Thursday, 28 August 2014

Meme liberation and the modern cranial shrinkage

The general trend in brain size among our immediate ancestors over the last three million years has been upwards, as this graph illustrates:

However, recently, there are some signs that this trend has abated. In particular Neanderthals had larger brains than modern humans.

Is this consistent with the idea that big brains are meme nests? Surely memes have been on the up-and-up - while brain size has not.

The modern brain shrinkage corresponds to the rise of modern agriculture and increased population densities. Here's a quote from a 2010 article on the topic:

Bailey and Geary found population density did indeed track closely with brain size, but in a surprising way. When population numbers were low, as was the case for most of our evolution, the cranium kept getting bigger. But as population went from sparse to dense in a given area, cranial size declined, highlighted by a sudden 3 to 4 percent drop in EQ starting around 15,000 to 10,000 years ago. “We saw that trend in Europe, China, Africa, Malaysia—everywhere we looked,” Geary says.

Through most of human history the meme pool had to fit in a single brain. There wasn't much in the way of specialization - all the tribe members played similar roles (except perhaps for the doctor). There was probably some gender-based specialization, but that was about it - the meme pool mostly had to fit in a single mind.

With the advent of agriculture, large populations and exchange and specialization - and more advanced language - all this radically changed. Memes were liberated from the confines of a single mind, and the meme pool was able to expand enormously. Towns could support far more memes that any hunter-gatherer tribe could manage. The process of meme liberation eventually led to writing - another major move to liberate memes from the human skull.

The meme pool not being effectively confined to a single mind would have massively reduced the selection pressure on minds to grow to accommodate more memes. Now minds only had to accommodate the memes associated with a given specialization.

Other theories may have something going for them too. Modern humans have been domesticated by their institutions - and domestication often results in smaller brains - since the domesticated creatures have their defensive and foraging needs supplied for them. Also agriculture led to poorer diet - and that might have had a negative effect on brain size too (though re-feeding modern humans doesn't give them much bigger brains).

However, the idea of big brains as meme nests is at least consistent with the modern cerebral downturn. The modern cranial shrinkage corresponds to the liberation of the meme pool from the mind of a single hunter-gatherer mind. The division of labor that came with large populations would have meant that each specialization had its own, much smaller and largely-independent meme pool. The pressure on the brain to grow to accommodate the entire meme pool of the human race was off - and stupider humans could thrive.

The liberation of memes led to a removal of the size limit on cumulative cultural evolution. Now that they were no longer effectively confined to a single mind, the modern meme explosion began to gather speed.


Wednesday, 27 August 2014

Walking made us human

Walking was part of our lineage from the point where it split from chimpanzees - as far as archaeologists can tell.

The idea that walking made us human probably seems naive these days. However, tools, fire and language followed much much later - and the significance of walking gets quite a shot in the arm from memetics.

As I explain in considerable detail in my 2011 memetics book, walking was one of the earliest socially transmitted traits in our ancestors. The need to walk put pressure on infants to master the social skills needed to learn to walk from their parents and caregivers.

Chimpanzees socially transmit use of tools such as hammers. However, there's nothing similar to walking in demanding early learning and so profoundly affecting development.

It was walking that kicked the race to develop social learning into a high gear in infants among our early ancestors. There was cultural transmission before walking - but is wasn't so profoundly life-changing. It is true that the expansion of the human cranium corresponding to colonization by memes didn't begin for another three million years - but that seems consistent with walking having a high significance in the development of social learning. Walking generated pressure for social learning skills to develop early. It was a while before this started having knock on effects that led to an expansion of the meme pool as the size limit on cumulative cultural evolution in our ancestors gradually began to rise.


Sunday, 24 August 2014

The curious history of meme-gene coevolution

Once serious interest in the topic of cultural evolution was rekindled in the 1970s, something very strange happened to it in academia. Most of the interested parties became obsessed with the topic of meme-gene coevolution. Retrospectively, this seems like a curious approach to exploring the subject area. I have likened it to trying to fly before you can walk. The more obvious approach is to study cultural evolution first - and then go on to study the more advanced, esoteric and difficult topic of meme-gene coevolution later.

