectors, perceive some benefit and (for that reason, good or bad) assist in the preservation and replication of the cultural item in question, but we must be prepared to entertain the answer that they do not. In other words, we must consider as a real possibility the hypothesis that the human hosts are, individually or as a group, either oblivious to, or agnostic about, or even positively dead set against, some cultural item, which nevertheless is able to exploit its hosts as vectors.

The most familiar cases of cultural transmission and evolution discussed are innovations that are obviously of some direct or indirect benefit to the Darwinian--that is, genetic--fitness of the host. A better fishhook catches more fish, feeds more bellies, makes for more surviving grandchildren, etc. The only difference between stronger arms and a better fishhook in the (imagined) calculation of impact on fitness is that the stronger arms might be--might be--passed on quite directly through the germ line, while the fishhook definitely must be culturally transmitted. (The stronger arms could be culturally transmitted as well, of course. A tradition of body-building, for instance, could explain why there was very low [genetic] heritability for strong adult arms, and yet a very high rate of strong adult arms in a population.) But however it might be that strong arms or fishhooks are transmitted, they are typically supposed to be a good bargain from the perspective of genetic fitness. The bargain might, however, be myopic--only good in the short run. After all, even agriculture, in the long run, may be a dubious bargain if what you are taking as your summum bonum is Darwinian fitness (see Diamond, 1997, for fascinating reflections on the uncertain benefits of abandoning the hunter-gatherer lifestyle). What alternatives are there?

First, we need to note that in the short run (evolutionarily speaking--that is, from the perspective of a few centuries or even millennia) something might flourish independently of whether it was of actual benefit to genetic fitness, but strongly linked to whether it was of apparent benefit to genetic fitness. Even if you think that Darwinian fitness enhancement is the principle driving engine of cultural evolution, you have to posit some swifter, more immediate mechanism of retention and transmission. It's not hard to find one. Cultural items may exploit machinery that had earned its keep in the past by embodying a fitness-enhancing set of preferences. We are genetically endowed with a quality space in which some things feel good and some things don't, and we tend to live by the rule: if it feels good, keep it. This rough and ready rule can be tricked, of course. The sweet tooth is a standard example. The explosion of cultural items--artifacts, practices, recipes, patterns of agriculture, trade routes--that depend quite directly on the exploitation of the sweet tooth has probably had a considerable net negative effect on human genetic fitness. Notice that explaining the emergence of these cultural items by citing their "apparent" benefit to genetic fitness does not in any way commit us to the (preposterous) claim that people think (mistakenly) that they are enhancing their genetic fitness by acquiring and consuming sugar. The rationale is not theirs, but Mother Nature's. They just go with what they like.

Still, given what they like, they choose rationally, and indeed ingeniously and often with impressive foresight, how to obtain what they like. This is still the traditional model of cultural evolution, with agents husbanding their goods in order to maximize what they prefer--and getting their preferences quite directly from their genetic heritage. A more interesting possibility is acquiring new preferences that are themselves culturally transmitted symbionts of one sort or another. Each will have to bootstrap itself into the memosphere by exploiting some pre-established preference, but this recursive process, which can proceed at breakneck speed relative to the glacial pace of genetic evolution, can transform human agents indefinitely far away from their genetic beginnings. In an oft-quoted passage, E. O. Wilson claimed otherwise:

The genes hold culture on a leash. The leash is very long, but inevitably values will be constrained in accordance with their effects on the human gene pool. (Wilson, 1978, p167)

This leash, I am claiming, is indefinitely long, in the sense that the constraints Wilson speaks of can be so co-opted, exploited, and obtunded in a recursive cascade of cultural products and meta-products that it is not clear that there are any points in imaginable cultural design space that could not, in principle, be occupied by some product that could ultimately be traced back, via Wilson's leash of historical processes, to the genes. Many of these imaginable points would no doubt be genetic culs-de-sac (H. sapiens would sooner or later go extinct as a result of occupying those points), but this is no barrier to their evolving in the swift time of cultural history.(5)

