Response to Peter Richerson

A few comments on Peter Richerson's recent article: "Culture Is an ACTIVE Part of Biology". To start with a quote:

The specific idea that cultural variation can respond directly to selection, and then influence genes by the Baldwin Effect, is harder for many people to swallow. I reiterate that entertaining this idea is just to walk down Darwin’s straight and narrow path. It all boils down to heritable variation for fitness. Richard Dawkins followed this path in the Selfish Gene where he introduced the concept of memes. One of the problems with the meme concept as it evolved is that users of the term focused far too heavily on the selfish potential of memes. But I think it is near to undeniable that cultural variants are sometimes selected to become selfish patIthogens along the lines that Dawkins suggested.

Thumbs up to Richerson for endorsing memes!

It is true that meme enthusiasts typically focus on the down-side of memes. There is a reason for that. When meme-interests coincide with DNA-gene interests, it is not easy to tease them apart. So, to see where memes and DNA-genes differ, one must look for cases where there are fitness conflicts - where the two selective forces pull in different directions.

But then:

I don’t much care for the term “meme” for the same reason that Joe dislikes it. It implies a close analogy between genes and cultural variants.

Yes - there is a "close" relationship between genes and "cultural variants" - a.k.a. memes - for some value of "close". There are many similarities.

It also tends to imply that an inheritance system has to be quite gene-like to count as an entity that can behave in Darwinian ways. None of these things is necessarily true (Henrich et al., 2008).

"an inheritance system has to be quite gene-like to count as an entity that can behave in Darwinian ways" seems to be vague. The Henrich reference says:

Memeticists like Blackmore (1999) and Aunger (2002) believe cultural representations, or as they prefer, memes must be particulate for cumulative cultural change to occur.

Sue explicitly denies holding such a position in her review of Richerson's book Not By Genes Alone. Here's what she says:

The population approach, they say, does not imply that cultural evolution is analogous to genetic evolution; nor does it depend upon “discrete, faithfully replicating, genelike bits of information.” I quite agree, but then so would Dawkins and most other memeticists.

...and...

Nor do replicators have to be “discrete, faithfully replicating, genelike bits of information”. Dawkins long ago pointed out that the copying fidelity of most memes is very low, there is often no right way of deciding where one meme begins and another ends, and most memes do not appear to be particulate – themes later taken up by both Dennett (1995) and me (Blackmore 1999).

Epidemic threshold

The epidemic threshold refers to a threshold above which agents can spread explosively and cause epidemics. It is usually expressed in terms of the ratio between birth rate and death rate. If the ratio is larger than one, then an epidemic may result. If it is less than one then an epidemic becomes extremely unlikely.

The epidemic threshold is an important concept in epidemiology. It has previously been applied to cultural evolution - for example by Seth Godin in Unleashing the Ideavirus (p.77) - though he called it the magic-number.

Many factors influence the birth rates - including their level of virulence, their lifespan, whether they are defeated by attacks from the host immune system - and so on.

Being above the epidemic threshold does not guarantee that an epidemic will result. Statistical fluctuations may result in extinction before an epidemic forms. Being below the epidemic threshold makes an epidemic extremely unlikely, though.

The epidemic threshold is a pretty important idea in viral marketing. If your shareable item is below the threshold, and you get exponential decay - with negligibe viral effect. If it is above it, you could see exponential growth - as your marketing work is done for you by the masses.

Diagram

Epidemic failure and success.

This diagram shows the output from a very simple model of an epidemic. Infected hosts are plotted against time, from a fixed initial "seed" population. Different plot lines reflect different birth and death rates for the parasite.

Economic significance

The result of this is typically a non-linear R.O.I. on the marketing budget:

• Below the epidemic threshold the effects are so small that you might as well not have bothered.
  
• Above the epidemic threshold you see explosive growth - then it is more likely that the marketing budget has been well spent.

Much the same model applies equally well to mutualists as well as pathogens.

