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Common misunderstandings of
memes (and genes)
The promise and the limits of the genetic analogy to cultural
transmission processes
Francisco J. Gil-White
fjgil@psych.upenn.edu ; http://www.psych.upenn.edu/~fjgil/
Assistant Professor of Psychology
University of Pennsylvania
3815 Walnut Street, Suite 400
Philadelphia PA 19104-6196
Word Count: Abstract = 248 words; Main text = 12,313;
References = 1,154; Entire Text = 13,903.
Short Abstract: ˜Memetics™ suffers from conceptual confusion
and not enough empirical work. This paper attempts to attenuate
the former problem by resolving the conceptual controversies. I
criticize the overly literal insistence”by both critics and
advocates”on the genetic analogy, which asks us to think about
memes as bona-fide replicators in the manner of genes, and to see
all cultural transmission processes as ultimately for the
reproductive benefit of memes, rather than their human vehicles.
A Darwinian approach to cultural transmission, I argue, requires
neither. It is possible to have Darwinian processes without genes,
or even close analogues of them. The cognitive mechanisms
responsible for social-learning make clear why.
Long Abstract: ˜Memetics™ suffers from conceptual confusion
and not enough empirical work. This paper attempts to attenuate
the former problem by resolving the conceptual controversies,
which requires that we not speculate about cultural transmission
without being informed about the cognitive mechanisms
responsible for social learning. I criticize the overly literal
insistence”by both critics and advocates”on the genetic
analogy, which asks us to think about memes as bona-fide
replicators in the manner of genes, and to see all cultural
transmission processes as ultimately for the reproductive benefit
of memes, rather than their human vehicles. A Darwinian
approach to cultural transmission, I argue, requires neither. It is
possible to have Darwinian processes without genes, or even close
analogues of them. The insistence on a close genetic analogy is in
fact based on a poor understanding of genes and evolutionary
genetics, and of the kinds of simplifications that are legitimate in
evolutionary models. Some authors have insisted that the only
admissible definition for a ˜meme™ is ˜selfish replicator.™
However, since the only agreement as to the definition of ˜meme™
is that it is what gets passed on through non-genetic means, only
conceptual confusion can result from trying to make a hypothesis
into a definition. This paper will argue that, although memes are
not, in fact, ˜selfish replicators,™ they can and should be analyzed
with Darwinian models. It will argue further that the ˜selfish
meme™ theoretical calque imported from genetics does much more
to distort than enlighten our understanding of cultural processes.
KEYWORDS: Cultural transmission, culture, evolutionary
genetics, meme, memetics, replicator, social-learning.
Given an incredibly simplistic notion of genes, memes are not in
the least like genes. . .One problem with interdisciplinary work is
that any one worker is likely to know much more about one area
than any of the others. Geneticists know much more about the
complexities of genetics than of social groups. Conversely,
anthropologists and sociologists tent to be well-versed in the
details of social groups. To them genetics looks pretty
simple.”Hull (2000:46)
Many of the claims made about memes could be false because the
analogy to genes has not proven productive.”Aunger (2000:
Introduction
Should we demand that ˜memes™ be exactly like genes if we are to
apply Darwinian tools of analysis to culture? No.
The formal similarities between genes and what (after Dawkins
1989[1975]) are now called ˜memes™”the units of cultural
transmission and evolution”suggest cultural transmission
processes are ripe for Darwinian analysis. A vigorous debate is
emerging over how to think about ˜memes™ (for a recent
compendium of views see Aunger 2000). This is an evolutionary
but also cognitive issue because memes are stored in human
brains.
New fields will always use analogies and borrowed yardsticks,
and these can be a source of fresh insights, but also cause
misunderstanding. The yardstick which requires ˜memes™ to be
essentially identical to genes if Darwinian analyses are to apply is
a source of much confusion. This regrettable error is advanced by
both critics and defenders of ˜memetics™ and”to boot”the
specific arguments are often based on a poor understanding of
genes and evolutionary genetics. The standard chosen is therefore
not only erroneous but would indict evolutionary genetics as well
(genes, it turns out, are not sufficiently like ˜genes™ either!).
There are too many insistent definitions of ˜meme™”typical in a
new research program given that careers (especially in social
science) are often boosted by getting particular definitions
adopted. The prize is large because the term ˜meme™ is on
everybody™s lips. If definitions were advanced only with
conceptual progress in mind, this would be fine. But here, more
than in other fields, the various protagonists must be aware that
the contest is memetic, yielding a tendency to produce ˜catchy™
definitions that ˜sell well™ at the expense of conceptual advance
and scientific utility.
The definition of meme as a ˜replicator™ is very catchy. Introduced
by Dawkins (1989[1975]), and developed by Dennett (1995) and
Blackmore (1999, 2000), it has helped mobilize our intuitions for
population-driven processes involving genes, which are bona-fide
replicators producing perfect descendant copies of themselves. As
a heuristic device there is nothing wrong with this. But as a
statement of what Universal Darwinism is”i.e. find a replicator,
then apply Darwinism”it is a garden path. And a tortuous one.
Consider that Blackmore (2000:26) says œmemes are replicators,�
but on the preceding page claims that, œAs long as we accept that
people do, in fact, imitate each other, and that information of
some kind is passed on when they do, then, by definition, memes
exist.� By definition? By definition ˜replication™ takes place when
perfect copies are produced, not when œinformation of some kind
[my emphasis] is passed on¦� Proponents of memetics who
uphold the ˜gene standard™ must weaken and mutilate the meaning
of ˜replication™”which they take to result from ˜imitation™”in
order to claim that memes are ˜replicators™ and that, since they
are, Darwinism applies. They insist, therefore, not on the concept
˜replication™ but on the word, the use of which is assumed
magically indispensable to the possibility of Darwinian science.
