Monday, 8 February 2016

Tribal markers

Tribalism is a largely-cultural phenomena in which individuals signal group membership to other members of their group - and sometimes to outsiders. The signalling is often done using "tribal markers" - where signalling tribe membership is their main function.

Some of the most obvious tribal markers in cultural evolution are uniforms. Sports teams, military, religions, companies and other organizations all use uniforms as means of signalling shared memes. These can then act as targets of altruism via cultural kin selection.

If we classify uniforms as examples of primary tribal markers, then we can also recognise the existence of various secondary tribal markers. For example, badges, bumper stickers and tatoos all function as tribal markers that don't dominate the appearance of individuals. Using secondary tribal markers it is possible to simultaneously signal affiliation with multiple organizations.

Another way to classify tribal markers is whether they are voluntary or not. Most secondary tribal markers are voluntary. However there are many cases where workers are made to wear uniforms where they would not choose to do so - unless they were being paid to do so. Among incarcerated prisoners, uniforms are not voluntary in any way at all. Things like language and money are interesting corner cases. They are often dictated by the rest of the society - giving the individual few realistic options. These also serve other functions besides signalling tribe membership, though.

Another interesting case is markers that denigrate out-groups. Normally secondary tribal markers promote in-group members. In biological systems, competitors are not normally worth wasting resources on. However, the is the phenomenon of local competition. If rivals are few in number - for example because they are nearby - then it is sometimes worth attacking them. In the cultural realm, we see this with negative advertising targeting political rivals. In politics, there are often only a few viable competitors - and it is possible to profit by attacking them. Often such attacks are performed semi-anonymously - and so individuals don't often associate themselves with such attacks. It is observed sometimes, though. Check the bumper stickers (below) for some examples saying: "JAIL BUSH", "TOO OLD", "SCUM", "YUK!" "JERK", "SCHMUCK", "JACKASS", "SHAME" and "IDIOT".

Tribal signalling is an example of memes harnessing our genetic tendencies. Animals often favour their own kin. Tribal markers create cultural kin - kin that share memes rather than genes. A superficial similarity of appearance is created - and this then triggers animal kin-selection circuitry, which fosters cooperation, which in turn helps the memes associated with the tribal markers to spread.

Tribalism has been studied by anthropologists before the advent of cultural kin selection - but they have generally lacked a proper theoretical framework with which to interpret it. While this situation is obviously deplorable, at least there's a lot of data with which to test more modern theories.

Saturday, 6 February 2016

Why cultural evolution is faster

So far most comparisons of the rate of cultural evolution - relative to the evolution of DNA-based creatures - have failed to control for the shorter generation times of memes compared to their hosts. A failure to do this leaves open the possibility that cultural evolution is faster than mammal evolution simply because memes have shorter generation times than mammals do. This is a problem with Charles Perreault's 2012 article on the topic, for example, as I pointed out at the time.

John Wilkins laid down the gauntlet on this issue in 2009, here:

the speed of cultural evolution is pretty much the same as the speed of biological evolution. The problem is that the “rate” is not absolute. Speed in evolution is always relative to generations, not to years. I feel that cultural evolution will tend to be roughly the same relative rate as biological, if only because error rates tend to be at or about the same general level in transmission processes.

However, intuitively it seems as though cultural evolution has led to nuclear power and moon landings in a short period of time - while organic evolution stumbled around for billions of years without doing these things. It seems as though empirically, cultural evolution really is faster, contra-Wilkins.

There's no shortage of theoretical candidates that hope to explain why cultural evolution is faster. In cultural evolution, mutations take place in brains, rather than cells. Variation can arise as a result of intelligent design, using interpolation and extrapolation. Evaluation can be performed under simulation. If you consider brains as containing Darwinian or quasi-Darwinian processes then the generation time there is even faster than cultural generation times - faster even than bacterial generation times.

