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.

Symbiont kin selection

Cultural kin selection proposes that cooperation can arise due to shared memes - as well as due to shared DNA genes.

However, cultural kin selection can be thought of as a special case of symbiont kin selection - an idea that may apply to many types of close living organisms.

Colony life - as found in ants, bees and mole rats - leads to increased levels of transfer of symbionts between the organisms involved (often due to sheer close proximity). The mole rats eat each others feces - and so come to share the bacteria they need to digest their tubers. Ants frequently cultivate fungi - and their nests are heavily dominated by fungi digesting rotting wood. They have many other symbionts too - there are special bacteria that they use to suppress the growth of competing strains of fungi, for example.

As well as acting on the host genes, kin selection acts on the genes of the symbionts too. If the symbionts in different organisms are related, then - to the extent that these can manipulate the behaviour of their hosts in favour of cooperation - they will tend to do so.

Probably ant fungus is the most extreme example of this form of kin selection. Though distributed the fungus is closely related - more so than the ants themselves are. It forms something like a massive multi-cellular organism in each ant colony - a superorganism. It may benefit from that ants acting as a coordinated whole more than the ants themselves do. The ants snack on the fungus - so it probably has a variety of ways of manipulating ant behaviour - through taste, smell and direct chemical action.

Seen from the crude perspective of Hamilton's rule, shared symbiont genes may elevate relatedness further. For example, intra-colony relatedness in naked mole rats has been estimated to be 0.81 - but this relatedness figure is based on the host genes. As with other mammals, most of the genes involved are not mole rat nuclear DNA, but are genes in gut microorganisms. The bacterial cells outnumber those of their hosts by a factor of ten. What happens to that relatedness figure once "horizontal" sharing of bacteria is accounted for? It probably goes up: a lot of those bacteria will be asexual clones.

For an example relevant to humans but still involving DNA genes, consider yeasts - as found in bread, wine and beer. Many yeasts have become human-transmitted symbionts. The main way they spread their genes around in the world involves human social contact. If they can somehow make their human hosts socialize more with other humans, they are likely to directly benefit. Kombucha may be one of the best examples of a socially-transmitted yeast - since it often spreads directly through peer-to-peer contact. Are Kombucha enthusiasts more sociable than other humans? Probably. But are they more sociable as a result of being manipulated by the Kombucha? It is an interesting question that deserves further study.

Symbiont kin selection is a bit different from the symbiont hypothesis of social evolution - but it is fair to say that these ideas are related.

Symbiont kin selection should illuminate cultural kin selection, which can be accurately modelled as a special case of it involving cultural symbionts - rather than DNA-based ones.

Symbiont kin selection is a neglected idea in social evolution. Because of lack of study, it is not easy to assess its overall significance - but it could easily be a big deal. If you look at humans, a lot of their cooperation is based on shared memes - rather than shared genes. In the workplace, for example, shared memes are ubiquitous - and shared genes are rare. Even within family life, shared memes are ubiquitous. Cultural kin selection could easily explain more cooperation than genetic kin selection does. This example illustrates the potential power of symbiont kin selection - but maybe it is equally powerful in other eusocial creatures. More powerful, maybe - since they are further along in the road to colony life than we are. Symbiont kin selection could easily be stronger in them than it is in us.

David Sloane Wilson on cultural kin selection

David Sloane Wilson has weighed in on cultural kin selection. It seems as though he's saying that he doesn't understand how it works - and is hoping others will explain it to him. The good news is that I've already published dozens of articles on the topic that explain it from a wide range of angles.

David's article suggests that his problem is that cooperative cultural interactions take place between organisms which "lack genetic relatedness, genealogical or otherwise". This seems like a basic point that is very easy to explain. Much cultural cooperation is based on shared memes. When two individuals have the same money, the same language or the same religion, they are more likely to cooperate. The more shared memes they have, the more likely they are to cooperate (on average). The idea of cultural kin selection is based on cultural evolution, kin selection acting on memes (rather than DNA genes) and symbiology and manipulation.

David says large spatial and temporal scales are part of the problem. I don't understand this problem. Consider the US dollar for example. This exists in billions of identical copies - and produces a lot of cooperation - which is all well explained by cultural kin selection - since the dollar bills are close relatives with r~=1 - and they clearly influence manipulate their hosts. The dollar's reach is global and it has lasted for quite a long time. It is not clear what the supposed problem with large spatial and temporal scales is.

To reiterate some by-now tired points, kin selection emphasizes close relatedness - where the process actually produces adaptations - such as the human breast. Group selection de-emphasizes relatedness. As a result advocates apply it to groups consisting largely of non-relatives - such as entire tribes - where theory predicts that the process is largely ineffective. As a result group selection has a long (and ongoing) association with junk science.

Mixing cultural evolution and group selection is a recipe for confusion. That's the very last thing the important science of cultural evolution needs. Mixing the two is not helping to educate the public, it seems more like a controversy-based marketing strategy. To me it looks like self-promotion at the expense of misinformation.

To reiterate, it is not the case that group selection explains cultural dynamics that kin selection does not. Group selection enthusiasts have spent decades looking for such cases. They have failed - and now most of them have given up. I thought David Sloane Wilson was among those who had publicly thrown in the towel - and given up this quest. This article suggests that the old group selection dream of finding new science and making original predictions still lives on. That does not seem like a good thing.

A persistent group selectionist hangover

Cultural group selection has led to much confusion. One of the associated confusions is the idea that group selection is more prevalent in the cultural realm than in the organic realm.

This idea appeared prominently in "Not By Genes Alone". Here's what Boyd and Richerson wrote back then:

The real scientific question is what kinds of population structure can produce enough variation between groups so that selection at that level can have an important effect? The answer to this question is fairly straightforward. Selection between large groups of unrelated individuals is not usually an important force in organic evolution. Even very small amounts of migration are sufficient to reduce the genetic variation between groups to such a low level that group selection is not important. However, as we will explain below, the same conclusion does not hold for cultural variation.

It is correct that selection between large groups of unrelated individuals is not usually important. However it is wrong to say that this conclusion does not apply to cultural variation. There the relevant 'individuals' are bibles, dollars and iPhones. These cultural individuals are often related with r~=1. Without relatedness kin selection doesn't work - and neither does group selection.

