Darwin's visit to the Galapagos islands let him see the tracks of evolution. His visit alllowed him to observe how migrants from the mainland had been systematically deformed by their island lifestyle - and also how nearby islands were occupied by subtly different types of creature. This created a natural laboratory, filled with the results of natural experiments in evolution.
Such a natural laboratory is not so critical for cultural evolution - since we
can easily see that going on in real time. However, fortunately, we do
have some natural laboratories, and they do provide some interesting data.
Memes get isolated on islands in much the same way as genes do. Perhaps the
greatest natural experiments in island cultural isolation took place in
Australia and Japan. Both were colonised by humans many tens of thousands of
years ago. Australia's culture developed slowly, and has subsequently been
rather messed up by European settlers - but in Japan much of the original
culture has survived and thrived.
I figure this makes Japan the Galapagos of memetics. A map illustrates the
extent of its isolation from the mainland of China and Korea. Far enough to
reduce meme flow to a trickle.
Japanese culture is rich, old and contains many interesting and well-known
features. Many of these are related to the culture of nearby mainland China -
but often there are interesting differences. Japan has its own martial arts,
sports, religions, games, cuisine, architecture, traditions and ceremonies.
In the organic realm, islands are mostly evolutionary dead ends. They are eventually invaded by predators and more effective creatures from the mainland, who wipe them out. However, they also sometimes act as evolutionary incubators and sources of innovation and new species. In Japan I think we can see the cultural equivalent of that. Japan is one of the rare islands where interesting cultural evolutionary innovation has happened. In this case, the results are strong and vibrant enough to persist and go on to influence what happens on the mainland.
As part of my Memetics Glossary project, I put together some lists which illustrate the parellels between memetics terminology, and terminology from biology. Here are the lists:
A few things are worth noting here. There are quite a few terms from genetic that have direct parallels in memetics - and which are based on the gene-meme parallel.
I think this helps to illustrate the value of the parallel. It also illustrates some of what you are missing if you don't use the meme terminology.
One of the other points of the exercise - from my perspective - was to identify some of the less regular terminology, so decisions can be made about what to do with it.
From the "Irregular terms" section - we have "Memeplex" - but there is no "Geneplex" - but there should be!
"Meme shedding" refers to the liberal shedding by hosts of copies
of their memes into their environment.
The term was named by analogy with virus shedding - which
refers the way infected hosts often liberally shed viruses they are infected
with into their environment - so that they can go on to infect others.
Meme shedding is a very commonly-used advertising technique. Using logos on
products result in meme-shedding. Display advertising works using meme
shedding. For many memes, public display in a populated area is sufficient to
create copies of the meme in the minds of many people.
The internet now allows meme shedding to take place on a global scale - and it
is now possible for one individual to infect millions of others with their memes.
Much meme shedding takes place using visual media - but there is also audio meme shedding. Here is a video illustrating some attempted religious meme-shedding:
What would a human being without culture look like?
Of course this is the "forbidden experiment" - but nature has performed some
natural experiments in the area - and produced what are known as
"feral children".
Typically feral children are unable to speak - or walk upright. This
illustrates how an upright posture is still a culturally transmitted trait -
even among modern humans.
A creative work that is ripe for creating derivitives from is often referred to as being an exploitable.
Next, some examples to illustrate these concepts:
Parody
Original
Parody
The Tipping Point
The Tipping Pot
Born this way
Perform this way
Cover versions
Original
Cover version
Bohemian Rhapsody (Queen)
Bohemian Rhapsody (The muppets)
Paparazzi (Lady Gaga)
Paparazzi (Greyson Chance)
Exploitables
Exploitable
Exploit
Sunny D and Rum
Sunny D and Rum song
Mashups
Stayin' Alive In The Wall (Pink Floyd vs Bee Gees)
Well, in our country," said Alice, still panting a little, "you'd generally get to somewhere else — if you run very fast for a long time, as we've been doing."
"A slow sort of country!" said the Queen. "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!"