Not only can we acquire tastes; we can acquire meta-tastes. That is, we can discover in the culture, and thereupon adopt, a taste for "cultivating" further acquired tastes, and so forth. At each stage we can anticipate finding parasites, commensals and mutualists--but we can classify these only by asking the Cui bono? question against a new background and making one local determination or another. One person's scholarly connoisseurship is another person's addiction to trash. Meta-memes for "traveling" or "being a collector" or "having a hobby" or "educating oneself" can themselves be viewed as either exploiters or enhancers of the pre-established personal (no longer genetic) preferences. It is interesting that in common parlance we often call our preferences "weaknesses,"--as in "I have a weakness for strong cheese (or puns or redheads)"--deftly implying a standard to which in the same breath we deny any personal allegiance.

And this, then, is the main point I wanted to emphasize in Dawkins' vision. The memes that proliferate will be the memes that replicate by hook or by crook. Think of them as entering the brains of culture members, making phenotypic alterations thereupon, and then submitting themselves to the great selection tournament--not the Darwinian genetic fitness tournament (life is too short for that) but the Dawkinsian meme-fitness tournament. It is their fitness as memes that is on the line, not their host's genetic fitness, and the environments that embody the selective pressures that determine their fitness are composed in large measure of other memes.

Why do their hosts put up with this? Why should the overhead costs of establishing a whole new system of differential reproduction be borne by members of H. sapiens? Note that the question to be asked and answered here is parallel to the question we ask about any symbiont-host relationship: why do the hosts put up with it? And the short answer is that it is too costly to eradicate, but this just means that the benefits accruing to the machinery that is being exploited by the parasites are so great that keeping the machinery and tolerating the parasites (to the extent that they are tolerated) has so far been the best deal available. And whether or not in the long run (millions of years) this infestation will be viewed as mutualism or commensalism or parasitism, in the short run (the last few millennia) the results have been spectacular: the creation of a new biological type of entity: a person.

I like to compare this development to the arrival of the eukaryotes more than a billion years ago. Relatively simple prokaryotes got invaded by some of their neighbors, and the resulting endosymbiotic teams were more fit, and prospered, enabling a biological revolution. The eukaryotes, living alongside their prokaryotic cousins, but enormously more complex, versatile and competent, opened up the design space of multi-cellular organisms. Similarly, the emergence of culture-infected hominids has opened up yet another region of hitherto unoccupied and untraversable design space. We live alongside our animal cousins, but we are enormously more complex, versatile and competent. And by joining forces with our memes, we create new candidates for the locus of benefit, new answers to Cui bono?

2. Two all too standard Objections

One often hears it said that the ways in which cultural entities evolve are profoundly un-Darwinian. Two claims in particular, are often presented as if they carried the day: cultural evolution, unlike Darwinian evolution, is "Lamarckian," and cultural evolution, unlike Darwinian evolution, is replete with "horizontal transmission"--that is to say, design elements can hop freely from lineage to lineage, not bound by the requirements of heredity. Once reptiles and mammals have gone their separate ways, reptile innovations cannot jump to mammals, but only to descendant reptiles, but this restriction does not exist in cultural evolution. I have sometimes wondered why we don't hear more about a third disanalogy: cultural ideas don't reproduce sexually--mama and papa ideas getting it on to make little baby ideas of both genders. Probably we don't hear it because it would wear its disingenousness on its sleeve--a lazy (or desperate) stab at something that would excuse one from having to think further about the prospects of a Darwinian account of culture. Sexual reproduction is not, after all, an obligatory element of Darwinian evolution; surely 99% of all the Darwinian evolution that has ever occurred on this planet was among asexually reproducing replicators, and however large sexuality looms now, it is itself an evolved feature, not a precondition for Darwinian evolution. So the absence of sexual reproduction in the memosphere is no challenge to neo-Darwinian explanation. But exactly the same point can be made about the purported disanalogies of Lamarckianism and horizontal transmission or anastomosis (lineage-joining).