The idea that group selection works better in the cultural domain has been knocked around by various group selection advocates since then - apparently in an attempt to make cultural group selection seem more plausible. The idea is also beloved of those who like to exaggerate the differences between the cultural and organic realms. The latest endorser of the idea is Razib Khan - in his recent article Language (Culture) and Genes Evolve Differently. Razib gives the following rationale:

Not only is there a great deal of horizontal transmission, but cultural processes are subject to a greater “mutation” rate, and selection can be much more efficacious. The latter is why group level selection is more mathematically plausible for culture than genes; competing demes can be much more distinct in culture than genes because minimal gene flow can equilibrate biological differences, while biased transmission of culture can result in insulation of different groups from homogenization (e.g., inheriting your cultural traits from your father, rather than your mother, who may have been kidnapped from an enemy tribe).

To be plain, there's no supporting evidence for the idea that cultural group selection is any more prevalent than organic group selection. The whole idea is one of the fantasies introduced by group selection advocates.

The now widely-recognized broad equivalence of kin selection and group selection should have obliterated this fallacy - since kin selection is clearly broadly applicable to both realms - and it is patently false that kin selection doesn't apply to the organic realm - as Boyd and Richerson originally claimed for group selection.

In fact, both the organic and cultural realms exhibit superorganisms, eusociality - and all manner of milder forms of kin selection.

Why does the idea that group selection applies more to culture than to the rest of biology continue to lead a zombie existence - long after it has lost any sembalance of a credible empirical or theoretical basis? It isn't clear. Cultural lag is probably involved. Anyway, this article is here to drive another nail into the coffin of this dud idea. R.I.P.

References

• Tyler, Tim (2014) Cultural evolution + group selection = a disaster in the making

Links between organic kinship and cultural kinship

Organic kinship and cultural kinship are clearly linked phenomena. They are linked in several ways:

• Cultural kin manipulate their hosts using mechanisms built by organic kin selection;
• Hosts manipulate each other using kinship cues they acquire culturally from each other;
• Cultural kinship may often be correlated with organic kinship;
• A big family represents a show of strength - but it can be faked with cultural kinship;

The first point is perhaps the most obvious one. For example, uniforms are a product of cultural kin selection: they are produced by making multiple near-identical copies of culturally-transmitted information. However the cooperation between hosts that they produce is largely the result of organic kin selection mechanisms in the brains of human hosts.

The second point is well-known to interview candidates. Mirroring the interviewer makes them like you more. Interviewees are coached to cross their legs the same way, copy the body language, posture and manner of the interviewer. Here culturally-acquired information is again used to stimulate organic kin selection mechanisms.

Thirdly, here's Robin Dunbar (2011) on the topic of kinship correlation:

If there is any degree of consistency between social and biological kinship, no matter how small, then, from an evolutionary point of view, investing in one’s social kin will have the consequence, on the long-term average, of investing in one’s biological kin.

Correlation between cultural and organic kinship may well be fairly mild - but these correlations probably help to explain why the "mistakes" of cultural kinship are not more strongly selected against.

Lastly, being part of a big family can help to create a positive impression. A warrior may think twice if his victim is surrounded by many brothers. A suitor may be more strongly attracted if a woman is surrounded by many sisters. Cultural kinship can be used to create the appearance of a large family.

References

• Dunbar, Robin (2011) Kinship in biological perspective - in Early Human Kinship: From Sex to Social Reproduction (2011);
• Hughes, Austin L. (1988) Evolution and Human Kinship.

Cultural superorganisms

Nature tends to produce hierarchies of organisms. For example, eucaryotes are composed of many previously-free-living cells - and eusocial colonies are composed of large numbers of independently-mobile animals. The easiest way for nature to make large organisms is by clumping lots of smaller ones together. When the interests of organisms in groups become sufficiently closely aligned, they can behave functionally like a single larger organism.

In modern times, we can see this process caught in action at various stages. In an ant's nest, there's still some conflicts between individual ants in a colony - as a result of them having different interests - for example as a result of not sharing all their genes with one another. A Portuguese man o' war shows another type of superorganism under construction. It is not an ordinary multicellular organism but rather a colony - a symbiotic union of a large number of much smaller animals.

Cultural evolution also produces superorganisms. Cultural kin selection and cultural eusociality are usually involved. Companies and religions are prominent examples of superorganisms with cultural components. However, it must be said that these contain organic components as well as cultural ones. Purely cultural superorganisms are mostly something for the future - but we do see some largely cultural superorganisms. Data centres are one of the best examples. There are unmanned data centres - sometimes called "lights-out data centres" - which have no human operators. These can't reproduce without humans yet, but their structure depends heavily on memes. In the future we can expect to see robot swarms - which are even more obviously reminiscent of eusocial insect colonies.

In the organic realm, superorganisms tend to remain colonial creatures. They can't seem to refactor themselves into proper whole organisms. Perhaps doing so doesn't pay - there are probably benefits associated with maintaining a modular cellular structure, to do with regeneration. However, perhaps cultural superorganisms will do a better job of refactoring themselves into first class organisms.

Cultural kin selection may have driven imitation capability

What drove the human ability to transmit culture with high enough fidelity to support the current cultural explosion?

There are a couple of common explanations for this:

• One explanation invokes DNA evolution. This explanation says that acquiring intact memes was beneficial to their hosts - and so acquiring them without error was favoured.

• The other explanation involves cultural evolution. This suggests that culture evolved in order to improve its copying fidelity. Gesticulation led to grunts, which led to speech, which led to writing, which led to printing, which led to the internet - with the copying fidelity increasing at every step. Here the benefits of high-fidelity copying accrued primarily to the memes involved - not to genes.

These explanations are not mutually exclusive - and fairly clearly each played a role at different points in time.

Recently, I've seen another kind of explanation which involves cultural kin selection:

In DNA-based kin selection, your genetic relatedness to another human is an accident of birth - something that you can't easily change. The best you can do is to try and manipulate perceived relatedness cues. In cultural kin selection, the situation is a bit different. The proportion of memes you share with another human is not fixed. You can fairly easily increase your memetic relatedness to another human - by the process of acquiring memes from them - or perhaps their teachers or associates.

It has long been known by psychologists that humans manipulate other humans by imitating them. Interview technique books are full of advice about mirroring your interviewer's posture and copying them in other ways - in order to appear more similar to them. The idea is that this process may have actively pressured humans into improving their imitations skills - in order to appear more similar to other humans, so as to better manipulate them. The improvement could have involved DNA-based genetic evolution, cultural evolution - or a combination of the two.

This is an intriguing story - partly because we can see the process involved acting today. However, I think the idea needs more comprehensive study and quantification. Chimpanzee studies are one area which might illuminate the issue. Chimpanzees have the ability to transmit information down the generations culturally. However do they also imitate each other - in order to appear more like kin to each other? It is an interesting question.

I came across the idea in this article while researching my article on homophily. The paper is in the references for this article. I'm not yet sure where the idea originated.