One of my favorite candidates for a factor that explains the increased speed of cultural evolution involves the distinction between supervised learning and reinforcement learning. In supervised learning, mistakes are corrected by a supervisor, that presents the correct solution. A common alternative to this is reinforcement learning - where actions are scored by a reward function or a utility function. Mistakes are scored, but not corrected.

In organic evolution, organisms are mostly scored - in terms of reproductive success. However, bad quality actions are mostly not corrected. Supervised learning is associated with having a brain. Once you have a nervous system you can often learn using supervised learning. An important function of the brain is predicting consequences of actions - and the most common case of supervised learning involves predicting future sensory inputs. Here, after predictions relating to future sensory inputs are made, sensory inputs are actually received. The predicted and actual perceptions can be compared and supervised learning techniques can be used to correct any mistakes. Though there's no actual supervising agent, this qualifies as supervised learning - since the correct output is presented to the learner on every timestep.

Where does culture come in? Culture makes individual learning add up over the lifetimes of multiple individuals. Without culture, learned information is lost when the individual dies and their brain is eaten by worms. In principle, learned information can still get into the germ line via the Baldwin effect - but that is still a pretty slow process. With cultural transmission, information acquired using supervised learning can directly be passed down the generations and it can accumulate over time.

I won't lay out the case here for supervised learning being faster and better than reinforcement learning - that's part of machine learning folklore.

At first glance, this seems like an argument for psychological evolution being faster than DNA evolution. After all, brains have been around for 500 million years or so. They aren't a new phenomenon. So, how can supervised learning explain how it is only cultural evolution that seems faster? The idea is that psychological evolution is also faster, but that until the origin of culture, it couldn't really go anywhere. Without culture, information in brains is obliterated in every generation and can't really accumulate. As I mentioned, it can still affect evolutionary rates - via the Baldwin effect. No doubt the Baldwin effect does speed up evolution - but it does not do so as much as cultural transmission does.

I think these observations help to address some criticisms of cultural evolution. For example, here's Massimo:

The conclusion that biological and cultural evolution are different also nicely accounts for the fact that cultural evolution is so much more dynamic (it happens much faster) and unpredictable than its biological counterpart. If we think of both as instances of Darwinism that difference becomes more puzzling.

To start with, this is a bit of a straw man, practically nobody is saying that cultural evolution and biological evolution are exactly the same (excepting maybe Ben Cullen).

Anyway, according to the idea described on this page, one of the most significant differences is explained by learning theory - it is supervised learning. The impact of this on evolution dates back 500 million years or so - to the origin of brains. However before culture got started, its influence on the evolutionary process was somewhat muted - due to the regular destruction of information in brains in every generation.

Supervised learning represents a type of feedback from outcomes to the production of new variants to test. In the context of evolutionary theory, this is somewhat similar to Lamarckian inheritance: the inheritance of acquired characteristics. It is however important to note that this is not really a new effect - it dates back 500 million years. Nor can one say that such evolution is not "Darwinian" - since Darwin was an enthusiast for such feedbacks. Indeed, he promoted a theory of "gemmules" which featured feedback from somatic cells to the germ line. What we can say is that cultural evolution is not Weismannian. It features non-selective feedback from the phenotype to the genotype. However, we must also note that evolution in the organic realm is not really Weismannian either. Weismannian evolution - in which phenotypes only affect genotypes via selection and mate choice - was a product of Weismannian's choice of traits. He cut the tails off rats - and observed that this 'acquired characteristic' was not inherited. If Weismann had looked at rat fleas of rat pox instead he might have drawn the opposite conclusion - that acquired characteristics were inherited.

In computer science, lack of access to supervised learning helps to explain the limitations of genetic algorithms and genetic programming - and helps to explain why memetic algorithms are needed.

Tuesday, 2 February 2016

Wanted: analysis of the meme as a meme

Joe Brewer once wrote:

It is a beautiful irony that the “meme” meme won out (as indicated by the amount of attention garnered with it as the label for cultural transmission) using the very evolutionary processes that constitute how cultural evolution actually works.
The story of the "meme" meme is indeed an interesting one. There have been some histories of memetics published. One of the more comprehensive ones is:

I think there's some further scope for analysis of the rise of the "meme" meme.