Let's consider Lamarckianism first. Neo-Darwinian orthodoxy, since Weissman, declares that characteristics acquired through use cannot be transmitted genetically to one's progeny. Darwin himself, notoriously, was quite happy to countenance this feature of Lamarckianism, but he has long been deemed in error. Weissman's distinction between germ line--roughly, eggs and sperm-- and somatic line cells--all the rest--has proven itself over and over, and the doctrine that there are no avenues by which somatic line innovations could enter the germ line is indeed a textbook verity, although various exotic possibilities have been seriously discussed in the literature, and arguably exist in some restricted quarters. But notice that this, the orthodox, way of identifying Lamarckian phenomena (as things that don't happen) applies crisply only to multi-cellular organisms. What counts as a Lamarckian phenomenon in the world of bacteria, archaea, or in the world of viruses? In the case of a virus, which I have described as just a string of DNA with attitude, the line between soma and germ line is non-existent. Something that changes the structure of an individual virus string can be called a genotypic change--a mutation--if it is passed on in replication, and otherwise a mere phenotypic change. It is not that such a line can't be drawn, but it becomes a line that prohibits nothing. The claim that Lamarckianism has been vindicated in the world of viral evolution would thus be Pickwickian. And since memes are no more multicellular than they are sexual, the fact that there is no clear way---no "principled" way, as they used to say at MIT--of distinguishing mutations from phenotypic acquisitions hardly shows that they are disqualified from a neo-Darwinian treatment.(6) Most--much more than 99%-- of the life forms on this planet have evolved under just such a regime, and neo-Darwinism certainly covers their evolution handily.

And the same verdict applies to anastomosis, although this is a recent and ill-appreciated discovery: there is lots of horizontal transmission in protist and bacterial evolution--a fact that plays hob with attempts to define separate bacterial lineages in a "principled" way--and once again, the bulk of the evolution on the planet has been amongst just such tiny bits. Once we shift our focus away from our own multicellular, sexually reproducing lineages to the more numerous lineages on the planet, these standard objections lose much if not all their force. Memes are indeed not very much like elephant genomes, but so what?

3. But what about human reason--and creativity?(7)

A confusion that misdirects the imagination of theorists in another direction derives, I suspect, from a subtle misreading of Darwin's original use of artificial selection (deliberate animal breeding) and "unconscious" selection (the unwitting promotion of favored offspring of domesticated animals) as bridges to his concept of natural selection. While it is true that Darwin wished to contrast the utter lack of foresight or intention in natural selection with the deliberate goal-seeking of the artificial selectors, in order to show how the natural process could in principle proceed without any mentality at all, he did not thereby establish (as many seem to have supposed) that deliberate, goal-directed, intentional selection is not a subvariety of natural selection! The short legs of dachshunds, and the huge udders of Holsteins are just as much products of natural selection as the wings of the eagle; they just evolved in an environment that included a particularly well-focussed selective pressure consisting of human agents. These phenotypes fall under the same laws of transmission genetics, the same replicator dynamics, as any others--as special and extreme cases in which the default "randomness" or noisiness of selective pressure has been greatly reduced.

Applied to cultural evolution, the implication is this: There is no conflict between the claim that artifacts (including abstract artifacts--memes) are the products of natural selection, and the claim that they are (often) the foreseen, designed products of intentional human activity. It appears that some thinkers in the newly emerging school of evolutionary archeology have made this mistake. According to a critique by Boone and Smith (1998), at least some evolutionary archeologists think that the only way to be hardheaded and scientific about the Darwinian evolution of culture is to deny all intention, all rationality, on the part of human culture-makers. They opt for "selection rather than decision-making" [p11]. That is simply a mistake, for the same reason it would be a mistake to say that the fancy plumage of prize pigeons is the result of decision-making rather than selection. But Boone and Smith fall in the same trap, in their discussion of the interesting phenomenon of the spread of snowmobiles among the Cree in northern Canada. They are surely right that the adoption of snowmobiles by the Cree cannot be accounted for in terms of the differential biological replication of the snowmobile users, but they misread the more interesting meme's-eye view perspective. They say:

The alterative that 'snowmobile memes' were transmitted more effectively than 'snowshoe memes' to non-descendant Cree (as well as offspring), while plausible, is not natural selection [emphasis added]; more significantly, it requires precisely the kind of adaptive decision-making that EA [evolutionary archeology] is dedicated to eliminating from archeological explanation. [ms p12]