References

• Haun, D. B. M., & Over, H. (2013). Like me: A homophily-based account of human culture. [paywall] In P. J. Richerson, & M. H. Christiansen (Eds.), Cultural Evolution: Society, technology, language, and religion.

Homophily

Kin selection results in greater cooperation between relatives. A side effect of this is greater levels of interaction between similar organisms. A name has been given to this phenomenon: homophily. As the etymology suggests this term means: liking those similar to you. This idea is captured in the proverbial saying: "birds of a feather flock together".

Here's what Wikipedia says on the topic:

Homophily (i.e., "love of the same") is the tendency of individuals to associate and bond with similar others. The presence of homophily has been discovered in a vast array of network studies. More than 100 studies that have observed homophily in some form or another and they establish that similarity breeds connection. These include age, gender, class, and organizational role.

Individuals in homophilic relationships share common characteristics (beliefs, values, education, etc.) that make communication and relationship formation easier. Homophily often leads to homogamy—marriage between people with similar characteristics.

The term was coined in the 1950s. More recently, a significant literature on the topic has developed.

Kin selection seems to have been largely ignored or rejected as an explanation of homophily - apparently because it takes place between similar organisms - who need not necessarily be kin. However a broader interpretation of kin selection that includes memes as well as genes positions kin selection very centrally as a theoretical explanation of homophily. Almost all similarity in nature is based on copying - whether through blood kinship, mimicry, teaching, behavioural imitation or learning in shared environments. The fundamental logic of kin selection is based on copying heritable information - and so it applies to all of these phenomena.

There have been some studies of the evolution of homophily - including one published in Nature. However, this was Funded by the Templeton Foundation, and authored by kin selection hater Martin Nowak. Needless to say, it makes no mention of kin selection. It's proposal is that homophily offers direct fitness advantages. It gives an example: "homophily may yield fitness advantages because individuals using the same mode of communication may be able to act together more effectively". Sure, but a shared communication system is going to be down to shared genes - or shared memes. Kin selection - or cultural kin selection is thus applicable. Normally a cooperative system featuring shared genes or memes would be followed by mention of the work of W. D. Hamilton. Not here, though: this is ideology, not science.

The study of homophily has resulted in a significant literature, most of which bears pretty directly on the topics of kin selection and cultural kin selection. There's quite a lot of quantitative data available on the topic. Many of the studies involve humans as subjects - helping directly with the study of cultural kin selection. So far, the topic has lacked a central organizing principle. Kin selection neatly explains homophily. The study of homophily to date has produced an abundance of highly-relevant data. Now that there's a good theory to ground and guide our observations of homophily, progress in the area should come more rapidly.

References

• McPherson, M., Smith-Lovin, L., & Cook, J. M. (2001). Birds of a Feather: Homophily in Social Networks.
• Retica, Aaron (2006). Homophily. New York Times. Shankar Vedantam (2006) Why Everyone You Know Thinks The Same As You
• Haun, D. B. M., & Over, H. (2013). Like me: A homophily-based account of human culture. [paywall] In P. J. Richerson, & M. H. Christiansen (Eds.), Cultural Evolution: Society, technology, language, and religion.
• Fu, Feng, Nowak, Martin A., Christakis, Nicholas A. and Fowler, James H. (2012) The Evolution of Homophily
• Torkington, Nat (2006) Homophily in Social Software.
• Shalizi, Cosma Rohilla and Thomas, Andrew C. (2010) Homophily and Contagion Are Generically Confounded in Observational Social Network Studies
• Kossinets, Gueorgi and Watts, Duncan J. Origins of Homophily in an Evolving Social Network

Criticisms of cultural kin selection

Cultural kin selection has faced some criticism. I'll try and track some of the most common objections on this page:

1. Humans are too good at tracking relationships

   In 2008, Boyd and Richerson expressed frank incredulity at the idea that humans are being fooled into thinking that non-relative are relatives - and so behaving nicely towards them. They wrote:

   Living primates are very good at discriminating between relatives and non-relatives and behave very differently toward each. It is hard to see why early hominids should have been less discriminating in their behavior.

   I don't think this is a particularly challenging puzzle. Most primates don't live with rapidly-evolving cultural symbionts who need to manipulate them into coming into peaceful contact with other members of their own species in order to allow the symbionts to reproduce.

   Additionally, memes don't just regard other humans as potential homes of their own future offspring. Other humans are often existing containers for their own offspring, parents and siblings. Memes use the kin-detection mechanisms in human hosts to preserve copies of themselves in other bodies via host manipulation.

   It is these cultural symbionts - which humans have and most other animals don't - that means that the human kin-recognition mechanisms are so frequently the target of successful manipulative attacks. Essentially: the cultural symbionts have short generation times, evolve rapidly and actively seek out the holes in the host kin-recognition psychology.

   Anthropologists have long recognized that kin categories are indeed influenced by culture. For example, they have distinguished between "biological kinship" and "social kinship" (Hawkes, 1983) and between "natural kin" and "nurtural kin" (Watson, 1983). That kinship relationships can be significantly influenced by culture is really a commonplace fact these days.

   Also, other species are not completely immune from this sort of kinship-based manipulation. For example, cuckoo hosts are regularly fooled into thinking that cuckoo chicks are their kin - and into providing resources for them. Notice that active manipulation by a symbiont is also involved in this case. In the case of cuckoos, succeess comes to them not because their genes evolve rapidly compared to their host - but because they are relatively rare - and so are not worth defending better against.

   Lastly, I think that there's a bit of a straw man in the framing of this objection. In cultural kin selection, people are not normally literally fooled into thinking that non-relative are really relatives. Instead they are fed sensory sitmulii that act as a superstimulus to kin detection routines in their unconscious minds. If you ask brother Mark whether brother John is a blood relative, he will probably give the correct answer. However this doesn't mean that their shared memes and shared monastic robes aren't relevant to the extent of their cooperation. Manipulation can take place unconsciously. Also: relatedness isn't a binary quantity; there are degrees of relatedness. Memes can and do massively increase levels of perceived relatedness between their human hosts - and it makes sense that they do this partly to increase their own inclusive fitness.

2. Relatedness is hard to estimate in cultural evolution

   Here is Peter Richerson in 2010:

   In the case of culture, the analog of kinship is very hard to estimate. Having two parents with equal genetic contribution makes the calculation of relatedness easy. In cultural transmission, one, two, a few, or many people in your social network are possible sources of culture. People may use different parts of their network for different cultural domains. No one has proposed a way to estimate cultural relatedness in the face of such problems.