But this is absurd.
Critics of memetics who also uphold this same ˜gene standard,™ on
the other hand, stick closely to the definition of ˜replication™ as
˜perfect copying,™ and this is good (why butcher the language?).
However, they fetishize the concept, for they accuse that the poor
copying fidelity of memes”i.e. memes are not, after all,
replicators”supposedly makes Darwinian analyses to culture
inapplicable in principle. In my view, these critics, as much as the
proponents, are chasing a mirage. Replication is not necessary for
cumulative adaptations through selective processes (Boyd &
Richerson 2000:153-158), and is therefore not the standard both
critics and proponents are looking for. Replication is a red
herring.
The ˜selfish meme,™ like its ancestor the ˜selfish gene,™ is another
catchy idea. It answers the question cui bono? by saying that the
unit being transmitted”the meme”is the ˜entity™ which
˜benefits™ in the cultural selective process. Again, this began with
Dawkins (1983:109), who stated that a meme is œa unit of cultural
inheritance¦naturally selected by virtue of its¦consequences on
its own survival and replication,� and again developed by Dennett
and Blackmore. In this picture œWe humans. . .have become just
the physical ˜hosts™ needed for the memes to get around. This is
how the world looks from a ˜meme™s eye view™� (Blackmore
1999:. In a manner parallel to the ˜gene™s eye view,™ we are here
supposed to interpret every meme that succeeds at proliferating as
having done so by dint of being well designed for proliferation.
Cultural selection is reduced to the continuous editing of meme
content until memes end up optimally designed for colonizing
human brains. I will argue that only some rather specialized kinds
of memes satisfy this analytical calquing from genetics to culture.
But, again, this does nothing to wreck the applicability of
Darwinian analysis or the usefulness of thinking in terms of
memes”it merely indicts the fetishizing of the genetic analogy.
Reducing cultural transmission to ˜selfish memes™ requires that
we ignore much of social-learning cognition and miss most of the
picture.
It should be obvious this far that I feel no compunction to accept
Dawkins™ (1989), Dennett™s (1995), and Blackmore™s (1999)
definition of ˜meme™ as selfish replicator. A recent compendium
of views (Aunger 2000) makes it clear that neither do many
others. It is best not to insist on a research program that rises or
falls on whether memes defined as selfish replicators exist. That
is a careerist semantic game that tries to assume or impose as a
definition something that must be investigated, and such a game
does not advance the science of cultural transmission”a science
that will be carried out anyways because we must.
Most of us seem to accept the Oxford English Dictionary™s
definition, which says: ˜an element of culture that may be
considered to be passed down by non-genetic means.™[1] So
˜selfish replicator™ I will treat as a hypothesis about what the stuff
that gets transmitted through non-genetic means is like. The
relevant questions, then, are: (1) does this stuff look like a selfish
replicator?; (2) If not, does this really make Darwinian analyses of
culture impossible? Related questions are: (3) if they don™t
replicate, is it impossible to find the boundaries of memes?; and
(4) can we import from biology, willy-nilly, the ˜selfish gene™
idea? I will answer œno� to each of these questions. But I will still
call what is transmitted culturally a ˜meme,™ and so”I will bet
my house”will everybody else. The term ˜meme™ has already
been selected for, so rather than forcing its meaning to coincide
with a particular hypothesis about cultural transmission, let us do
some science.
I. What is required for genetic
cumulative evolution?
Darwinian systems involve simple and blind algorithmic
processes that nevertheless produce gradual accumulation of
(sometimes very complex) adaptive design. They have three main
requirements: information must be able to leave descendant
copies (inheritance), new information should be routinely
generated by some process (mutation), and there should be forces
responsible for causing some items of information to leave more
descendants than others (selection).
Genes satisfy all three. They are inherited through reproduction;
new genes are routinely created because of occasional copying
mistakes, or ˜mutations™, during DNA duplication; and a gene,
through its effect on its carriers, affects the probability that it will
increase in number. Thanks to selection and inheritance, when a
particular gene causes increased reproductive success, more
copies of it are passed on, and its relative frequency in the
population increases (absent frequency dependent effects,
eventually the whole population will have it). Thanks to mutation,
new alternative genes get generated which occasionally amount to
improvements, allowing the population to continue to evolve.
Cumulative genetic adaptations are possible because (1) genetic
mutations typically introduce incremental rather than massive
changes, and (2) the mutation rate for genes is low. It is these
latter two requirements for cumulative evolution in genetic
systems that inform some scholars™ intuitions that
˜replication™”that is, high-fidelity copying”is crucial to
cumulative evolution through memes as well, which intuitions
then damn Darwinian approaches to culture if memes are found
not to replicate. For this reason these two requirements deserve
further attention here.
Massive change is by definition the opposite of the accumulation
of design, where each successive design change is a minor
alteration on the margins of the previous template. But should we
expect organic evolution to consist of small, incremental changes?
Yes. The space of maladaptive designs is vast relative to the space
of adaptive ones, so random changes to any current design (and
mutations are random) are unlikely to cause adaptive
improvements. Imagine that a monkey types a character at random
as I am writing this essay. Will it improve? Without vanity, I can
say that the chances are exceedingly low. A random typo is
unlikely to yield English, let alone better English. But should the
monkey press a key which launched a program to rearrange all of
the letters in my essay, then he would be infinitely less likely to
improve it”slim as his chances were anyway. In population-
driven processes, for a novelty to last longer than an instant, it is
typically constrained to cause a small modification.