On the contrary, if you adopt the meme's-eye perspective, in which the snowmobile meme is seen as the replicator, with its own fitness, then cultural evolution can be seen to be due to "adaptive decision-making" while also a variety of natural selection. Consider the fitness of the domesticated horses that spread so quickly among the Native Americans after their introduction, but then more recently, after the advent of the automobile, have dwindled sharply. These fluctuations in genetic fitness have been due to changes in the selective forces arrayed in the various environments in which the horses have existed, of course, and the fact that conscious, foresightful human agents form the key component in those selective environments does nothing to remove the phenomena from the domain of standard genetic evolution by natural selection.

Among those who have overlooked this fact is Steven Pinker, who dismisses models of cultural evolution in a brief passage in How the Mind Works (1997):

Stop being so literal-minded! respond the fans of cultural evolution. Of course cultural evolution is not an exact replica of the Darwinian version. In cultural evolution, the mutations are directed and the acquired characteristics are inherited. Lamarck, while being wrong about biological evolution, turned out to be right about cultural evolution. . .To say that cultural evolution is Lamarckian is to confess that one has no idea how it works. The striking features of cultural products, namely their ingenuity, beauty, and truth (analogous to organisms' complex adaptive design), come from the mental computations that "direct"--that is, invent--the "mutations," and that "acquire"--that is, understand--the "characteristics." (1997, p209)

Pinker has imputed the wrong parallel; it is not Lamarck's model, but Darwin's model of artificial selection (as a special case of natural selection) that accommodates the phenomena he draws to our attention in this passage. And it is ironic that Pinker overlooks this, since the cultural phenomena he himself has highlighted as examples of evolution-designed systems, linguistic phenomena, are almost certainly not the products of foresightful, ingenious, deliberate human invention. Some designed features of human languages are no doubt genetically transmitted, but many others--such as changes in pronunciation, for instance--are surely culturally transmitted, and hence products of cultural, not genetic, evolution.

Some memes are like domesticated animals; they are prized for their benefits, and their replication is closely fostered and relatively well understood by their human owners. Some memes are more like rats; they thrive in the human environment in spite of being positively selected against--ineffectually--by their unwilling hosts. And some are more like bacteria or other viruses, commandeering aspects of human behavior (provoking sneezing, for instance) in their "efforts" to propagate from host to host. There is artificial selection of "good" memes--like the memes of arithmetic and writing, which are carefully taught to each new generation. And there is unconscious selection of memes of all sorts--like the subtle mutations in pronunciation that spread through linguistic groups, presumably with some efficiency advantage, but perhaps just hitchhiking on some quirk of human preference. And there is unconscious selection of memes that are positively a menace, but which prey on flaws in the human decision-making apparatus, as provided for in the genome and enhanced and adjusted by other cultural innovations--such as the abducted-by-aliens meme, which makes perfect sense when its own fitness as a cultural replicator is considered. Only the meme's-eye perspective unites all these possibilities under one view.(8)

Finally, one of the most persistent sources of discomfort about memes is the dread suspicion that an account of human minds in terms of brains being parasitized by memes will undermine the precious traditions of human creativity. On the contrary, I think it is clear that only an account of creativity in terms of memes has much of a chance of giving us any way to identify with the products of our own minds. We human beings extrude other products, on a daily basis, but after infancy, at any rate, we don't tend to view our feces with the pride of an author or artist. These are mere biological byproducts, and although they have their own modest individuality and idosyncracy, it is not anything we cherish. How could we justify viewing the secretions of our poor infected brains with any more pride? Because we identify with some subset of the memes we harbor. Why? Because among the memes we harbor are those that put a premium on identifying with just such a subset of memes! Lacking that meme-borne attitude, we would be mere loci of interaction, but we have such memes--that is who we are.