   I have previously worked through this objection in my article on cultural kin selection - in the section titled "memetic relatedness". To recap: it is not true that no one has proposed a way to measure cultural relatedness. Also, relatedness between two humans is one problem, and relatedness between two artifacts or two messages are different problems. The latter problems are significantly more tractable. Cultural information spends some of its time inside brains and some of its time moving between brains - and during these "external transmission" phases, it is often much easier to quantify it.

   It is often harder to measure relatedness in cultural evolution - due to the lack of meiosis. However, this is not a show-stopping problem. Not all creatures in the organic realm feature meiosis in the first place - yet they still have relatives and must allocate resources between themselves and their offspring and parents. The theories associated with kin selection still apply in these cases.

   Cultural relatedness is often easy to calculate. For example, Alice's dollar bill is related by around 100% to Bob's dollar bill, and around 0% to Charlie's Japanese yen. Also, having some relatednesses that are difficult to quantify is not a problem unique to cultural evolution. For example, in organic evolution, it isn't easy to measure the relatedness to two Portugese man o 'war individuals. The fact that they are a symbiotic conglomerate is a complication - but not a show stopping problem.

3. Maximization of inclusive fitness may not apply "commonly"

   In 2014, Dan Sperber (and coauthors) wrote:

   How deep is the analogy between biological and cultural evolution? Memetics assumes that it is deep indeed; that the main relevant details of the biological case have direct equivalents in the cultural case, such that there is, for example, a cultural phenotype, which achieves a certain level of (inclusive) fitness, which will in turn determine the phenotype’s relative success in the population.

   This is good so far, though I would identify this as a conclusion from many decades of observations - rather than an "assumption". The authors go on to say:

   Darwinian selection leads to the maximization of inclusive fitness, and this explains the appearance of design in the natural world. Is there an analogous result for cultural attraction? As selection is a special case of attraction, design is possible and in some cases explicable in standard Darwinian terms. Having said that, such explanations will not apply generally, and may not even apply commonly.

   The concept of "inclusive fitness" is a simplified model of kin selection which no-one believes applies generally. However, kin selection is a very generally-applicable idea - it is a consequence of natural selection itself in structured populations.

   As for the generality of Darwinism itself - it all depends on what you mean by the term. I think most accept that evolutionary theory has moved on a bit since Darwin's era - with the incorporation of symbiosis, game theory and an understanding of self-organizing systems. However, many still use the term "Darwinism" for the resulting evolutionary theory - as a way of giving Darwin credit for coming up with the basic idea in the first place. Ultimately, this is a terminological issue.

   Personally, I don't like Sperber's various terminology proposals. In fact, I think that they suck. "Attraction" is a basic concept in dynamical systems theory. If you want to redefine it, you had better have a good case. Sperber doesn't present such a case; he doesn't have one. Overloading the term with multiple similar meanings is not an attractive option.

4. Criticsms of group selection - and cultural group selection

   Kin selection and group selection are broadly equivalent - so many criticisms of group selection also apply to kin selection - and many criticisms of cultural group selection also apply to cultural kin selection.

   For example, Max M. Krasnow & Andrew W. Delton argue that there is no evidence for group selection in humans - in: "Is there evidence for special design of a group-selected psychology". They say:

   The debate is not about selfishness versus generosity or individualism versus groupishness. The debate is about whether generosity, cooperation, altruism, etc. are instantiated by a psychology designed by individual or group selection. If the former, then this psychology should have design features that, on average and under conditions that match ancestral conditions, eventually lead to net benefits for the individuals or their kin.

   However, this is a bad framing of the problem. Modern versions of kin selection and group selection are equivalent - and make the same predictions. If you argue against group selection on the grounds that kin selection is responsible, you haven't understood this - and so can't really usefully contribute to the discussion.

   Another example is Steven Pinker. He criticizes group selection, cultural group selection and cultural evolution in The False Allure of Group Selection. Pinker's arguments vary from being reasonable to being wrong. Overall, he has no coherent case against group selection, cultural group selection and cultural evolution - assuming the group selection variants are interpreted as being equivalent to the corresponding kin selection theories.

   Pinker's article is remarkable in including a lot of commentary - which illustrates how much confusion surrounds these topics on all sides.

5. It all boils down to genes

   Wilson-style sociobiology - and most evolutionary psychology - has long held the opinion that in biology, it all boils down to DNA genes. That DNA genes are the only medium of inheritance in evolution that matters. Memes are ignored - and all advantage is ascribed and attributed to DNA genes. From the perspective of memetics, this position seems ridiculous - but it seems to be a remarkably mainstream position.

   In the context of cultural kin selection, uniforms become a way for humans to manipulate other humans. Holy fathers and mother superiors become ways for church leaders to manipulate their flock. Rather than memes manipulating humans for their own benefit, humans are seen as using memes to manipulate other humans - for the benefit of their own DNA genes.

   There's obviously some truth to this perspective. Human genes do often benefit from the manipulations described by cultural kin selection. Military leaders do benefit if their army behaves as though it is a big family.

   The problem arises when advantage to memes is completely neglected. This tends to result in an impoverished perspective on the evolutionary process, which loses much of its explanatory power. Those who think that only genes matter are missing half of the picture.

Recent criticisms of kin selection itself deserve a mention here. Group selection advocates have long been critical of kin selection - arguing that kinship is only one of many ways in which organisms can come to share features, that group selection is more general, that inclusive fitness is a awkward, artificial concept, that kin selection is too hard to apply - and so on.

In some cases widespread criticism from the scientific community pointing out that some of the more extreme critics are plainly off their rockers has helped with some of this.

Widespread recognition that kin selection and group selection are broadly equivalent concepts and represent different perspectives on the same kind of phenomena should help to damp down some more of these criticisms.

However, kin selection has had its flaws. The widespread failure to apply kin selection to cultural phenomena is one of these. This failure is explicitly mentioned by some critics - e.g. here. However, that is not so much a problem with kin selection, as it is a problem with the scientific failure to get to grips with cultural evolution. Anthropologists - whose job largely involves studying human culture - are mostly-living in a pre-Darwinism timewarp - in which evolutionary theory is not applied to their subject matter. The way to deal with this is not to use kin selection less, but to use cultural kin selection more.

While kin selection is not without issues, these seem minor into comparison with the problems with group selection. Group selection seems to be a fountain of junk science. I think it should come with clear health warnings - and, generally speaking, it does do so.

Anyway, this probably isn't the best place to review the whole kin selection vs group selection debate. I do have another blog where that is one of the main topics.

Kin selection has been a tremendously useful and productive tool in the biological sciences, and there is absolutely no reason why it can't be similarly useful and productive in cultural evolution - and in the social sciences generally. At this stage, scientists just need to pull their fingers out and start applying it. Hopefully, my reviews of the topic have indicated the abundance of low-hanging fruit in this area.