The Red Queen Hypothesis refers to the way in which adaptation is constantly needed in order for the individuals of a species to maintain their fitness - in the face of constantly and rapidly evolving parasites. It invokes an evolutionary arms race between hosts and parasites. The short generation time of the parasites results in rapid evolution for them. This pushes the hosts around in gene-space, in order to avoid the attentions of the parasites.
The parasites are undesirable from the perspective of individual hosts - but they can have some overall positive effects. They constantly deform the fitness landscape of their hosts, keeping the hosts constantly off balance. This can result in previously separated peaks in the fitness landscape of the hosts sometimes turning into a ridge system - creating paths that lead away from what would otherwise have been sub-optimal adaptive peaks, and promoting evolutionary change.
Bill Hamilton promoted the idea that this Red Queen race helped hosts to invent sexual recombination - so they would be better able to defend themselves against the attention of parasites by maintaining a large quantity of genetic variation in their populations - thereby making life for parasites more challenging.
Sexual recombination is one of nature's masterpieces, and it seems likely that we have a Red Queen race to blame for it.
These days, a second Red Queen race is taking place. This time around, thee rapidly-reproducing symbionts are not bacteria and viruses, but memes - swarming in our heads and infesting our computer networks. As with the organic Red Queen race some of the symbionts are parasites which the hosts want to avoid. As before short generation time of memes and their rapid evolution pushes their hosts around in gene-space, keeping them constantly off balance, and accelerating genetic change in their gene pool.
The first Red Queen race may have led to the triumphant development of sexual recombination. What new techniques might the hosts use to defend themselves against exploitation in this second Red Queen race?
Will they use genetic engineering? A global hospital? Will meme therapy subdue the bad memes with good memes?
Or perhaps the memes will be triumphant. Meme warfare may mean that the most agressive memes are among those that rise to power. Parasites often evolve into relatively stable relationships with their hosts - but sometimes they wipe them out. That outcome becomes more likely when the parasites have multiple host species, and are not so dependant for their survival on the continuing welfare of any one of them.
At the moment, memes are pretty dependent on humans, but once our computer systems become sufficiently advanced, the memes seem likely to swarm out of the human heads and onto the new digital systems with considerable enthusiasm.
After they have estabished themselves fully in a digital medium, the memes may not need the humans quite so much. They will have multiple host species, and will not be so dependent on any one of them.
We will need to have a good and clear understanding of the dynamics of these types of coevolving systems to have the best chance of surviving our coming encounter with this type of situation.
For more details, about these kinds of possibility, please read my Memetics book - when it comes out in a few months time. It's going to look like this: [holds up book]
The movie is called "The Chronicles of Rick Roll". It looks set to star quite a few popualar internet meme personalities. Here's the trailer:
Meme talent slated to appear in the movie include: Antoine Dodson (Hide Yo’ Kids), Bear Vasquez (Double Rainbow), Ben Schulz (Leeroy Jenkins), Brian Collins (Boom Goes the Dynamite), Stephen Quire (Freakout Kid), Gary Brolsma (Numa Numa), Mark Hicks (Afro Ninja), Catie Wayne (Boxxy), Matt Sloan & Aaron Yonda (Chad Vader), Tay Zonday (Chocolate Rain), Michael Copper (Copper Cab), David DeVore (David After Dentist), Judson Laipply (Evolution of Dance), and Ted Williams (Man with the Golden Voice).
Hi! I'm Tim Tyler, and this is a video about memes and the evolution of human ultrasociality.
Humans are ultrasocial creatures. They live in large cities and and often congregate in huge numbers at social events of various kinds. Humans do not normally bristle with hostility on encountering other humans - and indeed are likely to engage in cooperative behaviour - even with strangers. Memetics offers an interesting explanation of human cooperation and ultrasociality.
The idea is that meme reproduction depends on social contact between humans. Increased levels of social contact between their hosts are good for memes since this results in more reproductive opportunities for them. Memes that promote human ultrasociality have the effect of pushing humans into close proximity with each other, so the memes can infect new hosts. All the memes in the host benefit from this - including the ultrasociality memes.