Mutations must also be infrequent because, unless designs are
relatively stable across time, we cannot get cumulative evolution.
Suppose the offspring of A™s are mostly non-A™s. Even if A
reproduces better than its competitors B and C, this cannot have
an evolutionary consequence because the information responsible
for A™s reproductive prowess is almost always lost after
reproduction. On the contrary, if an A typically begets another A,
then A™s higher reproductive success will soon make everybody in
the population an A (absent frequency-dependent effects). Later,
when a rare mutation results in a slight improvement to ˜A
design™”let us call the new design A°”these A° mutants will
outreproduce mere A™s and the population changes again (but only
slightly).
This covers the intuitive basics of genes as replicators allowing
for cumulative cultural evolution. But how similar to genes are
memes? Well, memes certainly have the properties of inheritance,
mutation, and selection. We constantly acquire and learn things
from each other through social interaction, so in a broad sense at
least it makes sense to say that the information I possess can
create a ˜descendant copy™ in you (inheritance). People can make
mistakes when acquiring information, and can also have stupid or
bright novel ideas, which leads to new items of information
(mutation). And some ideas are more popular than others, so they
are copied more, stored longer, and rebroadcast more often, which
in turn means they leave more descendants than competing ideas
(selection). What makes some ideas more ˜popular™ than others
are the properties of human social-learning psychology. This is
not the only force acting to favor certain memes over others, but it
is a very important one and I shall restrict myself to it here.
So much for intuitively stated formal similarities. The devil, as
usual, lurks in the details. To many critics, the dangerous phrase
above is œin a broad sense¦information can create a ˜descendant
copy.™� How broad? How similar must ancestor and descendant
memes be?
Some assert that selectionist approaches cannot work because
memes are not true replicators, making cumulative evolution
impossible (e.g. Sperber 1996; Boyer 1994). Others, however,
have not considered this a problem and proceeded to build
Darwinian selectionist models that in their fundamental
assumptions are quite similar to those used in evolutionary
genetics, but adapted for cultural idiosyncrasies (e.g. Boyd &
Richerson 1985; Lumsden & Wilson 1981; Cavalli Sforza &
Feldman 1981; for a review, see Feldman & Laland 1996). As
Laland & Odling Smee (2000:121) put it: œFor us, the pertinent
question is not whether memes exist. . .but whether they are a
useful theoretical expedient.� Their critics, however, will counter
that such models do not help us explain human cultural processes
because the units employed are nothing like what exists in real-
life cultural transmission. To find out who is right, we need first
to examine closely whether it matters that memes are poor
replicators.
II. Do memes mutate too
much?
To Dan Sperber (1996), contagious pathogens such as viruses are
a better analogy than genes for understanding the spread of
cultural information. Populations of brains are infested in
successive ˜epidemics™ of memes (which Sperber invariably calls
˜representations™”a favorite term in the cognitive literature). He
cautions, however, that the analogy can be taken only so far.
. . .whereas pathogenic agents such as viruses and bacteria
reproduce in the process of transmission and undergo a mutation
only occasionally, representations are transformed almost every
time they are transmitted. . .”Sperber (1996:25)
. . .recall is not storage in reverse, and comprehension is not
expression in reverse. Memory and communication transform
information.”Sperber (1996:31)
For example, does anybody ever retell a story exactly? No, and
this is Sperber™s point.
In the case of genes, a typical rate of mutation might be one
mutation per million replications. With such low rates of
mutation, even a very small selection bias is enough to have, with
time, major cumulative effects. If, on the other hand, in the case
of culture there may be, as Dawkins [1976] acknowledges, ˜a
certain œmutational� element in every copying event,™ then the
very possibility of cumulative effects of selection is open to
question.”Sperber (1996:102-103)
It is important to see exactly what the argument is. Genes are very
stable across generations because they very rarely make copying
errors during duplication”hence, for the most part, they
replicate. As observed above, this allows cumulative genetic
adaptations to emerge because small, cumulative changes can
only be added if there is an overall template which remains”for
the most part”stable. There is nothing absolute about the
acceptable rate of mutation, of course. Rather, this is always
relative to the strength of selection. For example, even if there is a
moderate rate of mutation, cumulative evolution will still happen
if the selective process culls suboptimal variants fast enough that
the favored design is stable at the populational level, and from
generation to generation. G.C. Williams (1966) made this
principle famous in his definition of an ˜evolutionary gene,™ which
is œany hereditary information for which there is a favorable or
unfavorable selection bias equal to several or many times its rate
of endogenous change.� This definition was taken willy-nilly by
Dawkins and applied to his definition of the ˜meme,™ and recently
stated very clearly by Wilkins (1998::
A meme is the least unit of sociocultural information relative to a
selection process that has favorable or unfavorable selection bias
that exceeds its endogenous tendency to change.
Sperber is accepting this move to assume (1) that ˜replicators™ are
the things to look for; (2) that Dawkins™ reinterpretation of
Williams gives the universal definition of a replicator, and (3) that
Darwinian analyses will apply to memes only if they can satisfy
this definition. In fact, Sperber eagerly forces the issue by ruling
that any other conceptualization of ˜the meme™ is trivial (Sperber
2000:163). His stance is therefore that cumulative adaptations
through cultural selection are possible only if we can find bona-
fide cultural replicators. But memes in fact mutate in every single
act of transmission, so he concludes that cultural selection cannot
conceivably act fast enough because the meme™s dizzying rate of
endogenous change creates a ceiling effect (Atran 2001 echoes
this argument). Sperber therefore believes that we must
understand how cognitive processes of information storage and
retrieval cause mutations in particular and systematic directions.