Tim Tyler: Cultural kin selection

Transcript:

Hi. I'm Tim Tyler - and this is a video about cultural kin selection.

This is a big and important topic which must be condensed for this kind of format - so this is a "firehose" presentation on the topic.

Nepotism is a common phenomena in nature. It has long been understood that evolutionary theory could help to explain why organisms help their relatives. However it wasn't until the 1960s that the process responsible for nepotism was formally modelled.

William Hamilton visualized the germ line of organisms as being broken up into many genes. Each gene is surrounded by many copies of itself in its relatives. It then becomes possible to ask what behaviour the gene could promote that would help the swarm of genes to propagate itself. The answer indicates that there are circumstances under which genes can favour transferring resources to other existing copies of themselves at the expense of their own direct descendants.

The theory that quantifies and explains this phenomenon is known to biologists as "kin selection".

It is a commonplace observation that cultural similarity also results in cooperative behaviour. Empirically, there's a correlation between the memes that people share and how likely they are to cooperate with one another. Memes resulting in observable markers seem particularly significant - so the uniforms worn by the military, nurses, religious orders and corporate workers are especially closely associated with cooperative behaviour. The most conventional explanation for this is known as "fictive kinship". The idea is that shared uniforms stimulate mechanisms evolved to deal with kinship at the level of DNA genes. The kinship involved is not real blood kinship, but rather has been faked by leaders of these groups for their own ends - thus the term "fictive kinship".

However, another explanation invokes cultural kinship. The theory of kin selection is not confined to DNA genes. It can equally be applied to memes. Shared memes often result in cooperation in the same way that shared genes do. Like DNA fragments, memes are frequently surrounded by a swarm of copies of themselves. Again, it is possible to ask what behaviour promoted by the meme would serve to promote the propagation of the swarm of copies surrounding it. Again the answer indicates that memes will sometimes sacrifice themselves to promote the propagation of other copies of themselves. The theory that explains this is called "cultural kin selection" - and that is what this video is about.

Cultural kinship helps to explain why nurses wear similar uniforms to each other and cooperate with one another. Shared memes help to explain explains why your computer and your printer peacefully cooperate to print documents. Nuns form cultural "sisterhoods" and monks form cultural "brotherhoods". Their lives are often dominated by the memes they share, and their mission in life is typically to spread these memes to others. Patriotism memes illustrate that memes can sacrifice themselves if it helps copies of the same meme in others to survive. Cultural kinship is an essential tool for understanding how memes propagate the modern world.

In the organic realm close kinship sometimes results in eusociality - where a fertile queen is surrounded by multiple sterile workers. We see the same phenomenon in culture - banks are surrounded by millions of identical coins and bills. These are not themselves copied. Indeed there are cultural adaptations which actively prevent counterfeit copies from being made. The function of these multiple identical cultural entities is to divert resources to their cultural parents in the bank. Another familiar case involves digital books. these exist in multiple identical copies. However most of the copies themselves are not fertile. Digital rights management and legal threats are used to try and prevent them from being copied.

Sterile worker forms are one of the tell-tale signatures of kin selection. The other one is self-sacrifice. Memes that spread despite apparently aiding their personal destruction could be being spread via cultural kin selection. Patriotism memes and suicide bomber memes are possible examples.

Kin selection is famously associated with Hamilton's rule. To briefly recap, Hamilton's rule measures the cost to a donor and the benefit of a recipient associated with a behaviour and the relatedness between the actors. It then asserts that the behaviour can be favoured by kin selection if the benefit is greater than the cost multiplied by the relatedness. This simplified model of kin selection has proved to be quite useful in the organic domain. However its utility depends partly on the ease of measuring relatedness. In the organic realm, there's a simple approximation that can be used: parents are related to offspring by one half, cousins by one eighth - and so forth. Ultimately these fractions come from meiosis. However, there's not really a direct equivalent of meiosis in cultural evolution - which makes it harder to apply Hamilton's rule. Humans don't share half their memes with their parents and one eighth of their memes with their cousins. However they do typically share more memes with their parents than with their cousins. If you consider the topic of relatedness between artifacts, measuring relatedness often becomes easier - because it is easier to measure memes in artifacts than it is in brains.

It has long been understood by anthropologists that "cultural kinship" exists in humans. Humans treat all kinds of people who are not blood relatives as though they are honorary family members. Churches in particular are full of father, mother, brother and sister relationships which do not reflect any form of blood-based kinship. However, most anthropologists have historically had a weak understanding of evolution - and have reacted with hostility to the efforts of biologists to enter their territory.Many anthropologists seem to associate evolutionary theory with racism and eugenics. Cultural kinship has been regarded within anthropology as evidence that Darwinian evolutionary theory applies only weakly to human behaviour - and that cultural forces are more important. This wilful ignorance of evolution meant that they failed to find a coherent theoretical foundation that would account for their observations.

Cultural kin selection casts new light on this topic. On the one hand it shows that the anthropologists were correct to emphasize the significance of cultural kinship. However, on the other hand, it also shows that the evolutionists were right on target with their Darwinism. Cultural kin selection neatly explains the importance of cultural kinship in humans from within an evolutionary framework that includes the concept of shared memes.

Lastly, cultural kinship offers an intriguing glimpse of scientific history repeating itself. In the 1960s, group selection was a popular theory - before kin selection displaced it. Now, 50 years later, cultural group selection is a popular theory. However, kin selection is much better than group selection. It puts an entirely appropriate emphasis on the significance of close kinship, it more strongly encourages quantification and is less strongly associated with junk science. Group selection has proven itself to be a confusing and misleading tool for understanding essentially the same set of phenomena that kin selection explains. Consequently, the same dynamics that we saw in the 1960s are now evident again. A similar sequence of events seems to be playing itself out with cultural group selection and cultural kin selection. This case of history repeating itself in science gives us an interesting opportunity to quantify the scientific lag that cultural evolutionary theory suffers from. By this metric, it's about 50 years behind mainstream evolutionary theory.

There's a lot more to say about this topic - far more than can possibly fit into this video. Search online for "cultural kin selection" for much more information about this subject area.

Enjoy,

Cultural evolution + group selection = a disaster in the making

Cultural evolution has fought for acceptance for over a century - against fierce opposition from anthropologists, philosophers - and even some evolutionary biologists.

Now, as the penny shows signs of finally starting to drop, some proponents of cultural evolution seem to have got the idea that it is a good move to link the theory to another controversial theory: group selection.