Big seed marketing

A related idea is big seeding - which is another strategy for avoiding extinction.

Tipping points

Malcom Gladwell once wrote a book called The Tipping Point - which referred to essentially the same concept. For more about that, see our post on that topic.

Note that the term epidemic threshold is also - rather confusingly - used to describe a number of hosts which need to be infected before an outbreak is classified as an epidemic. This post is not about that concept.

References

• How Viruses Spread
  
• Some simple epidemic models
  
• Discrete epidemic models
  
• Discussion: the Kermack-McKendrick epidemic threshold theorem
  
• The Kermack-McKendrick epidemic model revisited
  
• A threshold theorem for the general epidemic in discrete time
  
• Viral Math: R-Naught and Zarrella’s Hierarchy of Contagiousness

Memetic hijacking

Memetic hijacking involves a meme becoming active in a host and overriding the influence of its DNA-genes. The idea is named after the hijacking of vehicles - where an agent who is not supposed to be in charge siezes control.

The term applies to memes that are deleterious - from the perspective of host genes.

Just as viruses hijack host cells, so memes hijack host brains.

As with viral infections, memetic hijacking can be temporary or permanent. The host's memetic immune system can sometimes reassert itself, or the host can remain permanently infected - a persistent memetic infection.

Memes that are deleterious to their hosts lie on a spectrum between near-neutral hitchhikers to full-blown hijackers.

Examples

• Pornography - one of the more common and obvious sources of memetic hijacking;
• Cults - cults are rich sources of negative memes;
• Computer games - much computer game use appears to be memetic hijacking;
• Causes - a modern secular way for memes to take resources from human hosts;

Extreme cases of memetic hijacking can result in people infected with necrotrophic memes (sometimes called memeoids).

Search magnet

"Search magnet" is a conventional term in internet marketing. It refers to a co-meme which is effective at attracting the attention of those searching.

If using Hofstadter's terminology, a "search magnet" is a co-meme that attracts the attention of searchers to the scheme's bait. On the internet most searches are textual searches - so search magnets are often textual. Sometimes searches have a visual component - for example, where multiple items are presented to the user and they select one. So, we also have:

• Text search magnets - uses commonly-searched-for keywords;

• Image search magnets - looks visually interesting;

• Audio search magnets - sounds interesting;

Usually the prime function of the search magnet co-meme is to attract attention. However, it can do double duty - and be combined with the bait, or other co-memes.

Case studies

• Will it Blend is a classic use of search magnets.

  Blendtec's Will It Blend? viral videos combined many popular consumer electronics products with the Blendtec Total Blender in a novel way - by "blending" them. The show features the Blendtec founder, Tom Dickson, attempting to blend unusual items to help him show off the power of his blender.

  The full story is here - but for our purposes note that the result was a large number of short videos with names featuring popular consumer-electronics products.

  Dickson says that the campaign has been a great success for Blendtec:

  The videos were placed on the internet in early November. Within just a few short days, we had millions of views. The campaign took off almost instantly. We have definitely felt an impact in sales. Will it Blend has had an amazing impact to our commercial and our retail products.

• Another example of the use of search magnets is Ray William Johnson - an internet comedian who is best known for his stratgey of memetic hitchhiking on viral videos. His YouTube channel has details. Here is a sample video:

Missed opportunities

By contrast, the OldSpice YouTube channel is probably a failed example of a search magnet campaign. The campaign may have succeeded in other ways - but they made hundreds of videos, and did a really weak job of sprinking search-friendly keywords into the video titles.

Unleashing the Ideavirus (review)

My review of Seth Godin's book Unleashing the Ideavirus.

The tipping point

Physics

The idea of a tipping point is one that comes from physics. Adding a small amount of weight to a balanced object can cause it to suddenly and completely topple. The point at which it does so is known as the tipping point. References to the idea of a tipping point with reference to water buckets tipping over date back to the 1800s.