With this information, we can build (orthomemetic?) models of
directed mutation rather than selectionist models (Sperber
1996:52-53, 82-83; 110-112) of cumulative change.
There is some irony in this. Hull (2000:47) quotes the above
definition by Wilkins approvingly as a starting point for a science
of memetics that he optimistically believes to be possible,
although he fully expects œhowls of derision� to come from
unreasonable critics who will accuse this definition of not being
sufficiently œoperational.� Something very different has already
happened, however! A prominent critic of selectionist approaches
to culture”Sperber”has eagerly embraced that very definition in
order to explain why selectionist approaches to culture are
supposedly impossible.
It would seem as though either Hull or Sperber must be wrong, for
they agree on how to define units of cultural processes that would
be legitimately Darwinian, but they reach exactly opposite
conclusions as to whether human culture passes or fails the test.
However, I believe they are both mistaken because they are
sparring on the wrong battlefield. The standard chosen, rather than
enlighten, blinds us to the general requirements for a Darwinian
system by insisting narrowly on the terms of one particular
solution to them”the genetic one”as if this were the only
possibility.
I shall accept Sperber™s point that the mutation rate for memes is
1: they mutate in every act of transmission. And I will agree, too,
that often they are systematically biased. But this is neither here
nor there. What matters is how big these mutations are, and how
strongly biased in particular directions, as we shall see.
III. ˜Replication™ is a red
herring
Sperber™s argument may seem intuitively appealing, but I think it
is specious. Near-perfect copying fidelity is certainly important in
genetic selection, but it is not a requirement for any Darwinian
system. If the high rate of mutation is not the meme™s only
distinction, then perhaps its other idiosyncrasies make it possible
for regularly imperfect”or even invariably imperfect”meme-
copying to support the emergence of cumulative adaptations.
I shall make the case with a toy example. But first, a few
preliminaries. In genetics, a ˜locus™ is the physical location of a
˜gene™ on a chromosome. This is where the information ˜for
something™ can be found. If we are talking about, say, the ˜eye-
color™ locus, then the gene found there may be the ˜brown-eye™
gene, or the ˜blue-eye™ gene, and so forth. What is the analogue in
memetic transmission? For example, imagine something like, say,
a tennis-serve ˜locus™. Whatever is in your tennis-serve locus
causes your behavior when beginning a new point in tennis. There
are in principle a vast number of different behaviors that people
could store at the tennis serve locus (just as there are many
different sequences of nucleotides that may be stored at the
chromosomal eye-color locus). Waving hello to your mom, or
baking a bread, would be ruled illegal by the judges, but in
principle this does not prevent you from storing such information
at that locus (just as a random and useless sequence of nucleotides
could, in principle, be stored at the eye-color locus).
It hardly matters that the tennis-serve locus may not be physically
located in the same piece of brain for every individual. To insist
on this is to push the genetic analogy to an absurd extreme where
it begins to straight-jackets thought rather than inspire insights.
The relevant and crucial similarity is functional, not physical: if
individuals recognize that an item of information becomes
relevant when, in a game of tennis, a new point is beginning, then
the ˜cultural locus™ has all the requisite functional similarity to the
genetic locus that we need. In cognitive terms, the cultural ˜locus™
is a tag plus retrieval function”it is a matter of categorization
rather than physical location in the brain. The information
retrieved at the start of a new tennis point is that which I tag as
˜tennis serve™. Waving to my mom or baking a cake have not been
tagged this way (even though, in principle they could be), and,
since they have not been, they do not compete to ˜occupy™ my
tennis serve ˜locus.™ The true alleles of my current serve,
therefore, are other behaviors which I also tag as ˜tennis serves™
because some individuals in the population perform them in the
context of beginning a point in a tennis match. I may choose to
acquire one of these later on, and in so doing will replace my
current serve.
These obvious functional similarities readily dismiss the criticism
that, because memes do not have the same kind of physical reality
as genes, selectionist approaches to culture are a nonstarter. We
are not talking here of the duplication of exact neuronal structures
analogous to the duplication of exact nucleotide sequences in
DNA, but we are speaking of the duplication of a certain
behavior, understood to belong in a certain context, and in
competition with other behaviors also understood to be candidates
for the same context. The lack of similarity in the material basis
of genes and memes is not a problem.
A. The right mix of stability and
variation
To see whether a meme™s inability to properly replicate makes
cumulative cultural adaptations are impossible, we must examine
the full spectrum of theoretical possibilities.
Suppose that in our population, Bob™s serve is the most attractive,
and seeing it performed gets people excited to make changes in
their own tennis-serve loci. There is a continuum of different
things that could happen, bounded by two extremes. At one
extreme”replication”people acquire precisely the same content
that is in Bob™s own locus. For example, you acquire the exact
same top-spin service with a slight jump that Bob favors. At the
other extreme”causation of random changes”people rewrite the
information in their locus such that it typically bears no
resemblance to Bob™s serve. Here, for example, you might ˜write™
into your tennis serve locus the idea that you should wave at mom
when up to serve.
Please take note that I am not following the information in the
brain here, although of course it is necessary for the process. What
I am keeping track of here is the actual behaviors, and I am
completely ignoring the question of what particular information
content in the brain may be causing them. The latter is not always
unimportant (Gil-White 2002a), but it does not concern me in the
present analysis, and it is irrelevant to the points I will make.
When I talk about ˜replication failure,™ what I mean here is the
inability of the copier to perform a serve that is identical to Bob™s.
