Hi, I'm Tim Tyler, and today I'll be discussing popular misconceptions
about memetics.
Introduction
Memetics is the name given to the study of cultural evolution by
Richard Dawkins. It is one of the most misunderstood parts of Darwin's
legacy - and that's saying something!
Unlike most misunderstandings of evolution, misunderstandings of
memetics are common among ordinary scientists and biologists. Some are
the results of mis-steps by the memetic pioneers; some are the result
of memetics being a relatively young and little-known science; some
are the result of genuine conceptual difficulties with understanding
the theory; some are the reactions of established scienists, who
forsee a turf war in their own domain with memetics - and some are the
product of ignorance and other human failings.
This particular video will focus on misunderstandings of the whole
concept of cultural evolution.
Meme fitness depends on gene fitness
I remember when I first read The Selfish Gene, I thought: "ah, but
if the memes are deleterious, their host will die - so meme fitness
actually boils down to DNA fitness in practice".
Dawkins correctly dismisses this view in The Extended Phenotype:
Time and again, my sociobiological colleagues have
upbraided me as a turncoat, because I will not agree with them that
the ultimate criterion for the success of a meme must be its
contribution to Darwinian “fitness”. At bottom, they insist, a “good
meme” spreads because brains are receptive to it, and the
receptiveness of brains is ultimately shaped by (genetic) natural
selection. [...]
It is, of course, true that “Memes are utterly dependent upon genes,
but genes can exist and change quite independently of memes”.
But this does not mean that the ultimate criterion for success in meme
selection is gene survival. It does not mean that success goes to
those memes that favour the genes of the individuals bearing them. To
be sure, this will sometimes be so. Obviously a meme that causes
individuals bearing it to kill themselves has a grave disadvantage,
but not necessarily a fatal one. Just as a gene for suicide sometimes
spreads itself by a roundabout route (e.g. in social insect workers,
or parental sacrifice), so a suicidal meme can spread, as when a
dramatic and well-publicized martyrdom inspires others to die for a
deeply loved cause, and this in turn inspires others to die, and so
on.
However, this remains one of the most common misunderstandings of
memetics I encounter.
One pathogen strategy is to use many of the host's resources as
quickly as it possibly can. That strategy can be seen in Ebola. It doesn't
need to benefit its host to spread. So it is with some memes.
Another pathogen strategy is to sterilise the host, and to divert its
reproductive resources towards propagating the virus. That strategy
can be seen in some priests - who are sterilised by their memes.
Culture doesn't evolve, it is designed
To start with, a soundbite from Eliezer Yudkowsky:
[footage of Eliezer Yudkowsky]
I'll let Stephen Pinker be the spokesperson for this one:
Dawkins himself used the analogy to illustrate how natural selection
pertains to anything that can replicate, not just DNA. Others treat it
as a genuine theory of cultural evolution. Taken literally, it
predicts that cultural evolution works like this. A meme impels its
bearer to broadcast it, and it mutates in some recipient: a sound, a
word, or a phrase is randomly altered. Perhaps, as in Monty Python's
Life of Brian, the audience of the Sermon on the Mount mishears
“Blessed are the peacemakers” as “Blessed are the cheesemakers.” The
new version is more memorable and comes to predominate in the majority
of minds. It too is mangled by typos and speakos and hearos, and the
most spreadable ones accumulate, gradually transforming the sequence
of sounds. Eventually they spell out, “That's one small step for a man,
one giant leap for mankind.”
I think you'll agree that this is not how cultural change works. A
complex meme does not arise from the retention of copying errors. It
arises because some person knuckles down, racks his brain, musters his
ingenuity, and composes or writes or paints or invents something.
Granted, the fabricator is influenced by ideas in the air, and may
polish draft after draft, but neither of these progressions is like
natural selection. Just compare the input and the output — draft five
and draft six, or an artist's inspiration and her oeuvre. They do not
differ by a few random substitutions. The value added with each
iteration comes from focusing brainpower on improving the product, not
from retelling or recopying it hundreds of thousands of times in the
hope that some of the malaprops or typos will be useful.
To a memeticist, such deliberate changes are a type of non-random
mutataion. Some of them are macro-mutations - and they are certainly
nowhere near as random as mutations of DNA usually are - but they are
still mutations. In no way does the non-randomness of mutations
invalidate the basic ideas of memetics.
Also, Pinker's reference to "polishing draft after draft" often refers
to a process that may itself be strongly evolutionary in character -
frequently, if you "dismantle" such a mutation, you will find
another iterative evolutionary process inside it.