4. Conclusion

This spectrum of possibilities, from the unwitting, unconscious hosting of culture-borne viruses (of all "attitudes") to the foresightful design and promulgation of inventions and creations that intelligently and artfully draw upon well-understood cultural resources, must be viewable under a single, unifying perspective. It is only from such a perspective that we can make sense of the trajectories that have taken us--and only us--beyond the horizons of our selfish genes, by creating new environments of selection--persons and their projects--that in turn create utterly unprecedented answers to the Cui bono? question. Such a view of cultural evolution doesn't deny the possibility of moving to what might be called a mind's-eye perspective of evaluation; it is precisely what makes such a transition--without any help from skyhooks--possible.


Boone, James L, and Eric Alden Smith, 1998, "A Critique of Evolutionary Archeology," Current Anthropology. [special issue, supplement, June, 1998]

Boyd, Robert, and Richerson, Peter J., 1985, Culture and the Evolutionary Process, Chicago and London: Chicago University Press.

Boyd, Robert, and Richerson, Peter J., 1992, "Punishment Allows the Evolution of Cooperation (or Anything Else) in Sizable Groups," Ethology and Sociobiology, 13, pp171-95.

Cavalli-Sforza, Luca, and Feldman, Marcus, 1981, Cultural Transmission and Evolution: A Quantitative Approach, Princeton, NJ: Princeton University Press.

Dawkins, Richard, 1976, The Selfish Gene, (2nd edition, 1989), Oxford: Oxford University Press.

------ 1993, "Viruses of the Mind," in Bo Dahlbom, ed., Dennett and his Critics, Oxford: Blackwell.

Dennett, Daniel C. 1998, "Snowmobiles, horses, rats, and memes," (a comment on "A Critique of Evolutionary Archeology," by James L. Boone and Eric Alden Smith) Current Anthropology, [special issue, supplement, June 1998]

---------- forthcoming, "The Evolution of Evaluators" in a volume of the Siena workshop on evolutionary economics.

Diamond, Jared, 1997, Guns, Germs and Steel,

Lumsden, C. and Wilson, E. O. 1981, Genes, Mind and Culture, Cambridge, MA: Harvard University Press.

Pinker, Steven, 1997, How the Mind Works, New York: Norton.

Ridley, Mark, 1995, Animal Behaviour (2nd edn), Boston: Blackwell Science.

Sober, Elliott and Wilson, David Sloan, 1998, Unto Others: The Evolution of Unselfish Behavior, Harvard University Press.

Wilson, E. O., 1978, On Human Nature, Cambridge, MA: Harvard University Press.

1. Parts of this section are adapted from Dennett, forthcoming.

2. Such organisms need not be deemed to be making conscious decisions, of course, but the rationality, such as it is, of the "decisions" they make is typically anchored to the expected benefit to the individual organism. See Sober and Wilson (1998) for important discussions of gene, individual, and group benefits of such decision-making.

3. Sober and Wilson (1998) note that there is a gap in their model of cultural evolution: "We can say that functionless [relative to human individual and group fitness] behavior should be more common in humans than other species, but we cannot explain why a particular functionless behavior has evolved in a particular culture. That kind of understanding probably requires detailed historical knowledge of the culture, and it may turn out that some behaviors evolved mainly by chance." p171.

4. Strictly speaking, to the reproductive prospects of the fluke's genes (or the fluke's "group"'s genes), for as Sober and Wilson (1998) point out (p18) in their use of D. dendriticum as an example of altruistic behavior, the fluke that actually does the driving in the brain is a sort of kamikaze pilot, who dies without any chance of passing on its own genes, benefiting its [asexually reproduced] near-clones in other parts of the ant.

5. Boyd and Richerson (1992) show that "Virtually any behavior can become stable within a social group if it is sufficiently buttressed by social norms." (Sober and Wilson, 1998, p.152)

6. In fact in most of the brief, shallow discussions of the Lamarckian nature of cultural evolution that I have seen, it is never made clear which entities were deemed capable of transmitting acquired characteristics. Sometimes, I suspect, the objector had dimly in mind the strictly irrelevant fact that human hosts can transmit to other human hosts cultural items that they themselves had acquired during their lifetimes. That is not Lamarckianism at all.

7. This section is adapted from Dennett, 1998.

8. The meme's-eye perspective offers many other points of theoretical leverage, but those are topics for another occasion.