Let us look first at the causation of random changes. This will
look silly, but we cannot gain the proper insights until we examine
the full spectrum of possibilities. As silly as it sounds, suppose I
put ˜wave at mom™ in my tennis serve locus after watching Bob™s
top-spin serve. You will put randomly different, but typically
equally dissimilar, information to Bob™s serve in your own tennis
serve locus. What will happen? We are assuming that it is the
content (i.e. the sequence of motions) involved in Bob™s serve that
make it attractive, in turn precipitating changes in the tennis-serve
loci of other people. Given this, I myself (who now wave at mom
when I ˜serve™)”and all others who randomly changed the
information at their tennis serve loci after watching Bob”are not
similarly beacons of change; our new ˜tennis serves™ look nothing
like Bob™s and they therefore get nobody excited (and mostly
irritate the judge because they are not admissible). Bob™s serve
has not become more common, nor has the mean serve of the
population moved in the direction of Bob™s serve. Since evolution
is about statistical changes in a population, the fact that this
process does not produce reliable directional movement in the
population™s mean serve implies that this process cannot lead to
cumulative design changes. After all, the first requirement for
cumulative adaptive design is the possibility of directional
change.
Now consider the other extreme. This will look silly too. Here,
watching Bob™s serve produces verbatim replicas in observers™
tennis-serve loci. People copy perfectly, so there is never any
mutation”not ever. What happens? Because Bob™s is the most
attractive serve, all of the people who now have Bob™s serve in
turn become models for other people, who again copy the serve
precisely and so forth. Bob™s serve spreads until everybody is
serving identically. Here, too, selection cannot lead to cumulative
design changes because the serves are all identical to Bob™s. The
future will be spent forever more serving exactly like Bob, by
everybody. No other serves will ever emerge because nobody ever
makes a copying mistake.
We see that at either end”random changes, or perfect replication
(100% copying fidelity)”there can be no accumulation of
adaptive design. So this can occur only somewhere ˜in the
middle™, where descendant changes are relatively similar to the
˜parent™ stimulus, but somewhat different. There are two ways in
which this can happen: (1) descendant serves are always identical
to the parent, except that every once in a long while there will be
an accidental difference; or (2) the descendant serves are always
accidentally different from the parent serve, but jump around
relatively closely to the average of copying accuracy. In both
cases we get more attractive future serves by making marginal
changes to Bob™s, which in turn makes the marginally improved
serve the new model (and this is what allows for cumulative
adaptation). I examine each in turn.
(1) Copying involves mistakes only once in a long while. Here the
information ˜written™ in a person™s tennis-serve locus is a pristine
replica of the ˜parent™ serve. There is a very small probability of
replication failure so, very rarely, a random modification results.
Such modifications will typically make Bob™s serve less effective
because a tennis serve is a complex behavior where many
variables must be kept within narrow ranges to ensure success. I
am assuming that only effective serves are attractive, and so most
random changes will result in less attractive serves. But very, very
occasionally, a random copying mistake begets a more
effective”and therefore more attractive”serve, which then
displaces Bob™s as people now begin making perfect replicas of
the improved serve. Many iterations of this cycle will lead to ever
better serves. I have just described a process of accumulation of
adaptive design emerging from cultural transmission that is
exactly parallel to cumulative genetic evolution by natural
selection. Sperber (1996) claims that in order for selection to
produce cumulative design in cultural transmission, the process
should look like this. But let us take a look at a rather different
process.
(2) Copying always involves mistakes, but around an average of
perfect accuracy. This process is illustrated below in fig. 1. Every
time somebody sees Bob™s top-spin serve, the goal is to copy it
exactly, but there is always some error, and thus there is almost
never a perfect copy. However, the errors are relatively small and
not biased in any particular direction, so that Bob™s serve is
obviously the template for all descendant serves. In this scenario,
replication is the occasional exception. However, the population™s
mean serve is still Bob™s, even if no individual serve is a true
replica. The errors amount to a constant introduction of modest
variations, from which a serve superior to Bob™s will emerge, and
which then will become the new model serve”the new template
to copy”for all of us. When that happens, this new serve
becomes the new mean of the population, with a new cloud of
error around it.
If we concentrate on the population mean, it is clear that
cumulative design is taking place. This is not like genetic
evolution by natural selection (where replication is very high
fidelity), but it is certainly the accumulation of adaptive design
due to selection (and it is faster than natural selection because
variants are introduced in every copying attempt).
Bob™s serve


better
serves


new model

Fig. 1. Copying with modest errors. Think of the units in the X-
axis as being very small, so that the distance between the left-most
bar and the right-most bar is not too great”that is, we are
assuming that all serves produced are minor deviations from the
target serve (which is Bob™s).
In the second case just considered replication rarely if ever
happens; the norm is replication failure. It is a good summary
description of the assumptions that go into many of the
selectionist models that Boyd & Richerson (1985) introduced in
their approach. This condition of replication failure as the norm is
what Sperber claims renders cumulative adaptations from cultural
transmission impossible. But we have just seen that it is certainly
conceivable, and this lays bare that replication itself is a red
herring. It is neither here nor there. What cumulative adaptation
requires is (1) sufficient inaccuracy in the production of
descendants such that superior variants can occasionally emerge;
and (2) sufficient accuracy that, at the populational level (the
mean), we can speak of meaningful, directional change (cf. Boyd
& Richerson 2000).
B. Mutations may have consistent biases
But what about directed mutation? This idea posits an attractor,
created by a psychological bias, towards which serves will tend
because the copying mistakes we make are on average in the
direction of the attractor. That is, the mean of our copying errors
will not be zero. Contra Sperber, this is still not a problem”at
least not in principle.
The attractor could be anywhere at all, but we can get our
bearings by again considering the two extremes, namely, (1) when
the attractor is the optimally effective serve, and (2) when it is in a
direction opposite to the optimally effective serve.