Ultrasocial humans collect more memes than less sociable humans. Since memes are - on average - beneficial, memes promoting ultrasociality can have the effect of increasing the genetic fitness of their human hosts - by allowing them to collect more memes. So, the hosts are typically eager to embrace ultrasociality-producing memes - and would eventually evolve some degree of ultrasociality anyway in meme-rich evironments. Over time the ultrasociality trait gradually begins to migrate into their germ line, via the classical process of genetic assimilation, so that learning it slowly becomes easier.
Memeplexes also tend to favour the incorporation of ultrasociality memes into them. Ultrasociality memes offer a double fitness boost to memes they have memetic linkage with. The first boost is due to being linked to the fit ultrasociality memes and the second boost due to being more likely to be spread around by the ultrasocial hosts of the ultrasocial memes. Memes in memeplexes are thus likely to welcome ultrasociality memes into the fold.
Large-scale group behaviour is a key component of many religions. In masses, a large mass of humans congregates and engages in a festival of meme exchange. Church services are regular mini-masses. Since memes are stored in fallible human memory and benefit from frequent rehearsal, the meme repetition that takes place at masses and church congregations is also beneficial to them. While such religious ceremonies may offer benefits to the humans that engage in them, they seem to be orchestrated by memes, and it is probably mostly the memes that benefit from them. Religions also promote social behaviour in another way - by actively promoting prosletysing. This essentially involves approaching strangers and attempting to spread your memes to them, and bring them into the flock. This is a particularly-blatant attempt by the memes to use host resources to further their own reproductive ends by infecting new hosts. An understanding of how memes cause humans to form masses and congregations - and to engage in prosletysing - looks as though it will form a important part of a naturalistic theory of religion.
As far as I know, links between memes and human sociality and cooperation were first proposed by Donald T. Campbell in a 1983 article titled "The two distinct routes beyond kin selection to ultrasociality". The theme was taken up by Francis Heylighen in 1992 and expanded on by him over the years. However, neither author really got the idea described here. The idea was eventually clearly spelled out and popularised by Susan Blackmore in a 1997 article titled "The Power of the Meme Meme" - and she has two whole chapters about memetic theories of altruism in her 1999 memetics book.
Recently, the idea that memetic evolution drove the evolution of human ultrasociality been the subject of much experimental work, and several books - by Herbert Gintis, Peter Richerson, Robert Boyd, Joseph Henrich and others.
While there is now a consensus that meme-gene coevolution is primarily responsible for human ultrasociality, alas, many of the academic researchers have ignored the simple and beautiful memetic hypothesis given here - and have instead adopted what appears to be a highly implausible model based on group selection. As an illustration of this neglect, in a 2000 review of why humans cooperate - by Boyd and Richerson - there is a broad review of classes of hypotheses that have been proposed to account for the phenomenon - and the memetics-based hypotheses described here doesn't even get mentioned.
The memetic explanation given here does not claim to be responsible for all prosocial behaviour. The standard evolutionary accounts of prosocial behaviour attribute it to kin selection, reciprocal altruism, virtue signalling, cooperating to perform demanding tasks and mating behaviour. Some other hypotheses also help explain human cooperation. Humans sometime manipulate other humans into cooperating. For example, this is done with the "fake" kin groups created by military uniforms and school uniforms which are used to encourage cooperation based on percieved relatedess. Also, humans may sometimes overgeneralise the moral that it pays to be nice to others - and behave in an irrationally nice manner. This effect could be magnified in the unusual modern ecosystems in which humans find themselves - where they meet large numbers of people who are not really members of their tribe. However, the memetic explanation appears to apply to most of the cases in which humans cooperate where chimpanzees do not.
The memetic explanation of human ultrasociality should be one of the triumphs of the field. At the moment, I think it is fair to say that it is not widely recognised or understood. That plainly needs to change. There is more about memes and human ultrasociality in my book on memetics, which is now available.
Lastly, here is Daniel Dennet, lecturing on the topic:
Campbell, Donald T. (1983) The two distinct routes beyond kin selection to ultrasociality: Implications for the Humanities and Social Sciences. In: The Nature of Prosocial Development: Theories and Strategies D. Bridgeman (ed.), pp. 11-39, Academic Press, New York.
