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Date: Mon, 13 Jul 1998 16:34:27 +0100
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BASIC QUESTIONS IN MEMETICS:
LIFE-CYCLE, REPRODUCTION AND RESOURCES

Szabolcs Szamado


Eotvos Lorand University
Department of Plant Taxonomy and Ecology
Hungary, Budapest, Ludovika tér 2, H-1083


1. Introduction

	The basic understanding of any organism starts with the description of 
its morphology, environment, behaviour and its life-cycle by which it 
propagates itself. Memes are no exceptions. Although various studies have 
addressed these basic questions (Ball, 1984; Gabora, 1996; Pocklin
gton, 1997; Lynch, 1998) and, of course, most major work about cultural 
evolution has something to say about it (Dawkins, 1976; Boyd & Richerson, 1982; 
Lumdsen & Wilson, 1982), there is still no general conclusion, and there is 
still no general terminology. The lack of a proper description of the memetic 
life-cycle is especially disturbing since in its absence it is hard to evaluate 
the weight of different selective forces, it is hard to build any mathematical 
model concerning meme population-dynamics or de
mography and it is hard to decide the importance of different kind of 
resources. The aim of the present paper is to give a detailed description of 
the memetic life-cycle and to investigate some of its consequences. 
	The structure of the article is as follows. In the second section basic 
definitions for life, replicators, and interactors are proposed. In section 3 a 
model of memetic reproduction and life-cycle is presented. The main assumptions 
of the model are discussed in the next section. Section 5 exam
ines the nature of necessary and sufficient resources for memetic reproduction. 
Section 6 lists the main properties of memes from a modelling point of view. 
Finally, section 7 concludes. 

2. Replicators, interactors and the definition of life

	To build a logical model we should have logical and clear-cut 
definitions. Moreover, the nature of the definitions should depend on the 
problem which we want to attack. From a population biological point of view any 
definition of replicators and interactors shou
ld enable us to decide between life and death, between living systems and 
reproductive vehicles and should enable us to tell whether an entity under 
question is a replicator an interactor or both.
	Living systems have two major properties: 
(1,) First, they are all non-equilibrium open systems (Maynard Smith, 1986; 
Szathmáry, 1989) with an inherent stability, which is maintained by self-
regulating processes (Gánti, 1987). That means that there is an energy and 
substrate flow between the organism and the e
nvironment, and the organism is on a higher energetic state than its 
surrounding, moreover, this higher state needs and active maintenance via 
energetic input. In other words, a living organism increases the entropy of its 
environment in order to maintain its own state of low entropy. With Schrödinger 
words: organisms live by 'eating negative entropy'. 
(2,) Third, they are all capable to evolve (Maynard Smith, 1986). That follows 
from the fact that they are all results of evolution by means of natural sel
ection. Thus, every living system has the property of self-reproduction, 
heredity and variation.
	With these two major properties in mind we want to create a definition 
which, on the one hand, excludes every non-equilibrium system which is not a 
living one (such as fires or whirls (Maynard Smith, 1986)), and on the other 
hand, excludes every self-replicating system which is not a living one (such as 
certain crystals, for instance silicates (Szathmáry, 1984)).

	The classical definitions of replicator and
 interactor by Hull (1988) are as follows:
	A replicator is 'an entity that passes on its structure largely intact 
through successive replications.'
	An interactor is 'an entity that interacts as a cohesive whole with its 
environment in such way that this interaction causes replication to be 
differential.'
	