One of the features of the story is the repeated attacks on the meme concept by confused academics who don't properly understand it. Cultural evolution has featured an ongoing war between academics and popularizers which has, I believe, been a destructive war which has done damage to the field. Presumably, without this conflict, the term "meme" would be even more widely used and understood.

Another interesting feature of the rise of the "meme" meme is its use of memetic hitchhiking on the most viral content on the internet. A massive marketing department probably couldn't have come up with a better plan for promoting the "meme" meme - and yet the whole business with internet memes apparently happened with very little central planning.

Anyway, the rise of the "meme" meme - in competition with the various meme synonyms - is an interesting topic for students of cultural evolution. It's metamemetics! I look forward to the whole topic being given a more comprehensive treatment.

Friday, 29 January 2016

Cultural handicaps

The handicap principle has proved to have some merit in the organic realm. Handicaps can be a form of costly signaling. However handicaps don't need to be in the genes. They can be culturally transmitted. This article is about cultural handicaps.

Boys sometimes handicap themselves in order to show off to girls. They ride bicycles with no hands, they get drunk and take risks and they engage in costly displays of public generosity. The handicap principle suggests that public charitable donations will often be made by men.

Ladies also adopt cultural handicaps. They wear high-heeled shoes, crush their waists using corsets, bind their feet, conceal their faces and mutilate themselves.

Cultural handicaps are celebrated in popular culture. Inigo Montoya and The Man in Black both fight with their left hand in The Princess Bride. Luke Skywalker fights blindfold in Star Wars, A New Hope.

Cultural handicaps are also used in the game of go - where one player disables himself in order to have a fair fight with another. Handicapping is common in sports. There's a Wikipedia page about the topic.

Many ostentatious social norm violations could be seen as being handicaps. Real men wear pink is one example.

So far, cultural handicaps do not appear to have received the same level of study as organic handicaps. This is probably because of the immature state of the science of cultural evolution.


My review of Harnessed is up. I covered the book when it came out in 2011, expressing my approval of the symbiology in it and Mark's use of the M word. However, I only just got around to reading the book. At the end of my review I express my approval of the core idea in the book, "harnessing".

Harnessing as a process similar to domestication. You can sometimes harness a wild animal and put it to use without domesticating it. Harnessing is often a prelude to domestication. As an example of the process, Mark claims that dogs have been domesticated, while cats have been harnessed. I see more harnessed dogs than harnessed cats, but Mark observes that saucers of milk count as a type of harness - in the sense in which he is using the term..

Mark applies the concept of harnessing to cultural evolution - claiming that humans have mostly been harnessed rather than domesticated. Many say that humans have been domesticated by cultural institutions. However, Mark is probably right that these are often cases of harnessing - rather than domestication.

I think that "harnessing" is useful terminology. It is also an important idea for students of cultural evolution. Humans are harnessed in many cases, just as Mark claims. Kudos to Mark for figuring this issue out and sharing his conclusions.

Thursday, 28 January 2016

Memetics: too easy to understand

I've long entertained the idea that the unpopularity of memetics in academia might be associated with the fact that it is too easy to understand.

Notoriously, academia is not about learning, understanding or credentialing folks. It is about social networking and affiliating with impressive individuals. Simple topics are shunned by academics for not being impressive enough to interest them.

I may have got the idea that this applies to memetics from Keith Henson. In 2012, Keith wrote me a private email containing the following:

Mostly I find that the academic types want to make the subject so complicated that nobody outside the field can understand it. They can't because the concepts are just too simple. Thus they ignore it and the work gets done by people disconnected from academia. Kind of a people's science.
Maybe I had the theory before talking to Keith - but his email crystallized the idea for me.

