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Ch. 5 - Aggression: stability and the selfish machine

Posted: Sun Aug 02, 2009 1:49 am
by Chris OConnor
The Selfish Gene by Richard Dawkins
Ch. 5 - Aggression: stability and the selfish machine

Posted: Tue Sep 15, 2009 9:14 pm
by Robert Tulip
Chapter Five introduces Game Theory as the basis for analysis of evolutionary stable strategies. ESS is the tendency of populations to evolve towards an equilibrium such that alternative behaviour strategies (eg hawk/dove) are in line with the long term economics of cost and benefit for their genes. Looking at five strategies – hawk, dove, retaliator, bully and prober-retaliator, Dawkins says “in a computer simulation, only one of them, retaliator, emerges as evolutionarily stable. Dove is not stable, because a population of doves would be invaded by hawks and bullies. Hawk is not stable, because a population of hawks would be invaded by doves and bullies. … In a population of retaliators, no other strategy would invade.” (p80)

What this makes me wonder is how this use of Game Theory for genetics could also be used for memetics. The example I am thinking of is the influences governing the change in population of atheists and believers. If we can start to tot up the costs and benefits of the alternative strategies of atheism and Christian belief, they might look like the following

Atheism
Benefits: better health, income and relationships through reliance on evidence and logic;
Costs: Disapproval of Christians

Christianity
Benefits: Social inclusion and cohesion;
Costs: Falsity of main ideas leading to disapproval of atheists and decisions that conflict with evidence

I’m wondering, could we add to this list and assign values to the benefits and costs to start examining what factors govern the rise and fall of such cultural memeplexes?

I found the following Chapter Five Summary from the Selfish Gene Wikipedia
Chapter 5 - Aggression: stability and the selfish machine
To a survival machine, another survival machine (which is not its own child or another close relative) is part of its environment, like a rock or a river or a lump of food. It is something that gets in the way, or something that can be exploited. It differs from a rock or a river in one important respect: it is inclined to hit back. This is because it too is a machine that holds its immortal genes in trust for the future, and it too will stop at nothing to preserve them. Natural selection favours genes that control their survival machines in such a way that they make the best use of their environment. This includes making the best use of other survival machines, both of the same and of different species.
This interpretation of animal aggression as being restrained and formal can be disputed. In particular, it is certainly wrong to condemn poor old Homo Sapiens as the only species to kill his own kind, the only inheritor of the mark of Cain, and similar melodramatic charges.
If only everybody would agree to be a dove, every single individual would benefit. By simple group selection, any group in which all individuals mutually agree to be doves would be far more successful than a rival group sitting at the ESS (Evolutionary Stable Strategy) ratio.... Group selection theory would therefore predict a tendency to evolve towards an all-dove conspiracy... But the trouble with conspiracies, even those that are to everybody's advantage in the long run, is that they are open to abuse. It is true that everybody does better in an all-dove group than he would in an ESS group. But unfortunately, in conspiracies of doves, a single hawk does so extremely well that nothing could stop the evolution of hawks. The conspiracy is therefore bound to be broken by treachery from within. An ESS is stable, not because it is particularly good for the individuals participating in it, but simply because it is immune to treachery from within.
But there are other ways in which the interests of individuals from different species conflict very sharply. For instance a lion wants to eat an antelope's body, but the antelope has very different plans for its body. This is not normally regarded as competition for a resource, but logically it is hard to see why not. The resource in question is meat. The lion genes 'want' the meat as food for their survival machine. The antelope genes want the meat as working muscle and organs for their survival machine. These two uses for the meat are mutually incompatible, therefore there is conflict of interest.

Posted: Thu Sep 17, 2009 6:51 pm
by DWill
This chapter raises awareness that there seems to be no behavioral trait considered in isolation that could be can be labelled maladaptive as far as survival is concerned. Whether the trait would persist in a population would depend on whether it teamed with traits shown by other individuals to form an ESS. Meekness, for example, can then be a trait that continues to be selected, because it works in a mix with boldness. This might not be intuitive for us because we think of survival in terms of the dominance of individuals.

Regarding the memetics part of your post Robert, well, is this a tool that is really adequate for such a project as you propose? I'm struck by the tentativeness of Dawkins' offering of memes, which even amounts to backpedaling in the notes to Chapter 11. He says that memes have "really nothing to do with genetic evolution." (p. 190) and that with the meme theory "my designs on human culture were modest almost to the vanishing point." (p.322) Has Dawkins written further about memes since this book? I need to look into to that. I suspect that memes are relevant only in terms of greasing the skids for certain cultural phenomena, making them catch on more readily, but are not tools that enable us to probe deeply. Interestingly, the word 'memetics' itself illustrates this effect of acceleration. Dawkins used the term 'memics' in his endnotes, appropriately for a concept that "has nothing to do with genetic evolution." Others came along and, wanting to emphasize a similarity to genetics, adopted the rhyming 'memetics.' It's not far-fetched to think that this strong association with a credible science greased the skids for the idea, giving it more momentum than 'memics' would have had. We don't, however, need new jargon to explain this kind of thing.

Fundamentally, I think it's a mistake to say that the influencing of one human by another is a process of transmitting copies. There is an idea of human nature behind this that is neither accurate nor appealing. Thanks for hearing this.

Posted: Sat Sep 19, 2009 1:42 pm
by geo
Thanks again for the summary, Robert.

For me this chapter really solidifies some of the concepts from Ch. 2, The Replicators, how individual entities in a complex environment (system) naturally gravitate towards stability without any kind of guiding force except by virtue of the fact that stable things will tend to outlast unstable things.

Here, from Ch. 2, is Dawkins' speculative vision of the primordial soup out of which arose the first life:

"If a group of atoms in the presence of energy falls into a stable pattern it will tend to stay that way. The earliest form of natural selection was simply a selection of stable forms and a rejection of unstable ones. There is no mystery in this. It had to happen by definition." (pg. 13)

and later . . .

". . . when the replicators became more numerous, building blocks must have been used up at such a rate that they became a scarce and precious resource. Different varieties or strains of replicator must have competed for them. . . . There was a struggle for existence among replicator varieties. They did not know they were struggling, or worry about it; the struggle was carried out without hard feelings , indeed without feelings of any kind. But they were struggling, in the sense that any mis-copying that resulted in a new higher level of stability, or a new way of reducing the stability of rivals, was automatically preserved and multiplied. . . . The replicators that survived were the ones that built survival machines for themselves to live in. The first survival machines probably consisted of nothing more than a protective coat. But making a living got steadily harder as new arrivals arose with better and more efficient survival machines. Survival machines got bigger and more elaborate, and the process was cumulative and progressive." (pg. 19)

Fast forward billions of years and we see the same kind of thing going on only on an individual survival machine basis. With gaming theory we see that everything is becoming incredibly fine-tuned. It has to be because resources are limited and the survival machines are in competition with each other. Only the most efficient organisms are going to survive. And just as the group of atoms tends to fall into stable pattern so does the way individual organisms compete with one another by falling into evolutionarily stable strategies.

The ones that survive do so because that's how it comes out in the wash, meaning these various strategies start out fairly randomly, but after awhile only the ones that consistently work remain. Fascinating stuff here.

Regarding Robert's idea to look at gaming theory for memes, I'm still not far enough in the book to do that.