	With our requirements in mind I propose the following definition, first 
for living systems in general:
(Definition 1.) 'A self-replicating non-equilibrium open system with inherent 
unity and stabi
lity, capable to evolve.'
Second, we want to define interactors as living systems so the following 
definition can be proposed:
(Definition 2.) 'A non-equilibrium open system with inherent unity and 
stability, which interacts with the environment and with other interactors in 
order to create and maintain the conditions for some replicator to replicate.'
With this definition I want to emphasise that interactors are living systems, 
and that their function is to create and maintain sufficient conditions for 
replicators to replicate. Differential reproduction is not an essential 
property, it is just the result of the fact that different interactors are 
coded by different replicators. 
Finally, I think that Hull's definition for replicators is correct so I want to 
give a loose and a strict definition only for living replicators. The broad 
definition is as follows: 
(Definition 3.) ' A living replicator is a replicator which is either itself an 
interactor or it is a part of an interactor.' 
This definition can
 help us to decide whether a gene, a meme, a virus, or a computer virus is a 
living replicator or not. For instance, one of the most subtle problems of 
biology whether a virus is a living organism or not. I argue that if it is 
within the host cell then it is as living as any other DNA in that cell. But 
what about virions outside cells? And what about other reproductive vehicles, 
such as seeds, pollens, eggs and so on? I will discuss this problem a little 
bit later. First, let us see the strict definition. A
ccording to this: 
(Definition 4.) 'A living replicator is a replicator which is either itself an 
interactor or it is a part of an interactor and capable of creating and 
maintaining a lineage of interactors through geological times.' 
This definition helps us to make the difference between dependent and 
independent replicators. Any independent replicator should fit the above 
definition. Currently we know only one type of them: the genes. All other 
replicators (memes, viruses, computer viruses) do not fit 
this definition, they are all dependent on the interactors coded by the genes. 

	Finally, the concept of phenotype is defined as:
(Definition 5.) 'A trait, a behaviour or a tool by which an interactor 
interacts with its environment or with other intaractors.' 

3. The life-cycle of memetic reproduction

	In order to describe the life-cycle of memetic reproduction first we 
should decide what is a meme. Although it is intuitively easy to understand, 
creating an exact definition has challenged the fiel
d of memetics up to the hilt. For the purpose of the present model Dawkins' 
original definition will suffice (1976). That is, a meme is a unit of cultural 
transmission, a replicator which has the properties of replication, heredity 
and variability. To depict a life-cycle, however, we should go a little bit 
further and we should ask that what counts as a living meme? Is an article, a 
book, a film, a song, a clothes a living meme or only those memes represented 
in human brains should be counted among the livi
ng ones? I vote for this latter possibility and later on I will discuss it in 
more detail. I argue that the former ones are just reproductive transmitting 
vehicles (RTV-s) and a formal analogy with viruses exists from this respect. 
There is a difference however, memes can be transmitted either directly or 
indirectly. The direct transmission is from human to human and can make use of 
the entire repertoire of human communication: language, gestures, body contact, 
etc. The indirect one takes the form of human 
- transmitting vehicle - human, where a transmitting vehicle can be anything 
ranging from stones, wood, paper and other materials to TV, radio, phones, or 
computer nets. To complete the description of the life-cycle, the phenotype - 
memotype relation should be discussed. It is a widely accepted assumption that 
memes behave similarly from this respect to genes, that is, they cannot be 
selected directly, instead they code for some phenotypic trait which, 
interacting with the environment and with other organis
ms will determine the reproductive success of that particular meme (Ball, 1984, 
Wilkins, 1998). That is, memetic reproduction fits in the scheme of generalised 
selective processes depicted as generate - test - regenerate cycles (Plotkin, 
1994, Wilkins, 1998). I argue that this is not the case. The reproductive 
success of memes are not linked to their phenotypes and that some memes have no 
phenotype at all! Sure enough, a successful phenotype can enhance the meme 
reproductive success but its not a necessary 
condition. What counts is the meme relation to other memes. 
 Based on these assumptions the following general model for a memetic life-
cycle can be proposed (Fig.1.). An active meme (M) lives in its host organism, 
in an infected human brain (IHB). It can reproduce either directly (DT) via 
human communication or indirectly (IT) via transmitting vehicles (RTV). The aim 
of the transmission and the criteria of success is to infect an uninfected 
human individual (UHB). Both direct and indirect transmission can
 be influenced (dashed lines) by the meme's phenotype (PH), it can increase or 
decrease it but its existence is not a necessary condition for reproduction. 
Sometimes, however, even the phenotype can transmit the meme (songs, gestures). 
This form of reproduction is called as phenotypic transmission (PT).

