Hi, I'm Tim Tyler, and today I'll be discussing more popular
misconceptions about memetics.
This particular video will mostly focus on the views of those who
accept the concept of cultural evolution - but do not think that
memetics is an appropriate model for it.
Lamarckian inheritance is a problem for memetics
That inheritance in cultural evolution is Lamarckian was one of the
points John Maynard-Smith raised. Here is Stephen
Pinker on the subject:
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.
But this won't do. Lamarck, recall, was not just unlucky in his guess
about life on this planet. As far as explaining complex design goes,
his theory was, and is, a non-starter. It is mute about the beneficent
force in the universe or all-knowing voice in the organism that
bestows the useful mutations. And it's that force or voice that's
doing all the creative work. To say that cultural evolution is
Lamarckian is to confess that one has no idea how it works.
Lamarckian inheritance - which I will take to refer to the inheritance
of acqurired characteristics - did not offer an explanation of how
acqurired traits found themselves in an organism's genome. However,
that is not to say that no such explanation could ever be found.
The reason we don't have Lamarckian inheritance in conjunction with
DNA is that the central dogma of molecular biology effectively
prevents the phenotype modifying the genotype. You can't "unbake"
the developmental cake - and recover the genotype from a given phenotype.
However, these days, the central dogma has broken down - with the
advent of genetic engineering. These days, if a woman likes to dye her
hair red, she can engineer a red-hair gene into her kids - if she
wants to - by genetic manipulation.
In the case of cultural evolution, intelligent agents can analyse how
a genotype results in a phenotype. With such knowledge they are able
to turn modifications of the phenotype into changes in the genotype.
For example, if it is found that people prefer cakes if they are
chopped into smaller pieces, then the recipe can be changed so that
smaller cake tins are used.
We are not ignorant about how Lamarckian inheritance works in
cultural evolution. On the contrary, we can see, in considerable
detail, exactly how it works.
Genes have a physical substrate: whereas memes don't exist -
except in people's minds
Memes do have a physical substrate. Any pattern of information must
have some material instantiation. However, information can be stored
in any physical medium. This is also true of genes. Genes exist in
databases today - as well as being instantiated in coils of DNA.
Here is Daniel Dennett on the issue:
[Footage of Daniel Dennett]
The influence of design on ideas obliterates any inherited variation
The QWERTY keyboard is a good example of the power of inheritance.
If you ask multiple teams to solve the problem of designing a keyboard
from scratch, each will produce a different key layout.
Similarly with the NATO
phonetic alphabet: Alpha, Bravo, Charlie, Delta - and so on. There
are many other possible phonetic alphabets - the details of the one we
have are the result of numerous random choices.
In very many cases, there exist both random influences and a
historical tradition. So: the influence of inheritance is
Culturally-transmitted behaviours are not copied, they are
reconstructed from observed behaviours
This is Eva Jablonka's primary objection to memetics - as expressed in
Evolution in Four Dimensions. It seems to me to be a
misunderstanding about what it means to copy something.
For example, Jablonka insists that to qualify as memetic transmission,
copying should be "development-independent and learning-independent".
Why these conditions are imposed is not clear to me. However,
Jablonka's position is often lumped with that of Dan Sperber - which
we will come to next.
The existence of predispositons to ideas shows that there
is something other than copying going on
For memetics to be a reasonable research programme, it
should be the case that copying, and differential success in causing
the multiplication of copies, overwhelmingly plays the major role in
shaping all or at least most of the contents of culture. Evolved
domain-specific psychological dispositions, if there are any, should
be at most a relatively minor factor that could be considered part of
That seems like a false dichotomy:
In fact, psychological dispositions are one of the mechanisms
by which differential success of memes is produced.
Also, why is the possible role of mutations being neglected in Dan's
characature of memetics? Selection is only half of evolution
- the other half is the processes that generate variation. Selection
can only choose between variants that are actually presented.
Memeticists have to give empirical evidence to support
the claim that, in the micro-processes of cultural transmission,
elements of culture inherit all or nearly all their relevant
properties from other elements of culture that they replicate.
Now, exact and complete copying is quite common - e.g. if you are
copying a passage of text. However Sperber wants to emphasize the
cases where it does not happen. For example, where you laugh
at the end of a joke to alert your audience to the fact that the
punchline has been reached, and a hearer of that joke retells it, but
adds their own laugh - rather than producing a detailed copy of
Memetics is concerned with what is inherited via copying. In the case
of this example, what is copied is the idea of a laugh -
rather than the details of all the ha-has and ho-hos. Things that are
not copied, are not inherited, and do not go on to play a role in any
resulting evolutionary process. That doesn't mean that they don't
exist, or aren't important - just that their details do not persist as
part of cultural inheritance.
Similarly in genetic evolution, hairstyles are not passed on via DNA.
That doesn't mean that they don't exist, or that they aren't important
aspects of the phenotype. That genetics doesn't explain hairstyles
does not invalidate genetics. Similarly that imitation doesn't explain
the detailed ha-ha and ho-ho of a laugh does not invalidate
Sperber's claim about what memeticists have to demonstrate is based
on his own straw man version of memetics - as far as I can tell.
Here ends my list of memetic misunderstandings. Enjoy!