I think this is likely to be a disaster for the public understanding of science. Such a link will cause confusion for lay scientists attempting to understand the theory. It is likely to result in delays is the adoption of cultural evolution. It is also likely to result in misapplications of the theory of cultural evolution.

Linking one controversial theory to another one just risks compounding confusion - and let's face it, cultural evolution is a much more important than a methodological squabble about what accounting method to use in which organisms share heritable information. Modern versions of kin selection and group selection don't even make different predictions. Scientifically speaking, the issue is a bit of a storm in a teacup.

About the only possible favourable outcome I can see is that the controversy associated with group selection might add to the eyeballs scrutinizing cultural evolution. However, group selection is a dodgy theory which adds no new predictions to our existing understanding of science - and it has a long association with junk science - due to it being systematically applied to the cases where kin selection doesn't obviously work.

I think that a much bigger risk is that cultural evolution will be tarred by its association with group selection. Exhibit A for this is the 2012 "Stephen Pinker" controversy. Stephen Pinker is obviously a smart cookie - but he doesn't understand cultural evolution or group selection. However he does know enough about group selection to realize that it is dodgy. Richard Dawkins described it as "A Cumbersome, Time-Wasting Distraction". Not "wrong" - but not very good either.

Anyway, I wish that cultural evolution enthusiasts would put group selection down. They adopted it in an atmosphere of confusion - without a good understanding why group selection was in the dog house. For example, Henrich (2004) wrote in his defense of using the "group selection" terminology:

Concerns and confusions related to Wynne-Edwards (1962) work of over 40 years ago should, in my view, be relegated to history books

However - alas - it isn't as easy as that for group selection to clean up its act. Group selection was driven into the fringes of science by kin selection. It is consistently applied by advocates to cases where relatedness is low - and so the theory doesn't work. It is systematically not applied to cases where relatedness is high - and it is obvious to everyone that "kin selection" did it.

Given group selection's ongoing association with junk science it is just the sort of thing we don't want linked to cultural evolution. Cultural evolution faces strong resistance from within anthropology. One of the many complaints is that those seeking to biologize culture are using naive biological theories, and are doing it wrong - with the potentially significant costs associated with applying these theories to humans. Of course this is a pretty feeble excuse for rejecting Darwinism entirely - but looking at Wilson-style sociobiology, they were partly right - the treatment of culture by these theorists was hopeless. Looking at modern evolutionary psychology they are partly right again - the treatment of culture by these theorists is equally hopeless. Only memetics (and similar theories) take cultural variation seriously as an evolutionary phenomenon - and so has a hope of eventually being accepted by anthropologists. Tying cultural evolution to group selection just creates another opportunity for anthropologists to reject it as "bad science". It's surely a bad strategy which will only hold the field back. Forget about group selection. It's completely unnecessary - and it will just create endless confusion - as it has been doing now for decades. Surely that is the last thing we all want.

Cultural kin selection and the meme revolution

Kin selection played a significant role in the gene revolution. As William Hamlton put it:

We need to descend to the level of the gene, rather than the individual, in order to see that the gene exists surrounded by copies of identical genes that exist in all its relatives [...] Seeing this swarm of genes that exists around a particular one, we can then ask what is the behavior caused by this gene that is most likely to cause the propagation of this set of copies in the relatives around it.

This "descending to the level of the gene" is known as "the gene's eye view".

Just as kin selection led to and helped to promote the gene's eye view - so cultural kin selection will help promote the meme's eye view.

The meme's eye view has always been part of memetics, but is has been largely ignored by social scientists. Many of them are absurdly confused about the 'meme' concept - complaining that it atomizes cultural wholes into isolated pieces, or that replicators are only one part of evolution - or a string of other equally silly objections.

In 1985, Boyd and Richerson explicitly focused on the human hosts involved, saying:

This does not mean that cultures have mysterious lives of their own that cause them to evolve independently of the individuals of which they are composed. As in the case of genetic evolution, individuals are the primary locus of the evolutionary forces that cause cultural evolution and in modelling cultural evolution we will focus on observable events in the lives of individuals.

This rather myopic perspective has lasted for thirty years - with most analysis of cultural epidemiology focusing on the human hosts - and not on the memes themselves.

As Steven Shennan put it in 2013:

The variation, selection and retention processes that underlie cultural evolution were laid out in detail more than 25 years ago (Cavalli-Sforza and Feldman 1981, Boyd and Richerson, 1985) and have been extensively elaborated on since (e.g. papers in Boyd and Richerson, 2005). However, this has mostly been done from an agent-centred perspective and not from that of the cultural lineages themselves - the "memes eye view" - and the two are not the same.

It seems reasonable to expect that the rise of cultural kin selection will significantly promote the "memes eye view". From the perspective of memeticists this will be a long overdue development - since it is what they have been saying all along.

Memetics has been ahead of its time for far too long. Looking at the scale of cultural evolution's scientific lag in academia, it seems reasonable to expect that cultural kin selection will start becoming more prominent in academia around about now. It seems practically inevitable that this will drag the "meme's eye view" (and thus a big chunk of memetics) into academia as well. It will be about time.

References

• Tyler, Tim (2014) Cultural kin selection.
• Tyler, Tim (2014) The gene revolution.
• Tyler, Tim (2011) The meme's eye view.
• Tyler, Tim (2013) Cultural evolution's scientific lag.
• Tyler, Tim (2014) The host-centric approach to cultural evolution.
• Tyler, Tim (2013) Memetics: ahead of its time.
• Tyler, Tim (2014) Why we need memetics in academia.

Cultural kin selection vs cultural group selection

Cultural kin selection is kin selection acting on cultural symbionts. Similarly cultural group selection is group selection acting on cultural symbionts.

As part of the deep relationship between organic and cultural evolution, the history of the cultural versions of these fields seems likely to mirror what happened in the organic domain - though it is widely observed that cultural evolution and memetics suffer from a large scientific lag.

In the organic realm, group selection was popular until the 1960s - when it was practically wiped out by kin selection. At the moment, cultural group selection is a popular form of explanation. My expectation is that it will be largely wiped out by cultural kin selection.

If modern forms of kin selection and group selection make the same predictions, why is kin selection better?

The advantage of using kin selection is partly down to a difference in emphasis. The term "kin selection" emphasizes close relatedness - which is an important factor in why the theory works. The term "group selection" makes no mention of family or relatedness. This seems to cause group selection enthusiasts to neglect the significance of relatedness - and then go off the rails.