Richerson, P. J. and Boyd, R. (1998) The Evolution of Human Ultra-sociality, I. Eibl-Eibesfeldt and F. K. Salter (eds.), Indoctrinability, Ideology and Warfare. New York: Berghahn Books. Pp. 71-96.
Richerson, P. J. and Boyd, R. (2005) Solving the puzzle of human cooperation. In Evolution and Culture, edited by S. Levinson and P. Jaisson. MIT Press, Cambridge MA, pp. 105-132.
Blackmore is a parapsychologist who rejects the paranormal, a skeptical investigator of near-death experiences, and a practitioner of Zen. Her explanation of the science of the meme (memetics) is rigorously Darwinian. Because she is a careful thinker (though by no means dull or conventional), the reader ends up with a good idea of what memetics explains well and what it doesn't, and with many ideas about how it can be tested - the very hallmark of an excellent science book.
Why do humans, uniquely among animals, cooperate in large numbers to advance projects for the common good? Contrary to the conventional wisdom in biology and economics, this generous and civic-minded behavior is widespread and cannot be explained simply by far-sighted self-interest or a desire to help close genealogical kin. In A Cooperative Species, Samuel Bowles and Herbert Gintis--pioneers in the new experimental and evolutionary science of human behavior--show that the central issue is not why selfish people act generously, but instead how genetic and cultural evolution has produced a species in which substantial numbers make sacrifices to uphold ethical norms and to help even total strangers.
Cooperation among humans is one of the keys to our great evolutionary success. Natalie and Joseph Henrich examine this phenomena with a unique fusion of theoretical work on the evolution of cooperation, ethnographic descriptions of social behavior, and a range of other experimental results. Their experimental and ethnographic data come from a small, insular group of middle-class Iraqi Christians called Chaldeans, living in metro Detroit, whom the Henrichs use as an example to show how kinship relations, ethnicity, and culturally transmitted traditions provide the key to explaining the evolution of cooperation over multiple generations.
Moral Sentiments and Material Interests presents an innovative synthesis of research in different disciplines to argue that cooperation stems not from the stereotypical selfish agent acting out of disguised self-interest but from the presence of 'strong reciprocators' in a social group.Presenting an overview of research in economics, anthropology, evolutionary and human biology, social psychology, and sociology, the book deals with both the theoretical foundations and the policy implications of this explanation for cooperation. Chapter authors in the remaining parts of the book discuss the behavioral ecology of cooperation in humans and nonhuman primates, modeling and testing strong reciprocity in economic scenarios, and reciprocity and social policy. The evidence for strong reciprocity in the book includes experiments using the famous Ultimatum Game (in which two players must agree on how to split a certain amount of money or they both get nothing.)
This path-breaking book addresses the nature of human sociality. By bringing together experimental and ethnographic data from fifteen different tribal societies, the contributors are able to explore the universality of human motives in economic decision-making, and the importance of social, institutional and cultural factors, in a manner that has been extremely rare in the social sciences. Its findings have far-reaching implications across the social sciences.
In Unto Others, philosopher Elliott Sober and biologist David Sloan Wilson bravely attempt to reconcile altruism, both evolutionary and psychological, with the scientific discoveries that seem to portray nature as red in tooth and claw. The first half of the book deals with the evolutionary objection to altruism. For altruistic behavior to be produced by natural selection, it must be possible for natural selection to act on groups - but conventional wisdom holds that group selection was conclusively debunked by George Williams in Adaptation and Natural Selection. Sober and Wilson nevertheless defend group selection, instructively reviewing the arguments against it and citing important work that relies on it. They then discuss group selection in human evolution, testing their conclusions against the anthropological literature.
Herbert Gintis has been doing a lot of work on cultural evolution in the past decade. His work on cultural evolution is mostly oriented around the issue of why humans cooperate with each other to the extent that they do - why humans are ultrasocial. Here are some related resources:
Why do humans, uniquely among animals, cooperate in large numbers to advance projects for the common good? Contrary to the conventional wisdom in biology and economics, this generous and civic-minded behavior is widespread and cannot be explained simply by far-sighted self-interest or a desire to help close genealogical kin. In A Cooperative Species, Samuel Bowles and Herbert Gintis--pioneers in the new experimental and evolutionary science of human behavior--show that the central issue is not why selfish people act generously, but instead how genetic and cultural evolution has produced a species in which substantial numbers make sacrifices to uphold ethical norms and to help even total strangers.
