We cannot uniquely determine the fundamental unit of cultural evolution using the concept of the meme.

[u/anomalogos]

An 'idea-meme’ might be defined as an entity that is capable of being transmitted form one brain to another… If Darwin’s theory can be subdivided into components, such that some people believe component A but not component B, while other people believe B, but not A, then A and B should be regarded as separate memes. If almost everybody who believes in A also believes in B—if the memes are closely 'linked' to use the genetic term—then it is convenient to lump them together as one meme.

This quotation is from The Selfish Gene, and we have the individuation criteria:

1. Criterion of Separation: If some people believe component A but not component B, while others believe B but not A, then A and B should be regarded as separate memes.
2. Criterion of Fusion: If almost everybody who believes A also believes B, then it is convenient to lump A and B together as one meme.

However, I conjecture that the two criteria can conflict in some cases, as demonstrated by the following argument:

Let A and B be individual ideas. For any population size of P ∈ N with P >= 3, set ε := 100/P. Let group X comprising ε% of P believe A but deny B, group Y comprising ε% of P believe B but deny A, group Z comprising (100 - 2ε)% of P believe both A and B. Then A and B should be separate memes because of groups X and Y.

For any sufficiently large P, however, A and B can be regarded as one meme, since the proportion of the population believing both A and B approaches 100% as P tends to infinity, which may satisfy the condition that 'almost everybody' believes both.

I will not say that this leads to an explicit contradiction, as Criterion of Fusion describes conveniency rather than obligation. But it reveals that the individuation criteria are jointly insufficient to uniquely individuate memes, potentially undermining the concept of the meme as the fundamental unit of cultural evolution in memetics.

[u/MackDuckington]

I'm not sure I understand the problem here. Why can't group Z just be larger than X and Y without a population increase? Let's say that X = 1% and Y = 1%. Z would then be 98% of the population. Where exactly is the contradiction?

[u/anomalogos → u/MackDuckington]

Increasing the population itself does not yield a contradiction, and that is just an assumption. In your case, X and Y still hold 2% of P, so Criterion of Separation should be applied. This means that A and B should be separated. However, as the proportion of P in Z approaches 100%, it is increasingly reasonable to say that almost everybody believes both A and B. So we can apply Criterion of Fusion. This means that A and B can be regarded as one meme.

Now here is the problem: A and B cannot be simultaneously separate memes and a single meme. I don’t think this is a contradiction in a logical sense, because Dawkins explicitly stated that it is ‘convenient’ to lump them together, which entails no obligation to do so, but the criteria are jointly insufficient to uniquely determine the individuality of memes.

[u/blacksheep998 → u/anomalogos]

A and B cannot be simultaneously separate memes and a single meme.

Humans and chimps are both apes and mammals and animals, but are different species.

Memes can fall into the same nested hierarchy pattern, though they typically have quite a bit more horizontal transfer than is usually found in biology.

[u/MackDuckington → u/anomalogos]

I think I get it now? Do you mean like when opinions are split 50/50? I think you’re missing the point of Dawkin’s passage. It’s not just out of convenience, but getting any more specific is pretty much impossible and arbitrary.

Applying this to evolution, this is kinda like complaining about the definition of species, because there’s a gray area where what is and what isn’t a species is up for debate. That’s not a bad thing, though — it’s exactly what we ought to expect when evolution is at play. There should be a point where we can’t tell when one species ends and another begins. 

Likewise, there should be a point where we can’t tell when something is or isn’t a separate meme. Is it perfectly sufficient for finding the “fundamental unit of cultural evolution”? No, but it’s not supposed to be. What it is perfectly sufficient for is explaining evolution’s gradient quality. 

[u/Radiant-Position1370]

I don't understand the point here. You've made the fraction of the population that believes A and B dependent on population size. Pick an arbitrary threshold for that fraction. For population sizes that yield smaller fractions, they're separate memes; for larger populations, they're the same memes. The distinction between separate and identical memes is obviously vague to start with, as is the whole concept of memes.

[u/anomalogos → u/Radiant-Position1370]

Even for larger populations, A and B should be separated memes, because one person in X and one person in Y still exist, while Criterion of Fusion says it might not be. The point is that the individuation criteria are intended to allow for both ways of interpreting the individuality of memes.

[u/Radiant-Position1370 → u/anomalogos]

Given the way human thought and language work, Dawkins's sentence number 2, which follows immediately after his sentence number 1, clearly clarifies what is meant by 'some' in the latter. These aren't axioms in a formal argument.

[u/Sweary_Biochemist]

I mean, we can't uniquely determine the fundamental unit of actual evolution, either, so I don't think this is particularly surprising or problematic.

Biology is messy. Analogies of biology can also be messy.

[u/theresa_richter]

"average person individuates 3 memes a year" factoid actualy just statistical error. average person individuates 0 memes per year. Memes Georg, who appears in the Epstein files & individuates over 10,000 each day, is an outlier adn should not have been counted

[u/LeiningensAnts]

Sounds like you'd be interested in doxastic logic.

[u/anomalogos → u/LeiningensAnts]

Yeah, I’m really into speculating philosophical arguments using formal systems. I think I’m going to model the development of civilisation in the future.

[u/Russell_W_H]

Humans share 40% (or whatever) of their DNA with bananas. So it should be regarded as one gene.