The analogy between memes and genes breaks down on close inspection
Take the meme controversy. The disputants take the
main issue to be whether culture is highly analogous to genes or not.
If so, then their evolution is to be explained by fitness, if not,
Darwinism is useless. If we are correct, this debate is an utter red
herring. The proper approach is to recognize that the analogy between
genes and culture is quite loose, and to build up a theory of cultural
evolution that takes into account the actual properties of the
cultural system.
Memes are not merely analogous to genes. They are literally a
type of gene. Memes are genes that are not made out of DNA. The
relationship between memetic evolution and nucleic evolution is
not an analogy. They are both instances of replicator dynamics.
In both cases you have inheritance, variation and selection. These are
both instantiations of a Darwinian process. Yes, there are differences
between memetic and nuclear evolution - but the underlying darwinian
dynamics are identical.
Evolution is poorly seen as being a composite of two different types
of evolutionary process interacting with each other - rather it is one
process, operating on a system with multiple types of replicator.
Meme evolution is not part of biological evolution
This is a matter of definition. Biology is the study of life.
Evolution is changes in the heritable traits of a population over
time. According to those definitions, cultural evolution is
part of biological evolution. Nowhere in the definition of
"evolution" does it say that inheritance must be via DNA. Nowhere
in the definition of "trait" does it say that circumcised penises
do not count.
"Meme" is technobabble for "concept"
Here's Ernst Mayr, in 1997:
In neither his definition nor the examples
illustrating what memes are does Dawkins mention anything that would
distinguish memes from concepts.
One good thing about the term "meme" is its link to the term "gene" -
which immediately conjours up the intended association. The
term "concept" does not do this. This association helps people to
grasp the basic idea of cultural evolution.
Memetics has little predictive power
Here's John Maynard-Smith:
My own suspicion is that these structural differences
between culture and genetics will inevitably limit the usefulness of
the kind of theory presented in this book. The explanatory power of
evolutionary theory rests largely on three assumptions: that mutation
is non-adaptive, that acquired characters are not inherited, and that
inheritance is Mendelian—that is, it is atomic, and we inherit the
atoms, or genes, equally from our two parents, and from no one else.
In the cultural analogy, none of these things is true. This must
severely limit the ability of a theory of cultural inheritance to say
what can happen and, more importantly, what cannot happen.
It is curious to see the idea that randomness leads to
predictability. The randomness of mutations, introduces a
significant quanity of noise into nuclear evolution. That makes it
harder for it to generate reliable predictions. To the extent
that mutations in cultural evolution are less random, that makes its
predictions less noisy, and more likely to be
accurate.
It is true that there are likely to be more possible paths between any
two points in design-space if you are allowed to use the tools of
cultural evolution to produce the intermediate variants. However, the
additional power of cultural evolution means that an optimisation
process is more likely to converge on a desired target with cultural
rather than with nuclear evolution - and so cultural evolution is
more predictable.
So: Maynard-Smith doesn't exactly make a convincing case here.
However, let's assume for a moment that his conclusion is true - and
that it is harder to make predictions with cultural evolution
than it is with biological evolution.
So what? Theories of cultural evolution are not in competition with
theories of biological evolution - they compete with other theories of
cultural change that are less inspired by Darwinism. So: even if the
conclusion was true, the objection is not a pertinent one.
Human culture is not alive
I don't see how someone can subscribe to memetics and fail to take
seriously the section where Nicholas Humprey is quoted in
The Selfish Gene as saying:
Memes should be regarded as living structures - not
just metaphorically, but technically.
For most people, the idea that all human culture is alive represents a
radical redefinition of what it means to be "alive". However it is a
central idea of memetics - and taking the idea seriously
leads to many of its important insights.
Take Linux, for example. Where is its genotype? What does its
phenotype look like? What resources does it take in? What waste does
it spit out? What is it a predator on? What predates on it? What do
its parasites look like? Does it act like a parasite itself? Where are
its ancestral influences. Does it have a split between germ and
soma? Where are its sensors? Where are its actuators? Where does its
metabolism take place? Who are its mutual symbionts? What error
correction mechanisms does it use to preserve its genome. Does it have
an immune system?
Without regarding Linux as being alive, these types of question do
not make much sense.
Memes are not genes
That is a matter of definition. If you adopt a definition of gene
based on information-theory, then memes usually are a subset
of genes. You often hear people contrasting memes and genes -
as though the term "gene" referred to "nucleic-acid replicator". From
the information-theory perspective, that is loose talk. It would be
very bad to have a definition of gene that excludes early
organisms, aliens, and synthetic life.
Here ends my list of memetic misunderstandings. Enjoy!