Group selection is probably more popular initially because it is easier to understand and apply. Without quantifying relatedness, armchair theorists are free to speculate about traits being adaptive at various different levels. However, for group selection, this ease of application also contains the seeds of its downfall. Scientists love to measure things, and kin selection's famous r, b and c encourages quantification. This leads to more rigorous science. It also gives kin selection a higher status among scientists.

In the organic realm, kin selection won out in the 1960s and 1970s. However in the social sciences, many researchers in the domain of cultural evolution - Richerson, Boyd, Bowles, Gintis, Sober and Henrich and Turchin - have adopted the term "group selection" - despite the fact that the term is historically mired in confusion and misunderstandings and has led to a substantial body of junk science. Practically the whole of the rest of the evolutionary biology establishment prefers the kin selection framework instead. Kin selection pushed group selection into the scientific fringes.

I think the most obvious hypothesis to explain the situation is that the social scientists are lagging behind the times. Cultural evolution's scientific lag explains the observed phenomena neatly. The social scientists are about forty years behind the times. The idea of cultural evolution having a scientific lag predicts that the current enthusiasm for cultural group selection will be largely replaced by a substantial blossoming of cultural kin selection.

The coming displacement also makes sense after looking at the way in which the theories have been applied to date. The group selection theorists have only scratched the surface of the topic - concentrating on large-scale conflict between human groups. However cultural kin selection has a vastly broader domain of applicability than this. The group selection theorists fail to concentrate on close relationships. Yet this is precisely where theory predicts that the largest effects will be found. The enormous significance of close cultural kin has been largely ignored. There's a wealth of material relating to cultural resource allocation and cultural parental care, which kin selection illuminates better than group selection does. The approach based on group selection approach has been tried by social scientists - and the results are in. The approach has been a miserable failure. Cultural kin selection will be vastly superior by a wide range of metrics.

Cultural spite

Kin selection has a well-known dark side: Hamiltonian spite.

Genes can promote their interests by causing their owner to help relatives - which is the familiar kind of kin selection - or by causing their owner to hinder non-relatives - which is generally known as spite.

Initially, it was thought that paying a cost to hinder non-relatives was rare. Several reasons were given. Harming others often has significant associated costs - they can bite back. Relatives are often neighbours - making them easier to identify and more likely to be interacted with. Also it was thought that a very large number of non-relatives would need to be harmed (especially in large populations). Overall it seemed as though spite didn't add up.

While plenty of individuals do deliberately harm other individuals, they often benefit in some way. This theory of "selfish competition" explains phenomena such as male combat, sibling rivalry and competition between saplings to replace their parent in the canopy. This theory seemed to make a lot more sense than Hamiltonian spite.

However, Hamiltonian spite did bounce back to some extent. Though initially the search for Hamiltonian spite focused on small populations, it was realized that the size of the population of local competitors was what really mattered. Population viscosity would often mean that this was just a handful of individuals. Gardner and West cover this revolution in their paper Spite and the scale of competition. They say:

When competition is global and fitness is proportional to absolute success, spite cannot be favoured, but as competition becomes increasingly local fitness is increasingly determined by success relative to social partners, so that spite can be a winning strategy.

With this background, we can now turn to cultural spite. As in the organic realm, cultural spite is predicted by theory, but seems relatively elusive in practice.

• Patriotism memes. These really do manipulate their hosts into fitness-reducing acts while benefitting near-identical copies of themselves in other individuals - comrades, generals, and propagandists. These appear to be a genuine case of cultural kin selection. Interestingly, patriotism memes sometimes seem to be implicated in acts that directly harm other individuals. In particular they are implicated in conflict and warfare. Could this be a real-world case of cultural spite?

  Maybe - but there's some room for doubt. In many cases, warfare generates kill-or-be-killed situations. When the benefit is survival, "selfish competition" is a more obvious explanation for the resulting conflict. The situation in warfare is complicated, and the link to spite is rather speculative and indirect. Patriotism memes are an interesting candidate case of Hamiltonian spite in culture - but it doesn't seem like an open and shut case.

• Negative advertising in politics. American politics regularly features negative advertising. As well as hearing the good things candidates will do, citizens hear all about the bad things associated with competing candidates. When they outsource jobs, when they raise their own salaries, when they act like puppets of other politicians - and so on. An explanation in terms of spite is straightforwards: this is a case where the effective population size is small (and so spite can work). Also, destroying things is easier than creating them. The winners do contain DNA genes, but politics is also a battle between rival memeplexes. The main problem with this example is that it can be argued that the behaviour is merely selfish - since the advertising sponsor (or their affiliates) gain many of the votes lost by the target.

Another promising area to look for spite is corporate history. There may well be cases where companies have a limited number of competitors - and there will have been scope for acts where a company hurts itself, but hurts its biggest competitor more. However, this is research that remains to be done. The problem here is that individual acts that look spiteful would not be too impressive. What we would really like to find is spiteful adaptations. Corporate history may be less promising in this regard.

These are the strongest case for real-world cultural spite that I am aware of. However, they are not very convincing. If more convincing examples of cultural spite come along, I'll update this page.

Technological kin selection

The realm of technology is full of systems that cooperate with one another. Printers, cameras and monitors all cooperate with computers. Computers cooperate with networking systems which cooperate with all manner of other devices. How are we to explain this sort of cooperation?

There are two kinds of answer to this question:

• These machines were designed by humans to benefit humans, and they cooperate because this serves humans;
• The machines share memes with each other, so Hamilton's logic of kin selection predicts that they will cooperate;

The first explanation is fairly obvious and makes sense. It is the kind of explanation that evolutionary psychologists might give. The second explanation invokes cultural kin selection. It invokes the meme's eye view and is in the sprirt of memetics. It is one of the ideas I discussed in my 2012 "Cultural kin selection" article.

The idea that artifacts that cooperate to the extent that they share memes has considerable merit. There's certainly a correlation: 100% shared memes often results incomplete cooperation - while 0% shared memes generally results in fairly minimal cooperation which is explicable in terms of reciprocity and byproduct mutualism.

As an example of how the process works, let's look at the cooperation that takes place between a printer and a computer when they print a document together. Without that cooperation, no documents would be produced - and the consumer would be frustrated. This could potentially damage the memes in the devices themselves - for example, maybe the printer will be thrown in the trash if it was identified as the defective component. However, the memes in the printer were terribly unlikely to reproduce directly in the first place. The main way they can influence their own propagation is via copies of themselves in the headquarters of their manufacturer. Part of the consumer's frustration will probably be directed towards the manufacturer. This might affect future purchases by the consumer involved. The consumer might mention the problem to other prospective customers. For example, they might write a negative review or tell the story to others. The cooperation between the computer and the printer happens because of benefit to copies of the memes involved at the headquarters of their manufacturer involved.