I think that this is part of the explanation for some of the dense maths used by cultural evolution enthusiasts. Lumsden and Wilson's 1981 book makes a good example of this. That book is full of mathematical models. However the models do not really serve any useful purpose - instead they represent a sort of showing off. The authors are attempting to make themselves seem more impressive via their mastery of arcane mathematics.

If Sheldon Cooper and Cartman can understand memetics, academics can't be failing to understand it due to the difficulty of the subject matter.

This theory also explains why cultural evolution enthusiasts reinvented a whole bunch of new models - rather than using ones from epidemiology and symbiology. An esoteric form of cultural evolution is harder to learn - and mastery of it is more impressive.

One of the reasons academics criticize memetics is because it is too simple. For example, consider: Meme Theory Oversimplifies Cultural Change. This critical article has it backwards. The authors are over-complicating their theory of cultural change beyond what is necessary - contradicting Occam's razor. Affiliation theories offer a parsimonious explanation of why academics might behave in this way.

Memeticists studied cultural evolution while academics almost all studied gene-meme coevolution. Trying to study gene-meme coevolution without first fleshing out a theory of meme evolution is like trying to fly before you can walk. How did this happen? Prestige / affiliation theories suggest it is because flying is the more difficult and impressive feat.

Prestige / affiliation theories suggest that memes might be more popular in engineering disciplines. Where the rubber hits the road, so to speak. I can point at memetic algorithms, military memetics and meme-based marketing as examples of cases where this might be true.

An affiliation theory also looks promising if you look at the characters that have supported memes over the years. I don't mean to insult my fellow travelers - but meme enthusiasts have been a motley bunch of oddballs and kooks. Memeticists have often not been attractive candidates for other academics to affiliate with. That creates a vicious cycle.

The affiliation theory presented here suggests that the glacial uptake of cultural evolution might be an internally-generated phenomenon. If so, sad times for science and the truth.

The meme turns 40

The Selfish Gene was published 40 years ago. That makes the meme 40 years old.

Matt Ridley has penned an article celebrating 40 years of Selfish Genes. The article is a good one - but it fails to mention the M word.

Memes could turn out to be the most significant contribution made in The Selfish Gene. Dawkins popularized the nascent field of cultural evolution - making it comprehensible to the layman. Five years later four academics published books on the topic, dragging the topic into the academic mainstream, and the rest is history. While the history of cultural evolution long predates The Selfish Gene, retrospectively, 1976 seems like a significant turning point for the field.

Wednesday, 27 January 2016

Branch dynamics

Tree-shaped patterns in nature are frequently found in both the organic and inorganic domains and demand a common explanation. One type of explanation is a functional one. Many trees efficiently drain basins. Electrical discharges can be modeled as draining electrical charge and propagating cracks do something similar with stress. The maximum entropy production principle generalizes this idea so that it can be applied to evolutionary family trees as well as to physical trees.

An alternative approach to modeling natural tree-shaped systems is to enumerate the type of operation that are possible on them, and develop specific theories for each type of operation. This is the approach taken by Darwinism - which breaks the dynamics of family trees into reproduction with selection, mutation and recombination. Darwinism also applies to branch tip dynamics in other tree systems - since branch tips split, mutate, undergo selection and inherit properties from their parent(s). At the very least they inherit their position.

I've argued elsewhere that positional inheritance is ubiquitous and that this means that many inorganic systems exhibit Darwinian dynamics. For example, the tree-shape propagating cracks, electrical discharges and fractal drainage basins are family trees. In these systems, the branching tips of the trees form a population which is subject to copying with variation and selection. As a result conventional Darwinian concepts of fitness and adaptation apply - and these systems act as optimizers in a similar way to what is seen with genetic algorithms.

With positional inheritance, most physical tree-shaped patterns in nature are regarded as being family trees. However the fact that these trees are physical trees (rather than being historical ones) means that their branches might undergo dynamic changes. Because a family tree is historical its branches form a fixed structure which can't be changed once it has formed. However, the branches of other natural tree-shaped patterns (e.g. streams or with electrical discharges) sometimes do change their structure over time. The branches don't just grow at the tips, they wave and break.