The work I am mostly talking about resulted in four books. These ones:

  • Lumsden, C. and Wilson, Edward O. (1981) Genes, Mind, and Culture.
  • Cavalli-Sforza, L. L. & Feldman, M. W. (1981) Cultural transmission and evolution: A quantitative approach.
  • Richerson, Peter J. and Boyd, Robert (1985) Culture and the evolutionary process.
  • Durham, William H. (1991) Coevolution: Genes, Culture, and Human Diversity.

These books don't really represent a sample of the field, these were the first books on the topic and were pretty-much all of the books on the topic at the time.

In this article, I will argue that this focus on the distant past was unhealthy one, and has produced a hangover that continues to this day.

The problems with focusing on meme-gene coevolution are that:

  • The topic is difficult and demands a deep understanding of cultural evolution;
  • The distant past, is a difficult area to explore.
The problems with studying the distant past are that:

  • Evidence is difficult to obtain;
  • Experiments were challenging to perform;
  • Predictions are difficult to test.

As a double-whammy, researchers in the field appeared to all be copying each other - so the focus spread to most of the researchers involved.

Why this happened in the first place is not entirely clear. Some of the researchers involved were heavily interested in genes and genetics. For Lumsden, Wilson, Cavalli-Sforza and Feldman, the idea of a meme must have been immediately followed in their minds by questions about how this related to all the things they already knew about genes and DNA-based evolution. These were researchers who were already obsessed with ancient human history long before they developed an interest in cultural evolution. Another issue may have involved funding sources. Research would often have had to be framed in terms that administrators could understand. A fringe research area that fell between academic departments and had no established community needs to get funding somehow - and perhaps the link to human DNA-based evolution helped with funding the field. Another possibility is that if other folk in your field are studying a difficult and esoteric topic, you have to join in to keep up. Going for meme-gene coevolution suggests that you already have the topic of meme-based evolution down pat - and are ready for more advanced topics. This could have been a case of academics deliberately focusing on complex and difficult topics - for the sake of prestige.

Whatever the reasons, the early history of cultural evolution in academia largely turned into the history of meme-gene coevolution.

If instead the focus had been on memetic evolution, probably a lot more progress could have been made. To a first approximation, genes represent a static background against which cultural evolution takes place. This is because cultural evolution has such short generation times and takes place so much faster than the evolution of DNA-based human genes. This means that you can usefully study cultural evolution while ignoring the complex and difficult topic of meme-gene coevolution.

Cultural evolution is highly visible in modern times. There is an enormous wealth of data, and experiments in the field are simple and easy to perform. Furthermore, there are big practical applications on hand. Advertising and marketing have dollars to spend on discovering what things are most shared. The field of education in interested to know how best to cultivate young minds. The military wants to know how to brainwash and manipulate through propaganda - and so on and so forth.

The early, narrow focus within academia on the topic of meme-gene coevolution has had a large negative impact on the field of Darwinian cultural evolution that continues to this day. Looking at the modern literature on the topic the obsession is less intense than it once was, but still a significant factor. I wish the whole field would shake off its obsession with ancient history, and get more involved in the modern world.

We need a healthy theory of cultural evolution partly to help us guide the course of cultural evolution on the challenging oceans represented by the modern technological world. The obsession with human DNA evolution isn't helping too much with this. Culture is now moving so fast, that meme-gene coevolution is rapidly becoming an irrelevant topic. The academic experts in the field need to get off their old bandwagon and get with the program.

Saturday, 23 August 2014

Evolution can destroy design - as well as create it

Susan Blackmore has many good memes - as well as a few more dubious ones. In her recent description of her experience lecturing on memes in Oxford (recounted in A hundred walked out of my lecture), there was one of the more dubious ones. Susan said this:

I persevered, trying to put over the idea that evolution is inevitable – if you have information that is copied with variation and selection then you must get (as Dan Dennett p50 puts it) ‘Design out of chaos without the aid of mind’. It is this inevitability that I find so delightful – the evolutionary algorithm just must produce design, and once you understand that you have no need to believe or not believe in evolution.
She presented the same idea at TED. The problem with the idea is devolution. In a nutshell, whether evolution results in the accumulation or the destruction of design depends a lot on the mutation rate. In a sufficiently hostile and mutation-rich environment, living systems do not undergo cumulative adaptive evolution - instead they exhibit devolution - progressive loss of function, possibly culminating in eventual extinction. It isn't really very accurate to say that "evolutionary algorithm just must produce design". It can also destroy and extinguish all appearance of "design" - and often does so, in hostile environments.