Figure.1. The memetic life-cycle. See explanation in the text.4. The main 
assumptions of the model	First, we should discuss the problem whether memes 
in books, films, journals should be counted as l
iving memes or that living memes must reside in the brains of (living) humans. 
Some argues that living memes can exist outside of a human brain (Wilkins, 
1998), however, I have already indicated I vote for the opposite case. The 
argument is as follows. First, books, pictures or tapes are not interactors 
(Def.2.). They are not non-equilibrium open systems, and they cannot interact 
actively with their environment. Only humans are interactors. Second, living 
replicators have to reside in interactors (Def.3.). 
Hence memes have to reside in human brains in order to be counted as living 
ones. One can argue that memes are interactors themselves. That is true but 
they can only interact with each other in human brains. Two books cannot 
interact with each other (unless you put one on the top of other) neither can 
two articles in the same journal. But then what is the status of the memes in a 
newspaper or in a book? They are not living ones but certainly they are not 
dead. Now, we can recall the problem of viruses and b
iological reproductive vehicles such as seeds or eggs. I have argued in the 
previous section that books and films and radio programs have the same status, 
they are memetic reproductive vehicles (RTV-s). So the question is the same. Is 
an egg, a pollen, a seed, a book, or a film contains a living replicator or 
not? The answer is yes and no at the same time. We cannot tell. The problem is 
similar to that of Schrödinger's cat. Until you open the box you cannot tell 
whether the cat is dead or alive. Until you t
ry to germinate a seed or incubate an egg you cannot tell whether any of them 
are living or not. Each egg, each seed has a potential to develop into a living 
organism, but that is just a potential. The only thing one can say is the 
probability of germination or hatching. The situation is similar with memetic 
reproductive vehicles. One cannot tell whether a book or a newspaper contains a 
living meme or a dead one. The only thing one can tell is the probability of 
infection if a human reads them. This approac
h may seem to be a strange one but its certainly not a new one. It is widely 
applied, just for to the other end of the living dead continuum. If someone 
finds an ancient writing what is the way to find out whether it is written in a 
dead language or in a living one? The finder probably shows it to a lot of 
people and if no one understands (that is, the meme written in that language is 
unable to infect any people) then the language is declared to be dead.  
	Next, the problem of the phenotype should be disc
ussed. I argue that the widely accepted analogy with genes (Ball, 1984; 
Wilkins, 1998), i.e. memes should have phenotypes and they are selected upon 
it, is false. Memes need not have phenotypes. Have you ever seen the phenotype 
of God? In theory three types of meme can be distinguished. Memes which always 
express their phenotypes, memes which sometimes express their phenotypes, and 
memes which have no phenotypes at all. For the first class human gestures can 
be cited as examples, provided they reproduce by 
imitation. The vast majority of the human memes falls into the second category. 
Finally, our abstract ideas and notions such as God, freedom, right and wrong 
are examples for the last type of memes. To highlight the second class, let us 
take the example of scientific theories. One would think that a scientific 
theory surely have to have a phenotype otherwise what is the use of it? Note, 
however, that any theory first should infect at least some person (the 
influential the better) in order to gain access to 
the resources which are necessary to produce the phenotype of the given theory. 
Second, theories are not evaluated solely on the basis of their phenotypes, 
i.e. on their success or failure to predict certain kind of observable 
phenomena, but rather frequently on the basis of meme relations. For instance, 
the theory of socio-biology was accepted or refused in the USA usually on the 
basis of ideological motivations, or the theory of the inheritance of acquired 
characters spread in the Soviet Union for politic
al reasons in spite of the contradicting evidence. 



5. Memetic resources

	The present model helps us to differentiate between various memetic 
resources. That on turn can serve as a basis for a memetic niche definition 
(Számadó, forthcoming). Since active memes must reside in the brains of humans 
the primary resource for memetic reproduction is the human brain. Direct 
transmission does not requires any extra resource. Reproductive (or secondary) 
resources are the necessary inputs for the production
 of reproductive transmitting vehicles (RTV-s), i.e. for indirect transmission. 
Finally, the phenotypic (or tertiary) resources are those which are required to 
produce the memes phenotype. As we have seen from the previous section only the 
primary resource is necessary for successful reproduction. The presence or 
absence of secondary and tertiary resources, i.e. the production of RTV-s or 
the phenotype can enhance the success of a meme but not a necessary condition 
for reproduction. Finally, there is a four
th kind of resource. That is the computational time of the human brain 
(Dawkins, 1976).
	Science is an appropriate example for this classification. Since the 
human brain is the primary resource of memetic reproduction, the observation 
that PhD. students are the most prized resources is not surprising at all 
(Wilkins, 1998). Publication space in scientific journals, proceedings, books 
are secondary resources, and labs, grants and other equipment are tertiary 
resources. 