This example shouldn't be taken to imply that the effect is confined to computer peripherals, a wide range of cooperating artifacts exhibit cooperation which is based on cultural kin selection.

There are some cases where shared memes in some sub-component or interface seems to be more important than overall shared memes. However, if you view single artifacts as symbiotic conglomerates with components from many sources, this still makes a lot of sense - and a kin-selection based approach is still highly appropriate. There also be cases where shared memes in the associated manufactures (rather than the device itself) seems to be a factor. Consumers certainly use the manufacturer as a clue to compatibility - for example with printer cartridges. However, this is just a proxy for shared memes in the artifacts. If looking to the identity of the manufacturer is helpful, that could be a complication when applying the approach.

Technological kin selection has gradually moved from being a minor factor in explaining cooperation on the planet to being a pretty significant one. As we move towards the memetic takeover, technological kin selection seems likely to continue to increase in significance.

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 shop creates a descendant shop nearby, that might make it easier to set it up the second shop. Close proximity makes it easier to share employees, stock, resources and training. However the stores might go on to compete with each other for customers. If there are multiple descendant shops, a failure to disperse them widely can also mean that the descendant shops compete with each other.

A form of kin competition is often observed acting between related products from the same company. On one hand, companies want to produce a diverse range of products - to expand and saturate the niche represented by their market. However, their products are similar and often compete with each other. This situation can be modeled by treating the products as sterile workers, and then applying the theories associated with kin selection and kin competition.

A similar effect can be found in academia. For example, where memes inside one professor might be reluctant to propagate themselves into another similar professor in the same department - or both professors will soon be expending their resources in fighting over the same grant money - a fight which can be simply avoided if meme reproduction is delayed until after the grant is awarded.

If there are multiple offspring organizations, they often compete with one another for resources from the parent organization(s). This is an example of 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.

As is seen in the organic realm, cultural kin competition promotes dispersal. There are fewer conflicts over resources if offspring are widely separated in space.

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.

Cultural kin selection vs memetic engineering

One of the reasons why kin selection makes useful predictions is that it depends on a long history of interactions with kin, allowing the evolutionary process to 'learn' about the significance of these relationships. However, in cultural evolution, engineering could be used to produce more-or-less any behaviour towards kin that the engineer likes - reducing the predictive value of the coefficients of relationship used in kin selection theory. This is potentially a significant issue for those studying cultural evolution - since many memes are, at least partially memetically engineered.

An alternative view of (say) military uniforms is that they are the products of memetic engineering by generals who want to manipulate their troops into higher levels of cooperation with each other by exploiting the association between perceived kinship and cooperation. This then benefits the generals - and probably their genes. This sort of picture sounds plausible - and makes no mention of cultural kin selection. The explanation that military uniforms are memetically engineered by generals apparently fits the facts without invoking cultural kin selection.

The first thing to note is that military uniforms are actually an ancient phenomenon with a long evolutionary history - and so there's considerable scope for evolutionary and selective forces to act. The other main point is that explanations in terms of benefits to humans and benefits to memes should not necessarily be seen as being alternatives to each other. If you have gene-meme coevolution, often there is evolution towards mutualism - in which both genes and memes evolve to avoid being damaged by the other party. Occam's razor suggests that when two explanations of a phenomena are offered, often only one of them is true. However, in cases of gene-meme coevolution the explanations that "genes benefit" and "memes benefit" are often both true - because of the phenomenon of evolution towards mutualism.

Memetic engineers could engineer whatever memes they like. However, it is often easier to reuse memes that are already available. Also, engineers typically want the memes they engineer to spread. In those cases, making memes that can help copies of themselves in other bodies is one way of doing that - so memetic engineers can be expected to engineer kin recognition and kin-based cooperation into their products - in much the same way that natural selection often does. Having an intelligent designer involved doesn't usually change what forms are adaptive, but it does allow adaptations to arise more quickly. Intelligent designers could fight against natural selection - by engineering forms that are maladaptive. However, only rarely are they motivated to do so. It is quite common for them to want their products to be popular and successful.

It is no accident that the uniforms of military, sports teams, religious orders, hospital workers and so on use culture to make their wearers resemble kin. The producer of this adaptation could be an intelligent agent, it could be evolution via natural selection - or it could be a combination of the two. Memetic engineering is only superficially a rival explanation to cultural kin selection. It is better to see memetic engineering as a rival to the hypothesis of "unintelligent design" - of natural selection without minds. Cultural kin selection can still be applied in either case.

The significance of cultural kin selection

Kin selection is an important and central part of the theory of evolution via natural selection. In turn, cultural kin selection is important and central part of cultural evolution.

Kin selection was originally discovered in the 1960s. It contributed significantly to to an enormous revolution in our understanding of evolutionary biology - the gene revolution.

The discovery of kin selection and intra-genomic conflict destroyed the idea that organisms acted as harmonious wholes. Instead, it became clear that organisms were uneasy alliances between factions with overlapping - but different - interests.

As in the organic realm, cultural kin selection is invading territory that was previously occupied by inadequate group selection theories. Today, group selection enthusiasm still rampant in the social sciences. In the organic realm, the switch from group selection to kin selection was a large paradigm shift. Kin selection wound up almost totally eclipsing group selection. Quantitative measurements of relatedness replaced fuzzy and often-inaccurate just-so stories about how some groups reproduced faster than other ones. In the organic realm this was a large displacement of poor quality science with better ideas that were more easily subject to quantification and testing. Group selection isn't exactly wrong - but kin selection carves nature at the joints - while group selection is more like chalk scraping on a blackboard. Regarding family members as promoting each others interests due to shared genes makes a lot of sense. Viewing families as consisting of partially-overlapping groups does not - because the "groups" involved are little more than mathematical abstractions. Kin selection was so obviously superior to group selection that the latter was relegated to the gutter as a tool for understanding the evolution of cooperation.

Cultural kin selection seems likely to result in a big boost to the meme's eye view. In the organic realm, the gene's eye view was often used to help visualize how kin selection worked. Similarly, in cultural evolution, it is often helpful to descend to the level of the meme to fully understand the dynamics of how cultural kin selection works.

Cultural kin selection helps to explain social cooperation. Understanding cooperation is important - partly because conflict can be so destructive. Cultural kin selection helps to explain our economic system, copyright law, our education system and how our military forces operate. It helps to explain why humans congregate in the groups that they do. As in the organic realm, cultural kin selection is tremendously important to a proper scientific understanding of the world.

Hamilton published on kin selection in 1964. Since it is 2014 at the time of writing, that was 50 years ago. This gives some indication of the scale of cultural evolution's scientific lag.