If evolution only created design, living systems would have a rosy future. As it is, they could easily be wiped out by a stray solar mass. Evolution can destroy - as well as create.

Cultural evolution exhibits deep similarities with organic evolution

Alan Winfield recently claimed (on Twitter):

Memetics claims to resemble bio. evo. but only at the highest level of process: variation, selection and heredity.
I don't think this is true. In memetics, cultural evolution is part of biological evolution - since culture is part of biology.

Cultural evolution resembles DNA-based evolution in a wide variety of ways. There's adaptation, drift, kin selection, hitchhiking and linkage. There's parasitism, mutualism, epidemics, stasis, phenotypes, ontogeny and progress. There's Hamilton's rule, Wright's "shifting balance" theory and Fisher's fundamental theorem.

Of course, there are differences too - but the similarities are widely under-appreciated - and they run deep.

The point of memetics is to study the differences between genetics and its cultural equivalent - the study of cultural heredity. However, the very first step in that project is to appreciate the similarities with genetics - so you can make appropriate use of all the work that has already been performed.

Friday, 22 August 2014

Folk memetics

Some bits of memetics entered common usage before the 2011 online meme explosion.

Here are some examples of what we might call "folk memetics":

  • Contagion - in the dictionary the term refers to both organic and cultural influences;
  • Corporate DNA - this term has its own wikipedia page;
  • Organizational DNA - this term seems to have been coined in 1993 - it took off in 1995;
  • Man-machine symbiosis - this term dates back to the 1960s;
  • Artificial life - this dates back to the 1980s;
  • Computer virus / worm - dates back to the 1970s;
  • Earworm - Wikipedia says the term dates from the 1980s. It took of in 2009.
  • Go viral - this phrase took off in 2009;
  • Epidemics - the "obesity epidemic" and the "smoking epidemic" point towards generalized epidemiology;
Of course there are also examples of memetics-like thinking dating back to before the 1970s. For example:

Popper's popular phrase: "letting our ideas die in our stead" implies that ideas are alive - a la memetics.

Similarly August Schleicher was viewing languages as organisms back in the 1800s. Here he is in 1863:

Languages are natural organisms, which, without being determinable by the will of man, arose, grew, and developed themselves, in accordance with fixed laws, and then again grow old and die out; to them, too, belongs that succession of phenomena which is wont to be termed 'life'.
The memetics timeline offers an early history of memetics which has more examples.

Thursday, 21 August 2014

Cultural local competition

How is kin selection compatible with phenomena such as sibling rivalry and fratricide?

A big part of the answer given by scientists is local competition. By virtue of being born near to one another family members often come into competition with one another over resources - and then things can get nasty. Local competition can sometimes counteract and overcome the cooperative force associated with kin selection.

One way of avoiding local competition is to disperse offspring widely. However, this solution involves distribution costs and conflicts with trickle-feeding of offspring.

Cultural local competition is a phenomenon too. Shops face much the same dilemma that organisms do. If a parent shop fails to widely disperse offspring shops, they will compete for customers. If offspring are widely dispersed, it becomes hard to share stock, employees and training.

If there are multiple offspring organizations, they often compete with one another for resources from the parent organization(s) - the cultural version of sibling rivalry.

Offspring organizations and parent organization often share both memes and genes. Genes through things like nepotistic job offers and domesticated plants and animals - and memes through "organizational DNA" - a piece of "folk memetics" terminology. However, for most types of companies and organizations, shared memes will be a more potent force than shared genes. Cooperation between parents and offspring will be down to cultural kin selection and reciprocity - while the extent to which they compete for resources will erode that cooperation.

In defense of memes: my reply to Said Simon

Said Simon posted an article trashing memetics yesterday - titled: "Memes and Cultural Evolution". Here is my reply:

Memes are like genes - in that both transmit heritable information down the generations.

Complaining that memes split culture into little pieces is rather like complaining that bytes split computer programs into little pieces. Computer programs are full of inter-dependent components, but that doesn't mean that you can't split them into pieces. You can. It's the same with the heritable component of culture. Or anything which is composed of information. This is a property of Shannon information in information theory - and has nothing specifically to do with culture.