Chaos theory

Chaos theory has the closely-related concept of a catastrophe. This is dealt with by catastrophe theory. There is also the related concept of self-organised criticality. Before catastrophe theory came along catastrophes were treated as a form of runaway positive feedback.

Since chaos theory is so well established it would make a lot of sense to refer to "tipping points" as "catastrophe points" or "critical points". However, the term "catastrophe" has powerful and not always appropriate negative implications.

Sociology

The "tipping point" phrase was first applied in a sociological context by Morton Grodzins who studied American neighborhoods in the 1950s and 1960s. He discovered that most of the white families remained in the neighborhood as long as the comparative number of black families remained very small. But, at a certain point, when "one too many" black families arrived, the remaining white families would move out en masse in a process known as white flight. Inspired by the physics term, he referred to that moment the "tipping point".

Memetics

The term is a fairly general, but it appears to have an important application to memetics and cultural evolution.

The term is frequently applied with memes that "go critical". For viral content to explosively spread virally, people need to share it more frequently than they forget about it. For most wannabe-memes, they don't reach the required critical threshold - and are quickly forgotten about. However, other memes find themselves on the other side of the threshold - and spread virally - increasing in an exponential fashion. This effect is similar to what happens when a nuclear reaction goes critical. The critical threshold is now referred to as the epidemic threshold - a topic which I have a post about.

There are several possibilities here for memes to cross the threshold:

• Mutation - One is that your meme needs to mutate. An example of this would be the geddan meme - which had to cross the divide between video-game glitch and popular dance before making the big time.

• Hitchhiking - Another possibility is that it needs to find the right hitchhiking partner. An example of that is Keyboard Cat. The original keyboard cat video languished in obscurity - until it was used in a mashup by Brad O’Farrell - and then it exploded onto the internet - with thousands of copies being made, all of which used memetic hitchhiking with other viral content.

Memes can lie dormant for other reasons as well. Sometimes, they have not wandered into the right niche yet. Sometimes, they just need to find the right vector, who will get a proper infection started. Lastly, they may need environmental changes before they can thrive. Legal changes, changes in moral behaviour or the extinction of competing forms can all help a meme go over the tipping point.

One example of an environmental change is when there is a competitive shakeout in a contested market, usually leading to one winner. Initially the market is small, and several contenders aim to reap the rewards of dominating it. As time passes, one competitor draws ahead, and then users switch to their product or service in a rapid cascade.

We see this with VHS vs Betamax and HD-DVD vs Blu-ray, Facebook vs MySpace - and so on.

Malcom Gladwell's The Tipping Point

The idea of tipping points was popularised by Malcom Gladwell in his popular book, The Tipping Point - How Little Things Can Make a Big Difference.

Videos

Here's Meme Molly, explaining the The Tipping Point concept.

Here's a Guinness advert - illustrating Malcom Gladwell's point.

See also: Pot Noodle 'Tipping Pot' (Guinness Spoof)

References

• The Tipping Point - book - on Wikipedia
  
• The Tipping Point - sociology - Wikipedia
  
• Tipping Point Project - Durham university
  
• The Tipping Point - How Little Things Can Make a Big Difference
• The Influentials - One American in Ten Tells the Other Nine How to Vote, Where to Eat, and What to Buy

• The Tipping Point - on Malcom Gladwell's web site
• The Tipping Point's metaphorical windfall
• What's Plaguing Viral Marketing? - The Tipping Point Might Be More Myth Than Math - by Matthew Creamer
• There is no Tipping Point
• Is the Tipping Point Toast? - By Clive Thompson
• The Tipping Point - disambiguation page - Wikipedia
• Informational cascades - By Dan Zarella
• Information cascade - - on Wikipedia

Viral Video Chart

For internet meme enthusiasts, the Viral Video Chart offers a fine way of tracking trending YouTube videos.