Moral Sentiments and Material Interests presents an innovative synthesis of research in different disciplines to argue that cooperation stems not from the stereotypical selfish agent acting out of disguised self-interest but from the presence of 'strong reciprocators' in a social group.Presenting an overview of research in economics, anthropology, evolutionary and human biology, social psychology, and sociology, the book deals with both the theoretical foundations and the policy implications of this explanation for cooperation. Chapter authors in the remaining parts of the book discuss the behavioral ecology of cooperation in humans and nonhuman primates, modeling and testing strong reciprocity in economic scenarios, and reciprocity and social policy. The evidence for strong reciprocity in the book includes experiments using the famous Ultimatum Game (in which two players must agree on how to split a certain amount of money or they both get nothing.)
This path-breaking book addresses the nature of human sociality. By bringing together experimental and ethnographic data from fifteen different tribal societies, the contributors are able to explore the universality of human motives in economic decision-making, and the importance of social, institutional and cultural factors, in a manner that has been extremely rare in the social sciences. Its findings have far-reaching implications across the social sciences.
I think the meme concept is a loser because it is too detached from the gene concept to render a mimetic analysis evolutionarily coherent. The correct theory is that of gene-culture coevolution, as developed by several authors, including Cavalli-Sforza and Feldman.
They even manage to treat memetics seriously, despite the fact that memetics' attempt to detach culture from reproduction, production, cooperation, conflict, and the other basic activities of social life cannot possibly succeed.
I think the answer to Stanovich's problem is that the whole notion of memetics is rubbish. His defense of the notion in the book is uncharacteristically weak, to the point of being pathetic. For instance, he asserts that memetics itself is a meme complex, so if many people accept memetics and memetics is wrong, the memetics must be right! In fact, memetics posits behavior with no evolutionary justification. This is: we accept memes because they force themselves upon us. But, a creature who behaved in this way would be evolutionarily eclipsed by another who did not succumb.
The advert used fear of the end of the world to promote the
presidential campaign of Lyndon Johnson. Johnson won a landslide victory - and
the advert made marketing history - for its controversial use of fear as an
incentive.
You can watch the Daisy Ad here:
Religions make use of fear as a motivator by threatening helfire and damnation. Chain letters use the same trick - by threatening unspecified bad luck if you break the chain. However, the use of fear in a political marketing campaign seems rather underhand.
These days, some derivative adverts have appeared. Here we will present a few
of them - and consider how they fit into the terminological framework of
memetics. The first one is probably the best one.
These adverts use a kind of
memetic hitchhiking on the original advert, via its title.
They exhibit memetic linkage to the original ad - in the namespace of video titles.
They use search magnet techniques to show up in searches for the original advert.
Environmental inheritance refers to inheritance via the environment. It includes cultural evolution - but also other types of heritable environmental influences.
If I give my son a big suitcase full of gold bars when I die, few would claim this is a case of cultural inheritance. Yet it is pretty clearly a form of inheritance.
The Big Three
Environmental inheritance is the third of the "Big Three" inheritance channels available to natural systems:
Organic inheritance;
Cultural inheritance;
Environmental inheritance;
Diagram
Representing these forms of inheritance as a diagram, it looks something like this:
Here you will see that cultural inheritance is represented as a subset of environmental inheritace. This is because all culture must currently necessarily be represented "in the environment" at some point during its transmission down the generations.
Significance
Non-cultural environmental inheritance is pretty important. It typically includes your place on the planet, the ecosystem you are born into, and a bunch of non-cultural resources that result from modification of the environment by your ancestors.
Xemes and Xemetics
If memes are defined as only transmitting culturally-inherited information, it would be nice to have another term for environmental inheritance. I propose Xemes (based on eXternal transmission). Xemetics could be the science of Xemes. Xemes is pronounced rather like "Zemes" - NOT "eX-emes".