Genes interact during the process of their expression too. Their interactions are very complex. I sometimes wonder whether those who complain that memes divide culture into pieces have any knowledge about how genes divide organisms into pieces - and how complex ontogeny is. To me, these organic processes also look highly complex.

You can build models of meme dynamics that assume their interactions are linear - just as you can build models of genes that assume their interactions are linear - but these models should not be seen as limiting the entire domain - they don't limit the scope or applicability of the underlying concepts.

Few complain that "gene" is not useful term because genetics fails to capture the complexities of ontogeny. We have developmental biology which looks at that complexity. In many ways, the point of genetics is to ignore and bypass that complexity, and concentrate on recombination, mutation, and so on. It is the same with memetics.

Critics would be welcome to discuss the wisdom of applying the existing distinction between genetics and developmental biology to cultural evolution. However they should first understand the proposal. Complaining that genetics seems to ignore developmental processes won't cut it. That is the point of genetics - it specializes in another subject area. That's not to say that developmental processes are unimportant or unrelated - just that they are not the proper subject area studied by the genetics department.

Critics can keep harping on about how memetics ignores the complexities of cultural development - but I don't think they are doing themselves any favours. From the perspective of memetics, they are just wasting their breath and failing to usefully contribute. We know about cultural developmental processes. Yes it is complex = but it is a different subject area. Memetics studies the recipies and the mechanics of how they change. How recipes make cakes is a related subject - but humans are forced to specialize by their limited brains; so academic topics have to be subdivided - and this seems like a highly-appropriate fault line with a proven history in mainstream biology.

Memes are not ‘practices’, ‘approaches’, or ‘traditions’ - any more than genes are cells, limbs or proteins. The point of the idea is to distinguish between heritable information and its expression. Between cultural genotype and cultural phenotype. "Cells", "limbs" and "proteins" are important concepts - but they aren't genes, and they can't be used to replace the concept of "gene".

To recap, the virtue of distinguishing between heritable information and its expression, is that the heritable information is the only thing that lasts in evolution. Everything else is not passed on, not inherited. For many kinds of analysis, it can be ignored. If you look at evolutionary biology you will see the utility of this approach.

The complaint that memetics is reductionistic has some truth to it. It does, after all involve splitting a phenomenon into pieces and analysing the pieces - and the interactions between them. However, reductionism is bedrock of the scientific method. It is the main way that science understands complex phenomena. Reductionism is a very important tool in the scientific arsenal. If you don't use it you will lose useful knowledge. Essentially, if you think 'reductionism' is a bad thing, you need science 101.

Contrary to your claim, using the term "meme" is not a form of intellectual "laziness". Memes are mostly just terminology for cultural evolution. Practically every theory of cultural evolution that has been proposed has some term for heritable cultural information. Boyd and Richerson used "cultural variant". Lumsden and Wilson used "culturegens", Donald Campbell used "mnemones". Carl Swanson used "sociogenes" - and so on and so forth with dozens of meme synonyms. "Meme" is just the term that won the competition between these numerous competing terms.

It is the best term, I think. It is short, and it is reminiscent of "gene" in evolutionary biology. It also lends itself to conjugation - as in "memetic engineering", "memetic algorithms", "population memetics", "meme pool", "memetic hitchhiking", etc. I can think of no better way to gently remind people of the under-appreciated truths that culture plays by Darwinian rules, is subject to natural selection, and is part of biology. No wonder it trounced its competition.

Over 150 years after Darwin, memes and cultural evolution are finally filtering through into mainstream consciousness. There's an explosion of activity in the area. With scientific growth comes scientific conflict - and on the edges of science tempers can fray, misunderstandings can arise - and there can be territory disputes. However, it would be helpful if the practice of "steelmanning" became more widespread. Creating straw man caricatures of opponent positions and trashing them might be fun - but is not all that productive. Progress in science needs critics that attempt to understand the positions of their opponents before trashing them.

Tuesday, 19 August 2014

Cultural kin selection meets anthropology

Anthropologists have long studied cultural kinship. As I put it in my cultural kin selection article:

Anthropologists had previously distinguished between "biological kinship" and "social kinship" (Hawkes, 1983) or between "natural kin" and "nurtural kin" (Watson, 1983) - but they mostly lacked a coherent theory about the evolutionary basis of these categories. Cultural kin selection helps to explain why these traditional anthropological categories are as useful as they are.