It tracks shares of such videos on social media sites, and then builds lists of the most popular ones. There's also a search facility. It beats the native YouTube facilities in a number of areas. The site is well worth checking out if you not familiar with it - and are interested in viral videos.

URL: http://viralvideochart.com/. They also have a meme-blog and a social media blog.

Payloads and penetration

Following up on my description of Hofstadter's reduction of memeplexes into co-memes, I think we can identify some more useful co-memes.

To recap, Hofstadter proposed an interesting meme classification scheme, involving groups of memes known as schemes - which contain cooperating memes, which are now commonly called co-memes.

The common types of co-memes are usually considered to be:

• bait - attractive incentive to adopt the meme;
  
• hook - promoting replication - being "hooked" is all about passing it on;
  
• threat - of punishment, to assist hook execution;
  
• vaccime - innoculation to protect against rival memes.

I think this list can be usefully expanded upon.

Payload

Memetic hitchhiking notes that some kinds of content can be divided into two parts - a delivery mechanism, and a payload. The delivery mechanism contains all the elements designed to do the propagation, while the payload is the deliverable cargo - part whose transmission is the true purpose of the message. It is usually some form of advertising.

Penetration

In organic biology, pathogens often contain mechanisms designed to bypass host immune defenses. The malaria parasite uses a mosquito's hypodermic penetration equipment to get inside its host. Many other pathogens rely on being eaten by their hosts - since the body's defenses in the digestive tract are weaker. They work rather like Trojan horses. For example many flukes get past their host's defenses in this way.

In the domain of culture, schemes may contain elements designed to lower host memetic immunity before infection takes place.

"Trust us" is a simple example. "I'm on your side" and "let me help" work similarly.

Sometimes a one-two punch technique is used - first the host is softened up with emotional imagery, and then the target message is delivered. So, many religions have a history of using young ladies to make their converts. "Booth babes" are a more modern example of a similar technique.

Reducing host immunity seems to be a concept which is mostly distinct from Hofstadter's concept of bait.

Immunosuppression is the most common technical term for reduction in the effectiveness of the host's immune system. Immune evasion is the most common technical term for pathogens evading the host's immune system. I want an umbrella term that includes both types of technique. Immune penetration - or just penetration for short - seems to be the most suitable term to me.

Junk

Schemes may also contain free-riding memes and memetic junk.

Agner Fog in Cultural selection

Another classification scheme has been proposed by Agner Fog in Cultural selection (1999):

• Bait
• Hook
• Indoctrination
• Protection against rival meme complexes
• Reward and punishment
• Taxation

Meme alleles

Q: When is a meme not a meme?

A: When it is an allele!

In the organic world "gene" refers to a locus on a chromosome, and "allele" refers to particular genetic sequence that can occurs at that locus.

However, not many use the term "allele". People can't pronounce it. They can't spell it. They don't know what it means. So - most of the time - instead of using the word "allele" they just use the word "gene" instead.

Some aspects of the conceptual distinction between genes and alleles carries across into cultural evolution. So, the idea of there being certain "slots" with different mutually exclusive instances of heritable information that fit into those "slots" applies in both organic and cultural evolution.

To give a cultural example consider the idea of a furry feline animal. That represents a kind of "slot" into which "cat", "chat", "katze", "kat" or "gato" might fit - depending on which language you speak. The conceptual category of: word for a feline animal corresponds to a gene, and the specific word instances used correspond to alleles.

Words in languages behave like this, but there are other examples: preferred religion, favourite colour, choice of operating system, favourite food - and so on.

Famous examples of cultural alleles are: Pot-AY-to, pot-AR-to and tom-AY-to, tom-AR-to.

Now we get to the point of this post.

Most memes are less like genes than they are like alleles!

In common usage, if someone is talking about a meme, rarely are they talking about the idea of a "slot". Most of the time, they are talking about a particular instance - about somthing that fits into a "slot".

If you think people say "gene" when they really mean "allele" a lot, take heart. That is nothing compared to what happens in cultural evolution!