Implications for Dual Inheritance Theory
Non-cultural environmental inheritance is one of the big things that is wrong with Dual Inheritance Theory.
IMHO, non-cultural environmental inheritance is big enough and important enough to make Dual Inheritance Theory seem as though it has a very silly name.
Videos
John Odling-Smee - Construction Dynamics Seminar Series - Niche Construction and Niche Inheritance.
"Epigenetic" is a word that has been sabotaged recently by some biologists.
Conrad Waddington is usually credited with coining the term "epigenetics" - in 1942 - meaning:
The branch of biology which studies the causal interactions between genes and their products, which bring the phenotype into being.
I think this usage is fine.
However, these days, the term "epigenetic" has been hijacked by a bunch of ignorant biologists who think it should mean this:
Epigenetics is the study of heritable changes in phenotype caused by mechanisms other than changes in the underlying DNA sequence.
I think this usage is absolutely awful.
Definition of the words "gene" or "genetic" that specify nucleic acids seem terrible to me. Genetics is - or should be - the basic science of heredity in biology. If we make creatures with non-nucleic-acid inheritance media, or find creatures with non-nucleic-acid inheritance, or consider our distant non-nucleic-acid-based ancestors, we really do not want to have to redefine the basic terms of genetics to be able to discuss how they inherit things. This is a problem we should be smart enough to be able to see coming.
So: please boycott the "new" epigenetics. It hijacks a perfectly acceptable piece of terminology, and turns it into an awful stinking mess.
If anyone ever starts talking to you about "epigenetic inheritance", well, please refer them to this page.
One way of modelling human culture is as an extension of human biology. If you do that then one way of modelling cultural information is as part of a human extended genotype. The products of culture would then be modelled as being part of the phenotype of that extended genotype. This type of model is, alas, common in academic studies of cultural evolution. As Mesoudi (2011) puts it:
In a typical cultural evolution model, a population is assumed to be composed of a set of individuals, each of whom posseses a particular set of cultural traits. A set of microevolutionary processes is specified that changes the variation of those traits over time.
An "extended genotype" would make reasonable sense as a model if culture was only transmitted vertically. However, in fact only a few traits are only transmitted vertically. If you introduce "oblique" and "horizontal" transmission the result is more like multiple genotypes than a single genotype - and the "microevolutionary processes" involved can get complicated.
Using this type of model, you can approximately reproduce the same dynamics that are actually exhibited by cultural evolution - if you are prepared to model sufficiently complex micro-evolutionary transmission processes. However, this type of model is philosophically unsatisfactory. As with symbiotic gut bacteria and foodstuffs, it is best to just classify cultural entities as belonging to different species. They have their own lifecycles and inheritance mechanisms and interests. They usually spend some of their lifecycle outside the human body, where they may be destroyed or copied. Modelling them as extensions of the human genotype runs contrary to Occam's razor and makes no sense at all. It leads to byzantine models, which are specific to cultural evolution processes. The correct approach is to use the existing perfectly conventional models of symbiosis. That is the approach taken by memetics.
The extended genotype is sometimes codified in the form of the phenogenotype - as in this 1992 paper.
Durham uses the term 'meme' for a unit of cultural inheritance. I think his defense of this is one of the strongest points in this great book. He shows that culture cannot be identified with phenotype or behavior. It follows that we must drop the term 'geno-phenotype'. In its place we can use the term 'geno-memotype.'
Phenogenotypes were an awful messed-up concept - but in memetics, there is no 'geno-memotype' to replace it. That is pretty-much an unnecessary concept. Instead there is symbiosis.
Evan Louis Sheehan has a nice way of explaining the problem with "extended genotype" models in his book: The Laughing Genes. He says:
Perhaps the ideas that aided in early human survival should be considered as some sorts of extensions to the genes. Then, just as good genes yielded good biological attributes such as strong muscles, good ideas yielded good extensions to biology in the form of such things as clubs and spears. Indeed, this is the way I used to think of cultural ideas, as extensions to the genes that underwent evolutionary development in parallel to the genes. Ideas that provided survival advantage were passed down vertically from generation to generation, and persisted simply because they provided survival advantage, just as some genetically inspired valuable traits, such as keen eyesight or strong muscles might do. I now see this as an incomplete picture of the ways that ideas are able to evolve. I must thank Dawkins once again for the revelation that allowed me to see this.