(1) The mutation attractor is the optimally effective serve. This
case is illustrated below in figure 2. As before, suppose that every
person tries to copy Bob™s serve exactly, but fails within a cloud
of error with mean zero. A few people, however, can see forward
to the kinds of modifications that would make Bob™s serve even
better, and attempt these. This means that the actual mean ˜error™
for the whole population will be skewed by these innovators in the
direction of the optimal serve. Does this prevent cumulative
adaptive design? No. On the contrary, it speeds up the process that
takes the population to the optimal serve because mutations in this
direction are slightly more likely. The design is cumulative
because foresight does not extend to the optimal serve itself,
merely to slight modifications of observable serves that take them
in that direction.
Bob™s serve


better
serves


Copying mistakes
that result in improvements

Fig. 2. Adaptive mutation bias. In this case the population mean
is closer to the optimum, after copying, than is Bob™s.
(2) The mutation attractor is in a direction opposite to the optimal
serve. This case is illustrated below in figure 3. This could mean,
for example, that there is something about the way it feels natural
to move our bodies that makes us more likely to make errors in a
direction away from the optimally most effective serve. But the
phrase here is more likely. It doesn™t mean that copying errors in
the direction of a better serve never happen. Thus, what happens
is that the mean copying effort results in a serve somewhat lower
in quality than Bob™s, but if the cloud of copying error
occasionally produces a serve better than his, this serve will
become the new target for copiers. This results in a new
population mean that is again less good than the new target serve,
but it is not less good than the previous mean serve in the
population. Thus, the population mean will have moved closer to
the optimal serve despite the fact that the mutation bias always
makes it lag behind its current target.
Bob™s serve


better
serves


Copying mistakes
that result in improvements

Fig. 3. Maladaptive mutation bias. In this case the population
mean is further away from the optimum, after copying, than is
Bob™s serve. However, some copiers will make mistakes to the
right of Bob, and since this yields a better serve, it will become
the model for the next generation.
Only when the attractor is so far away that it prevents the
emergence of any variants better than Bob™s serve would the
emergence of cumulative design be short-circuited, as shown
below in figure 4.
Copying mistakes
that result in improvements


Bob™s serve


better
serves

Fig. 4. Overly strong maladaptive bias. Due to a strong mutation
attractor, the population mean is so far away from Bob™s serve in
a maladaptive direction that better serves practically will never
appear.
The last example above shows that, when directed mutation
occurs, it should be modeled together with selection. The
direction of the system will then result from the algebraic sum of
all the forces considered. We don™t have to decide whether either
mutation or selection is the force to consider in our modeling
exercises. For problems having the structure just considered,
Sperber will be right that constant, directed mutation, prevents
cumulative adaptation only if and when such mutation is (1) not
towards the optimum and, (2) of sufficient strength. This is an
empirical question, and it may be true for some domains and not
for others. But we will not find the answer under the armchair.
But do we have empirical examples of cumulative cultural
adaptations through selection? Yes. Other than tennis serves, we
could name tennis racquets. In fact, we could name anything in
the large domain called ˜technology™. Here design has obviously
accumulated gradually. And even here Sperber™s dictum that
replication is a limiting case rather than the norm is correct
(except in the case of our very modern manufacturing techniques).
One can also point to institutions. Certainly institutions have been
˜constituting™ themselves on paper for a long time, but
institutional organization pre-dates paper. Moreover, though the
rules of an institution may be written, institutional behavior is
always in the (sometimes very) flexible neighborhood of what is
written down, rather than a rigid instantiation of it. In this
sense”as living, breathing organisms”institutions are always
imperfectly copied (for an example, consider that the Mexican
political constitution is”on paper”almost a replica of the
American, on which it was modeled). And yet institutions accrete
cumulative changes. The evidence that they do so adaptively is in
the incontrovertible fact that complex societies have outcompeted
simple ones, and in the fact that different institutional
arrangements have been the key to success in the competition
between different complex societies (McNeil 1963, Landes 1998,
Diamond 1997, Wright 2000). Technological and institutional
change are not the only examples, merely the most obvious ones.
But they occupy much of what is important in cultural evolution,
so they make the case that selectionist approaches will be quite
significant to explaining culture.
Given that cumulative cultural adaptations don™t require memes to
replicate, this was not the litmus test for Darwinian analyses to
culture. And if my critique of gene-analogy fetishism among the
critics of ˜memetics™ is acceptable (for a mathematical
demonstration of my core arguments, see Henrich and Boyd
2002), it simultaneously refutes the arguments of proponents such
as Dawkins, Dennett, and Blackmore, who fetishize the alleged
importance of ˜replication™ for opposite reasons.
IV. ˜Imitation™ is another red
herring
A related point can be made about ˜imitation™ (i.e. what we do
when we copy Bob™s serve). Blackmore insists on imitation as the
memetic process. But she would like to consider a narrative, for
example, a ˜meme.™ And yet, narratives are not transmitted by
imitation. Blackmore (1999:6) gets around this by corrupting the
meaning of ˜imitation™ just as she did with ˜replication™:
Dawkins said that memes jump from 'brain to brain via a process
which, in the broad sense, can be called imitation' (1976:192). I
will also use the term 'imitation' in the broad sense. So if, for
example, a friend tells you a story and you remember the gist and
pass it on to someone else then that counts as imitation.
With such a loose definition of ˜imitation,™ a reader such as
myself cannot understand what standard Blackmore upholds when
she insists that ˜imitation™ is what identifies the subject matter of
˜memetics™ (cf. Plotkin 2000:76-77).