6. Basic properties of memes

	O
n the basis of the present scheme it is possible to classify the most important 
properties of a meme from a modelling point of view. 
The meme as a replicator has three widely accepted properties:
Survival: how long it can persist in a brain of a human.
Copying fidelity: the precision of the copying process.
Reproductive activity: either direct or indirect reproductive attempts per unit 
time.

The meme as an interactor has two (rather descriptive) properties:
Popularity: it shows how attractive or re
pulsive the meme for a given other meme.
Tolerance: it shows how attractive or repulsive are the other memes from the 
point of view of the investigated one.
Basically, the popularity and the tolerance are the two sides of the same coin. 
These relations can be best represented in a matrix form, when each row gives 
the tolerance values of a meme to others and each column tells how other memes 
like the meme under question. There are zero values in the main diagonal.

The process of indirect reproduction ha
s the following properties:
Fundamental potential: it shows that how successfully can a given meme infect 
peoples in the form of the given RTV (which crucially depends on the popularity 
of the meme among the already presented memes found in the uninfected human 
brain).
Realised potential: how much proportion of the fundamental potential is 
realised.
For instance, the fundamental potential gives how many people can remember to 
the meme provided he/she have read it in the journal, have seen it on the TV, e
tc. But obviously, not every one has read that journal or has seen the given 
program on TV, so the realised potential shows that actually how many people 
have read that journal, have seen that TV program, etc. and can remember to the 
meme.

The process of direct reproduction has the property of:
Efficiency: which tells the proportion of successful infections as a result of 
direct transmission (which is also depends on the popularity of the meme). 

Finally, a meme can have phenotypic properties by whic
h it can modify both its own or any other meme's any properties, or any encoded 
properties of any other kind of replicators (genes). 


7. Conclusions

	The present model depicts a scheme of a general memetic reproduction. It 
helps us to tell the difference between living and dead replicators, between 
interactors and reproductive transmitting vehicles. Most of the problems of the 
field arise from the  confusion of living memes or phenotypes of memes with 
RTV-s which can be traced back to Dawkins (1976)
. For example, a plan of car in a human brain is the living meme, a plan on the 
drawing board is an RTV, and finally, the car is the phenotype. If one reads a 
book and remembers it then the story in her/his brain is the meme. The book, 
however, is not the phenotype! It is only an RTV. In a similar way: a mail on 
the Internet is not a meme (Pocklington, 1997; Best, 1997), neither a meme 
relics (Lynch, 1997) or a phenotype (Dawkins, 1982), it is an RTV. Sometimes, 
however, the phenotype can transmit the meme 
(songs, gestures). This possibility was realised by Denett (1995) and he called 
the transmitting objects as "meme vehicles". However, it is important even in 
this case to differentiate between the phenotype and between the RTV-s. Both 
may transmit the meme, but that is the RTV's only function which does not hold 
for the phenotype. Furthermore, the model allows to differentiate between the 
primary, secondary (reproductive) and tertiary (phenotypic) resources. Finally, 
it describes the main properties of a me
me which should be taken into account in a population dynamical or 
demographical model. For example, it shows that if someone measures  the daily 
frequency of a given type of a mail on the Internet (Pocklington, 1997; Best, 
1997) it gives only the reproductive activity of that given meme (i.e. how many 
RTV-s (mails) does it produce during a day) and not the reproductive rate (i.e. 
how many mature offspring was produced).

I thank to Eors Szathmary and Istvan Scheuring for helpful comments and 
discussion. 
This work was supported by the Pal Juhasz-Nagy junior-fellowship of Collegium 
Budapest.



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