The most comprehensive treatment of this academic folly is probably
Ben Cullen's book: Contagious Ideas: On Evolution, Culture, Archaeology and Cultural Virus Theory. He calls the idea by the term "inclusive phenotype" - since the academic researchers involved bundle cultural and genetic influences into one human phenotype - in what Ben refers to as a "bio-cultural muddle".
Susan Blackmore pioneered the hypothesis that the human big brain is actually an adaptation for storing large quantities of memes. She has a whole chapter (called "The big brain") on this hypothesis in her 1999 book The Meme Machine.
The basic idea
The idea that the enlarged human cranium might be an adaptation for housing our mutualist symbiont visitors is an astonishing and counter-intuitive one. However, culture and co-evolution with culture has resulted in most of the main ways in which we differ from chimpanzees. It really makes a lot of sense for our large brain to be an adaptation to human culture.
Other ideas
To see how plausible the idea is, one has to consider its merits relative to other theories that purport to explain the same observations:
Probably the leading theory is the Machiavellian intelligence hypothesis - also known as The Social Brain Hypothesis. This states that humans became as smart as they did as a result of an arms race involving social skills - lying, cheating, manipulation - and the detection of these things in others.
There is also the idea that sexual selection was involved. That some aspect of being smart was sexy - and that selection by members of the opposite sex (probably mostly females) resulted in large brains being favoured. This makes the brain the human equivalent of a peacock tail. This idea - along with the Machiavellian intelligence hypothesis - is discussed at length in a fine book: The Runaway Brain.
Another idea is that neoteny was responsible. Young infants have disproportionately large heads compared to adult forms. Human evolution features neoteny. So, our large heads could be a side effect of neoteny.
Another idea is that our large craniums resulted from the tendency toward bipedality in our species. Bipedality, in turn, forced a narrowing of the pelvic region making it more difficult for females to give birth. Selection would have then favoured females who gave birth to premature, less developed, and, therefore, smaller infants. Being born premature allows human babies to come into the world while their brains are still developing. Human brains continue to grow at rapid, fetal rates after birth - allowing a greater eventual size to be attained. This hypothesis is covered in Lynch and Granger (2008).
Another idea is that omega-3 fats represented a nutritional constraint that got lifted by dietary changes. That hypothesis is laid out in the book The Driving Force.
Early hypotheses suggested that environmental challenges and tool use drove the evolution of big brains. Such ideas have now mostly been superseded by more social hypotheses.
Many of these ideas are not mutually exclusive. It is possible that each of them contributed something to the enlargement of the human brain. However, it also seems likely that some of these hypotheses are more important than other ones.
The place of the meme hypothesis
The idea that our big brains are meme nests is broadly compatible with the idea that runaway sexual selection is responsible. It suggests a sexually-selected arms race where what was sexy was a good sense of humour, being able to sing love songs, the ability to dance the latest dance - and other products of cultural evolution.
The Machiavellian intelligence hypothesis no doubt has some truth to it as well. It doesn't really explain why our brains blew up, while chimpanzee brains did not. What humans have that chimpanzees mostly don't is language and culture.
Cost
The cost of a large brain in enormous. Brains must be providing a huge benefit to allow them to pay for themselves in the way that they did among our ancestors. Since the effects of culture are enormous, the meme theory shows promising signs of being able to account for the magnitude of the observed benefits.
Timing
The oldest archaeological sites containing tools are dated to 2.6-2.55 million years ago - around the beginning of the stone age - which is an excellent match for when the human brain first really started to inflate. Timing considerations provide significant support to the meme theory.
Domatia
Since memes are typically beneficial cultural symbionts, cranial meme nests are a lot like ant domatia. My pages on domatia videos and domatia corridors have more information about this.