But this is another red herring anyway. We need a handle on the
social-learning cognitive mechanisms which, in combination with
individual-learning processes, are responsible for affecting the
distribution of memes (cf. Plotkin 2000; Laland & Odling Smee
2000). Imitation is important, but we don™t need to fixate on it.
Different domains will involve different processes and will need
mid-level theories particular to them, but œIn every case the
Darwinian population approach will illuminate the process¦�
(Boyd & Richerson 2000:144).
The imitation of a motor act, the acquisition of a native language,
and learning one's culture-specific social constructions have
different developmental trajectories. . .Each is based on different
psychological mechanisms. It is almost certainly the case that the
characteristics each displays in terms of fecundity, longevity, and
fidelity of copying are also different in each case, and different
precisely because each is based on different mechanisms. The
suggestion that œwe stick to defining the [sic] meme as that which
is passed on by imitation� Blackmore (1998), if taken literally, is
an impoverishment of memetics for reasons of wanting to
maintain copying fidelity.”Plotkin (2000:76)
The insistence on imitation, as Plotkin suggests, comes precisely
from this obsession with replication (copying fidelity). Imitation,
narrowly (i.e. properly) understood, is the mechanism that strikes
some observers, Blackmore included, as closest to the production
of carbon copies. So they insist on the word ˜imitation™ because it
confers the cachet of ˜replication,™ which in turn supposedly
grants in exclusivity the legitimacy to undertake Darwinian
analyses. Absurd.
And here again, the critics of ˜memes™ agree with this fetishism of
˜imitation™ only so they can reach the opposite conclusion. Atran
(2001) in a section title, says, œNo Replication without Imitation;
Therefore, No Replication� (because there is no real imitation),
and thus”absent replication”no applicability of Darwinian
selectionist analyses to culture. This is hardly better, and refuting
Blackmore™s error is simultaneously to refute this one. If imitation
and replication are neither here nor there when it comes to
establishing a litmus test for the possibility of a Darwinism of
culture, then one cannot reduce one™s advocacy or skepticism of
this project to whether there is or isn™t imitation and/or
replication.
It is true that some cultural transmission scholars have made much
of ˜imitation™ (e.g. Boyd & Richerson 1985, 1996, 2000;
Tomassello et al. 1993), and they have stressed its indispensability
to cumulative cultural evolution. Less misunderstanding would
result if they said imitation was the ability which initially set
humans along the path of cumulative cultural change, and that
other tricks have since become possible (it is not a coincidence
that when the above authors stress imitation they are comparing
humans to nonhumans). For example, I have recently argued that
language became possible when imitation led to the emergence of
prestige hierarchies (Gil-White 2002). But this emergence of
language now makes prestige-biased transmission often a process
of influence that pushes attitudes back and forth along a
continuum, rather than imitation (Henrich & Gil-White 2001).
Another example: narratives can accrue cumulative changes
through selection, and I doubt that Robert Boyd, Peter Richerson,
or Michael Tomassello will disagree. But narratives don™t spread
through imitation, even if the evolution of imitation was necessary
for the emergence of language, which is indispensable for
narrative. We must distinguish the phylogenetic indispensability
of imitation from its current importance in cultural transmission.
V. Platonic inferences
So far I have ignored the following problem: although individuals
do not make replicas of the memes they try to copy, they do try to.
However, what could their target be? After all, our tennis player,
Bob, never replicates his own serve perfectly either! Bob™s
performance is itself a cloud of error around a mean. So copiers
must be abstracting an ˜ideal Bob serve™”which they try to
emulate”from Bob™s performances. Sperber (1996:62-63)
dismisses this as ˜a Platonist approach™ (indeed Plato would have
liked the argument that we strive to copy not the thing we see, but
its ˜essence™, as we infer it, so to speak). To Sperber, formal
properties cannot be causal.
I believe the opposite. It makes perfect sense that we infer and
abstract an ˜ideal™ serve as Bob™s goal, and then strive for it. For
evolution to have designed our social-learning psychology
otherwise would not have been adaptive, given that the
performances of the people we copy are statistical clouds (cf.
Dennett 1995:358; Dawkins 1999:x-xii; Blackmore 1999:51-52;
Boyd & Richerson 2000). In a selectionist model it is therefore
perfectly valid to define ˜the meme™ as the abstraction for which
Bob strives, and to track the population mean as people try to
copy this abstraction. I do not agree with criticisms that
selectionist models have illegitimately relied on assumptions of
discrete memes (Atran 2001), or that œthe notion of replication
certainly is one idealization too many for models of cultural
transmission� Boyer (1998). The problem being modeled will
determine whether the simplification is legitimate, and many such
models actually include copying error as a parameter anyway.
However, there is no question that there is an important role here
for cognitive psychology and anthropology. We need a better
understanding of how the brain decides which aspects of a
performance are important and which irrelevant. Understanding
such cognitive filters will tell us, for a particular domain, what is
the ˜meme™. But not having yet a good handle on such things is no
obstacle (pace Atran 2002:ch.10) to current selectionist models
(review in Feldman & Laland 1996) for these are concerned with
the formal, emergent properties of Darwinian systems that, by
assumption, are capable of cumulative adaptation, rather than
with the histories of any specific, individual memes. As such, they
teach us how to think about cultural evolutionary processes
involving broadly specified types of (relatively abstract) memes,
and the long run properties of dynamic systems having two
interlocking systems of inheritance: genetic and cultural. What I
have tried to do here is show that the assumption of selectionist
models”that cumulative adaptation is rampant in cultural
transmission”is a very reasonable assumption.
VI. What are the boundaries of
˜a meme™?