There, nobody ever says "allele" - and hardly anyone ever says "allomeme" or "meme instance". It is almost always "meme" instead.

So much for the gene-meme analogy: memes are more like alleles!

Memetic linkage

Genetic linkage refers to the concept that alleles in close proximity to each other have an increased chance of being inherited together.

The concept of linkage applies well in memetics too - leading to the idea of memetic linkage - which is the idea that nearby memes are more likely to be inherited together as a result of their close proximity.

To give some examples:

Adjacent sentences in documents tend to become linked together - and quotations may take adjacent sentences with them. Much the same thing happens with audio and video. Images may juxtapose unrelated subjects - which then become linked together.

For example, consider the girl standing in front of the CN tower. Or consider the aeroplane and the tourist in the images on the right. These days, the girl is often found with the tower, and the plane is often found with the tourist. Proximity-based linkage based on common descent is the primary reason for this.

Edward Burnett Tylor's adhesions

Edward Burnett Tylor laid the groundwork for the idea of memetic linkage in his concept of an `adhesion'.

Tylor was interested in cultural traits that appeared together, whether one trait caused the other, whether they were transmitted together, or what was happening.

Tylor presented his work on adhesions in a paper entitled:

“On a Method of Investigating the Development of Institutions; Applied to the Laws of Marriage and Descent,” which was published in volume XXVIII (1889) of the Anthropological Institute's Journal.

Tylor’s paper presented a method of “social arithmetic,” or statistical analysis of the presence of and “adhesions” between "traits". "Adhesions" broadly corresponded to correlations while the "traits" he considered were customs and institutions. He sought to compare traits with "adhesions" - to find those that seemed to occur together more frequently than the laws of chance would suggest.

The traits Tylor considered included in-law avoidance, post-marital residence rules, teknonymy, levirate marriage, couvade syndrome, bride kidnapping and exogamy.

Linkage-driven migration

An idea associated with the idea of genetic linkage is that alleles that have some kind of functional dependence on each other tend to migrate towards each other, so that linkage effects are increased, and the chances of them being divided from one another are smaller.

There are also other reasons that cause related ideas to clump together. That may mean that this effect may not be trivial to tease out experimentally.

Quantifying linkage

In genetics linkage can be quantified by measuring how far the linked alleles are from one another on a chromosome - or by looking at descendants and calculating the chances that the alleles are inherited together.

In memetics, the second option is still possible - memes frequencies can be tracked such as gene frequencies can - but a predictive theory based on the original heritable information itself is not so easy. Memes do not line up neatly in a one-dimensional space where distances from one another can be calculated easily. In podcasts and videos, temporal linkage may well be more significant than spatial linkage is. The linkage of a word to its neighbours depends little on whether the word is on one edge of the page. The linkage-distance between two memes is a more ambiguous concept than the linkage-distance between two genes. Instead you typically have to clearly specify what metric you are measuring memetic linkage with.

Criticism from Richard Dawkins

Richard Dawkins apparently denied the existence of "memetic linkage" in his 2005 book "The God Delusion". He said:

We doctors call that kind of linkage linkage, and I shall say no more about it because memes don't have chromosomes, alleles or sexual recombination.

However, he denied the existence of sexual memetic recombiantion in the same sentence - and that is surely an even more obvious concept.

Memetic linkage doesn't depend on memes being strung together in linear strings. The concept may be interpreted more loosely as an association - and then it becomes pretty clear that the idea does transfer across into the cultural realm. There is literature on "cultural linkage disequilibrium" - from Liane Gabora (1996). Memetic linkage disequilibrium is probably a better term, though.

Memetic hitchhiking

Memetic linkage is an important concept in helping to explain how memetic hitchhiking works.

References

• Liane Gabora (1996) A DAY IN THE LIFE OF A MEME
• Tim Tyler (2011) Memetic hitchhiking