What this means is that we need a theory of branch dynamics - in addition to the Darwinian dynamics associated with the population of branch tips.

Basic branch operations that do not change branch topology include:

  • Branch widening;
  • Branch narrowing;
  • Branch lengthening;
  • Branch shortening;
In addition, branches can be destroyed and sometimes entire branches may also split off or join together. Branches can break without becoming detached if the tree is reticulated (as is fairly common in natural systems). Streams illustrate branch widening, narrowing, lengthening and shortening. Streams get wider as more rain falls and they narrow in times of drought. In meandering rivers on plains, streams lengthen. Branch separation is illustrated by crystals and coral. Sometimes a chunk breaks off without being destroyed. It might go on to start a new colony elsewhere. Branch death sometimes follows branch separation. It can also be a consequence of extended branch shortening or narrowing.

Specific theories relating to these branch operations are generally domain specific. However there may be commonalities between the operations in different domains. Modeling such commonalities is part of the study of branch dynamics, though it is beyond the scope of this post.

Tree dynamics are of theoretical interest because trees are common natural objects. It is also noteworthy that it is possible to recover traditional Darwinism from the theory by considering the special case where the tree branches become fixed once they are created and only the branch tips evolve. The principles of tree dynamics are a superset of those in Darwinism.

Monday, 18 January 2016

Diagram of bank mergers

I've long argued for the importance of merging and joining as fundamental operations in both organic and cultural evolution. Cultural evolution is famous for its mergers. Here's a nice example of merging - from economics:

Thanks to Shannon Vyff for drawing my attention to this one.

Sunday, 17 January 2016

Cultural cancer

Cancer is a common phenomenon in the organic realm - and the parallels between organic and cultural evolution lead us to ask: is there such a thing as cultural cancer?

Organic cancers arise when an organisms' components malfunction and reproduce excessively. Often they threaten to kill their owners.

Artifacts do not normally behave in this way. They are usually not made up of self-reproducing entities in the first place - and so the chances of their reproduction getting out of control is low.

However there are some classes of cultural phenomena that resemble cancers. Cancers feature out-of control reproduction of cells that are not supposed to reproduce at all, or are time-bombed to only reproduce a limited number of times. Many cultural items have deliberately limited reproductive potential - enforced by technical barriers to copying, legal barriers to copying. Technical barriers include DRM and dongles. However sometimes these barriers are circumvented.

Seen in this light, counterfeiting might be seen as a type of cultural cancer. Hyperinflation caused by excessive money printing could be regarded as being a form of cultural cancer too. Copying material which is supposed to be protected from copying by copyright law is another example. Reproduction of private documents on the internet after a 'doxing' attack could also be regarded as being a form of cultural cancer.

A related phenomena takes place with memetic hitchhiking. Memetic hitchhiking often involves a viral vector with an attached payload. However, if the payload is not securely attached, it can sometimes become detached - leaving the viral content to reproduce is an unrestrained manner, without distributing the payload. The type of mutation that leads to this separation can be damaging. This phenomenon could also be regarded as a form of cultural cancer.

We should also consider defining cancer to refer to cases where part of an organism threatens the integrity of the whole. In this case, another range of scenarios start to look like cultural cancers. Enron was destroyed by rogue elements from within. The Shakers could be seen as having been extinguished by a type of ideological cancer - as could Heaven's Gate.

One problem with classifying these type of phenomena as being cultural cancers is that they don't occur inside proper organisms. Rather, companies and religious groups could be seen as being symbiotic unions of multiple creatures (both cultural and organic) - rather like a Portugese man o' war. Rather than looking like cancer, disorders involving one part of a composite creature profiting at the expense of the whole just look like ordinary resource squabbles within uneasy alliances.