Chapter Chapter-by-Chapter Anaylsis of The Selfish Gene (1989 edition) - Study Guide by Richard Dawkins

To explain this, he returns to first principles. He argues that what is true of all life, wherever it is found and whatever the basis of its chemistry is, is that "all life evolves by the differential survival of replicating entities". Up to this point in his book, he has argued that the gene, the DNA molecule, is the only replicating entity on our planet, but now he introduces the possibility of a new type of replicator that has emerged.

Using the analogy of the primeval soup of DNA molecules, he suggests that there is a new soup, the soup of human culture, and the individual units in this soup he calls memes. He believes that by making brains for their survival machines, the traditional gene-selected evolution provided this "soup" in which the first memes arose. Examples of memes are tunes, ideas, catch phrases, and clothes fashions. He argues that "just as genes propagate themselves in the gene pool by leaping from body to body via sperm or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process, which in the broad sense, can be called imitation".

For example, if a scientist hears or reads about a good idea, he may pass it on to his colleagues and he may mention it in his articles and lectures. If the idea catches on, it can be said to propagate itself, spreading from brain to brain. And just as with gene evolution, some memes are more successful in the meme pool than others. This will depend on the meme’s longevity, fecundity and copying fidelity.

He pursues the analogy between memes and genes further by asking if it is possible to have selfish or ruthless memes? The difference here between genes and memes concerns the nature of competition, because memes do not have the equivalent to chromosomes or alleles. However, he argues that memes do have an alternative form of competition over memory storage space in the brain and time spent being attended to. If a meme is to dominate the attention of a human brain, it must do so at the expense of "rival" memes because the human brain cannot do more than one or a few things at once.

Therefore, he concludes that cultural traits have evolved because they are advantageous to themselves, and not because they are advantageous to the genes (or the individual, the group or the species). He emphasises that DNA molecules are not the only entities that can form the basis for Darwinian evolution, and that any slight inaccurate self-replicating entity can become the basis for such selection if given the right conditions and enough generations.

Nice guys finish first

Axelrod and Hamilton (1981) used game theory and the concept of an evolutionary stable strategy (ESS) to develop a model of evolution of co-operation based on reciprocity. They used the Prisoner’s Dilemma game to solve the problem of achieving co-operation, mainly concentrating on the two-player version of the game which describes situations that involve the interactions between pairs of individuals. In the Prisoner’s Dilemma game, two individuals can each either cooperate or defect. No matter what the other does, the selfish choice of defection yields a higher payoff than co-operation. But if both defect, both do worse than if both had co-operated. The payoff matrix of the Prisoner’s Dilemma can be seen below:

		PLAYER B
		Co-operate	Defect
PLAYER A	Co-operate	R = 3 Reward for mutual Co-operation