Testing
Of course, to qualify as being genuine science, hypotheses need to be testable, and one obvious weakness of these ideas is they they relate to events millions of years ago - and so are not trivial to test. I won't go into the experimental possibilities here - except to say that there are some. Both skulls and some aspects of culture fossilize. We will probably have access to enough evidence on the issue to get to the bottom of it in due course.
For the moment, I just want to point at this hypothesis, and make some noise to help draw people's attention to it. It is one of the more radical proposals of meme theory, one that has a good chance of being correct, and one that has so far received very little attention.
Some of Sue's other proposals - for example, the origins of human ultrasociality - have been showing good signs of panning out in recent years. The "big brain" hypothesis she pioneered is also deserving of attention.
Rendell, Luke, Fogarty, Laurel, Laland, Kevin N. (2011) Runaway cultural niche construction. Philosophical Transactions of the Royal Society of London - Series B: Biological Sciences.
We can be pretty sure that memes were adaptive among our ancestors since we
have meme-spreading adaptations - our incessant babbling, our ultrasociality
and the huge meme libraries we carry around everywhere on our shoulders.
It seems likely that memes are adaptive today - at least up to a point - since
meme-free humans are like primitive cave men, and most such creatures would not do very well in the modern world.
However, neither of these sets of observations really explains the reasons why memes are adaptive.
Part of the explanation probably seems obvious. Memes allow individuals to:
Reduce the costly errors associated with trial and error learning;
Acquire useful ideas much more quickly than trial and error would permit;
Acquire better quality ideas than they would have been likely to produce themselves;
Boyd and Richerson have looked into the issue of why culture is adaptive -
presenting their results in Richerson and Boyd (1995) and their 2005 book on
the topic, Not by Genes Alone.
They give more-or-less the above analysis. However, in Not by Genes
Alone (2005, p.127) they then go on to give what they themselves describe
as a just-so story about the circumstances under which culture is adaptive.
The title of their section on the topic is: "Culture is adaptive because it
provides information about variable environments". It argues that memes are
adaptive because they allow humans to adapt better to local conditions. They
give plenty of examples over four pages. It is certainly true that culture
helps humans to adapt to local environments. However, the whole theme is really a
misleading and inaccurate one.
The reason memes are adaptive is because they let you obtain good quality
ideas quickly, and at low cost. Some of those ideas are no-doubt
contain information about how to adapt to local environments. However, others
are more universal. For example, fire, love songs, levers and hammers are useful in a wide range of conditions and environments.
Why transmit these ideas culturally, rather than wiring them into the genome,
then? The answer is essentially because the genome is full, and can't really
accomodate all the universal cultural knowledge. Even if evoultion could
somehow find a way to wire a fire-starting instinct into the genome, the results
would not be much better than transmitting the knowledge by cultural
means. So, this is a challenging task for evolution with a pretty minimal
payoff.
So, my council is to forget about the benefit of memes being enhancing the ability to adapt to local environments. The bottom line is that memes benefit people by allowing them to obtain lots of good quality ideas quickly, and at low personal cost.
Darwin's visit to the Galapagos islands let him see the tracks of evolution. His visit alllowed him to observe how migrants from the mainland had been systematically deformed by their island lifestyle - and also how nearby islands were occupied by subtly different types of creature. This created a natural laboratory, filled with the results of natural experiments in evolution.
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The video doesn't really get on to the topic of memes until fairly near the end.
Environmental inheritance refers to inheritance via the environment. It includes cultural evolution - but also other types of heritable environmental influences.
"Epigenetic" is a word that has been sabotaged recently by some biologists.
One way of modelling human culture is as an extension of human biology. If you do that then one way of modelling cultural information is as part of a human extended genotype. The products of culture would then be modelled as being part of the phenotype of that extended genotype. This type of model is, alas, common in academic studies of cultural evolution. As Mesoudi (2011) puts it:
Susan Blackmore pioneered the hypothesis that the human big brain is actually an adaptation for storing large quantities of memes. She has a whole chapter (called "The big brain") on this hypothesis in her 1999 book The Meme Machine. 
We can be pretty sure that memes were adaptive among our ancestors since we
have meme-spreading adaptations - our incessant babbling, our ultrasociality
and the huge meme libraries we carry around everywhere on our shoulders.