Some critics (e.g. Atran 2001) accuse that memes don™t have well-
defined boundaries, but even œwell-disposed� anthropologists
can™t see where to draw them. Maurice Bloch (2000) expresses his
misgivings as follows:
As I look at the work of meme enthusiasts, I find a ragbag of
proposals for candidate memes, or what one would otherwise call
units of human knowledge. At first, some seem convincing as
discrete units: catchy tunes, folk tales, the taboo on shaving
among Sikhs, Pythagoras's theorem, etc. However, on closer
observation, even these more obvious 'units' lose their boundaries.
Is it the whole tune or only a part of it which is the meme? The
Sikh taboo is meaningless unless it is seen as part of Sikh religion
and identity. Pythagoras' theorem is a part of geometry and could
be divided into smaller units such as the concept of a triangle,
angle, equivalence, etc.
Bloch has rather quickly pronounced defeat. These problems are
hardly insurmountable, and they are not any different from similar
conceptual problems faced in evolutionary genetics.
What is ˜the meme™: the whole tune or only part of it? A
Darwinian unit is of whatever size selection favors. This is why in
evolutionary genetics Dawkins (1983:87-89) doesn™t like to insist
on the gene as a cistron (˜start™ codon to ˜stop™ codon). He is right.
The cistron is more useful to molecular biologists. A tune, just
like a cistron, has a starting point and an ending point, and, just
like a cistron, this is a matter of performance, not selection. For
the tune, a musical performance; for the cistron, the construction
of a polypeptide chain. Our intuition that the whole tune is a unit
does not come from an analysis of what people can remember and
what they rebroadcast, about what spreads and doesn™t spread, but
rather from our understanding of the conventions of musical
performances. That the whole tune is a unit of performance does
not make it a unit of selection.
The key point is that there are memes about which things to
perform, and how much of them to perform, and these are of a
different kind, and are found at different cultural ˜loci,™ than the
loci which store tune fragments. At one cultural ˜locus™ we find
beliefs about which piece should be played compete. This locus
can house a finite number of such beliefs; ˜Beethoven™s 5th
deserves to be played™ has consistently triumphed in securing a
spot in it. Another locus is where memes compete to specify how
much of a piece should be played. Here the belief ˜play a piece
from beginning to end™ has fared well against competitors. Thus,
it is because these two memes are successful in their respective
loci that Beethoven™s 5th is played often and in its entirety”not
because the symphony itself is encoded whole in the heads of
listeners! What listeners remember of the piece is stored in yet
another locus where tune-fragments compete to be remembered.
For the most part, only the opening theme survives (it is very
catchy).
That these loci are independent (though not unrelated, of course)
is made evident by the fact that very catchy but tiresome pop-tune
fragments will get remembered so easily that the preference for
the entire song not to be played will spread (at least after the
initial success of the song in question). It is thus possible for the
tune-fragment, on the one hand, and the negative preference for
the song which contains it, on the other, to be simultaneously at
high frequency, and remain so for a while. Try and see if you can
forget ˜The Macarena™ (and tell me honestly whether you would
like to hear it played). Of course, for such a tune-fragment to
persist across the generations, a reasonable fraction of people
must preserve the belief that the piece which contains it ought to
be played. The opening theme to Beethoven™s 5th will probably
continue to make it, but my future children will never know ˜The
Macarena™.
What we have discovered here is that for a meme to spread”here,
the opening theme to Beethoven™s 5th”it needs a favorable
ecology of other memes at other loci (for example, ˜Beethoven™s
5th deserves to be played™; the memes necessary to play a violin;
the meme that violinists should be paid; etc., etc.). This discovery
looks a lot like an earlier discovery: that any gene cannot hope to
prosper unless it is surrounded by a favorable ecology of genes at
other loci in its own organism, and also in the ecology of
phenotypic effects of other organisms™ genes. What else is new? If
this discovery does not hurt the possibility of population analyses
in biology, why should it be fatal for culture?
Yes, the Sikh taboo is more likely to spread and remain stable in
an ecology of religious memes that are congruent with it. Yes,
Pythagoras™ theorem cannot be learned without first possessing
the meme that says what a triangle is. But neither can the gene for
reciprocity spread, for example, unless there are genes already for,
say, social aggregation. None of this is new, or especially difficult.
Another vexing problem raised by the question œwhat are the
boundaries of ˜a meme™?� refers to the level of abstraction. When
somebody tells me a story, and I retell it, I will never give a
verbatim rendition of the story I heard. Many of the details will
change. There are good reasons to think that most of the details
are not even stored in memory (Schank & Abelson 1995). I can
feel the critic pouncing: œAha! There is no stability!� But at what
level? Suppose that the skeleton of the story is very stable. If so,
the fact that story details are not even encoded in the listener™s
brain”and therefore change radically from version to version”is
as worrisome to Darwinian analyses in culture as silent mutations
in the DNA code are to evolutionary genetics (i.e. not at all).
What we need to keep track of is the story skeleton. Changes
there will be the real mutations. I shall ignore further
development of this point here as I will soon give it an article-
length treatment (Gil-White, in prep.).
VII. Meme ˜content™ is not
everything
Recently, Sperber (2000) makes a concession to the point that we
make Platonic inferences but then insists that these are almost
always triggered rather than bootstrapped. Atran (2002, 2001,
1998), and Boyer (1998, 1994) make essentially the same point.
The argument is that observation produces ˜inferences™ which are
best described as the triggering of a pre-existing knowledge
structure. Sperber (2000:165-66) gives the example of language,
interpreted from a Chomskian point of view, œwhere language
learners converge on similar meanings on the basis of weak
evidence provided by words used in an endless diversity of
contexts and with various degrees of literalness or figurativeness.