However, anthropologists essentially failed to discover cultural kin selection. This was probably largely because of their widespread rejection of cultural evolution - apparently due to fears about eugenics and the like. Scientifically speaking, this was an even bigger mistake.

As a result, attitudes towards cultural kinship within anthropology went in other directions. Anthropologists often seem to see "social kinship" as one of the key reasons for not applying Darwinism to humans. By contrast, in memetics, cultural kin selection is one of the centre pieces of applying Darwinian evolutionary theory to humans. To illustrate the anthropological perspective, here is a quote from Dwight Read's The Evolution of Cultural Kinship: A Non-Darwinian Odyssey:

I take up the question of whether or not the evolution of human societies and cultural systems from a non-human primate ancestor can be accommodated within a Darwinian framework for evolution. I assume that for a non-human primate species, its social structure, form of social organization and kinds of social behavior evolved through Darwinian processes such as biological kin selection, inclusive fitness, reciprocal altruism between biological kin, and so on, including direct phenotypic transmittal of behavioral traits viewed as part of the phenotype of an individual organism. The fundamental question being addressed, then, is whether or not we can embed the evolution of human social and cultural systems within this framework and the conclusion I reach is that the evolution of human social and cultural systems cannot be adequately embedded within this biological framework for the evolution of social systems.

It seems evident that one side of this debate is sorely mistaken. In general, it appears that most of the anthropologists involved are not properly aware of cultural evolution - and their reasoning about Darwinism falls apart at that point. An understanding of memes changes everything.

The cultural green beard effect

One famous discussion of genes recognizing themselves in other individuals who are not necessarily close relatives involves the "green beard effect" - an idea which was christened by Richard Dawkins. He imagined a gene for growing a green beard and another gene that caused altruism to those with green beards - and hypothesized that the combination of these genes might cause a green bearded group of altruists to spread in a population. He then raised the issue of what would stop cheats from displaying the green beard and accepting the resulting altruism, but then failing to be altruistic in return.

In the case of cultural evolution, such "free riders" can often be identified and penalized. A green beard is a form of signalling. Here we will consider a uniform to be a similar form of cultural signalling. If you put on a nurse's uniform and visit a hospital you will probably be found out - if you engage in very many interactions with other staff members. Much the same would happen with an imitation police man in a police station or a fake soldier in the army. The uniform is only one of a large number of cultural traits marking out genuine members of these "tribes" - and it is difficult for an invader to fake all of the required markers. Some tribes develop marks of group membership that are even harder to forge - with piercings, tattoos, bizarre haircuts as well as distinctive clothing, habits and dialects. So: in the cultural realm, cheaters tend to get found out and punished - and that is one way in which the effect can be made to work.

The ideas in the field of tag-based cooperation are a little bit like those associated with the "green beard" effect. Studies of tag-based cooperation have shown that green beards can be less vulnerable to exploitation than was originally thought. For one thing, when a tag or marker is successfully exploited, another tag can be adopted. Also, the whole idea of having genes for altruism towards those with the 'green beards' had always seemed a little bit contrived. Fortunately, this turns out not to be necessary. In cultural evolution, organisms can simply learn which tags best signal altruism in their environment - and preferentially adopt them.

Cultural "tags" or "tribal markers" probably play a number of roles. Knowing who is in your tribe facilitates reciprocal altruism. It indicates who can be punished for defections against group members - and who future interactions can be expected with. Tags also facilitate cooperation based on cultural kin selection. If memes are able to credibly signal their presence in humans, related memes may be able to use the perceptions of their hosts to identify copies of themselves in other people, allowing them to manipulate their hosts to act so as to favour copies of themselves in other bodies. Even without such behavioural manipulation, tags can still facilitate altruism - by allowing groups of cooperators to form and help each other.

The green beard effect has sometimes been used as an alternative explanation to kin selection. Mark Pagel uses the "green beard" terminology - instead of talking about cultural kin selection - in his book Wired for Culture. However it is important to remember that the green beard effect is a type of kin selection. Green beards indicate shared ancestry - and that is still true regardless of whether they are transmitted via DNA genes or culturally. In one case, genetic ancestry is involved. In the other case it is memetic ancestry.