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Memetic Scenarios for Evolving Cooperation

The main obstacle to the evolution of cooperation is the genetic competition between the cooperators: within a cooperating group the more selfish individuals stand to gain more from the cooperation, and thus are more likely to pass their "selfish" genes on to their offspring. Cultural or memetic evolution can sometimes subvert genetic injunctions, and we will argue more specifically that it will to some degree subvert this genetic tendency towards individual and familial selfishness.

Kin- and Group Selection for Memes

The genetic argument for altruism towards individuals carrying the same genes (kin selection) generalizes to altruism towards carriers of the same memes. Since memes can be passed between any two individuals, not just between parent and offspring, a meme can spread to a complete cultural group. The homogeneity of the group with respect to that meme then turns meme selection into a special form of "group selection", where the group is defined by all the carriers of a given meme.

The argument that group selection promotes cooperation remains valid: cooperating groups as a whole will be more fit than non-cooperating ones, and will tend to become larger, by higher reproduction rates or by "conquering" of, or imitation by, less successful groups. This is reinforced by the fact that cooperation tends to stimulate communication, and communication contributes to meme spreading and stabilization. Thus, memes that induce their carriers to cooperate will be more fit than those that don't.

Multiple Parenting Produces Conformity Pressure

On the other hand, the argument against group selection loses its validity for memes. The argument assumes that more selfish individuals profiting from the cooperation will pass their non-altruistic genes to their offspring. Memes, however, are not directly passed from parent to offspring, but from the complete group to individual members ("multiple parenting"). Majority memes will tend to dominate, eliminating competing (inconsistent) minority memes (Boyd & Richerson, 1985). This may be reinforced through some form of "moralistic aggression" (e.g. ostracism) towards non-conforming members of the group, which additionally diminishes their genetic fitness. Thus, memes for individual selfishness will find it very difficult to invade an altruistic group.

Memetic Interpretation of Tit-for-Tat

The above argument explains why once established cooperative memes will be consolidated by selection. It does not explain where cooperative memes might initially develop from. The "tit-for-tat" strategy, introduced in a genetic framework, can be easily reinterpreted as a meme, represented by the following set of condition-action pairs (*), or the decision network below:

This scheme is very simple to learn: use "cooperate" as a default initial condition, and further just mimic the behavior of the partner. If the partner uses the same scheme (or an even more altruistic one) a mutually beneficial cooperative relation will develop. If the partner defects, the exchange will stop before much harm is done. Such a cognitive strategy will therefore in general be beneficial to the partners, and thus be repeated. This means that others, observing the beneficial behavioral pattern, will tend to imitate it, taking over the cognitive scheme (*). That by definition makes (*) a meme.

From Tit-for-Tat to a System of Ethics

The difficulty with the above strategy lies in the recognition of the specific partner X. The strategy only pays off if one can distinguish partners and remember whether they cooperated or defected during the last encounter. Otherwise, every encounter is like a one-shot prisoner's dilemma, in which it pays to defect. In small groups, where interactions tend to be repeated often, a pure tit-for-tat strategy might flourish, as there would be little demands on memory. In larger groups, however, where many encounters happen for the first time, or are repeated only after a long interval in which the memory of the previous encounter might have faded, a different rule would be needed to avoid invasion by defectors.

As memes tend towards homogeneity within communicating groups (and towards heterogeneity between non-communicating groups), we might expect that after a while most members of a group G would follow the same general "tit-for-tat-like" strategy. It would then be more efficient not to distinguish between different individuals X1 or X2 in the group, but use the general rule of ingroup altruism:

if X belongs to group G, then cooperate

Whether X belongs to the group or not may be recognized by easily perceivable attributes, evolved by the group meme to facilitate distinguishing group members from members of other groups that carry different memes. "Thus the Luo of Kenya knock out two front teeth of their men, while the adjacent Kipsigis enlarge a hole pierced in their ears to a two-inch diameter" (Campbell, 1991). Since encounters with other groups will tend to be one-shot, it would pay to defect, and thus we could expect a complementary rule of outgroup hostility to evolve as a generalization of "defect from defectors":

if X does not belong to group G, then defect

Finally, the retaliation inherent in the original "tit-for-tat" strategy, as a means of protection against invading cheaters, would still be maintained in a rule of the moralistic aggression type:

if X belongs to group G and X defects, then punish X

What is considered "defection" will evolve to encompass gradually more diverse and complex patterns of behavior (e.g. lying, stealing, cheating, tresspassing rules, murdering, adultery, incest, etc.). Similary, the actions of "cooperate" and "punish" will differentiate into many different shades of behavior towards other members of the social system, dependent on the precise context. Finally, with the further spreading of related memes, what is counted as group G will tend to gradually broaden, encompassing individuals from other villages, other regions, other countries or ethnicities, until it would encompass the whole of humanity.


We have sketched a seemingly realistic scenario in which a meme complex derived from "tit-for-tat" may evolve step-by-step into an elaborate ethical and political system, capable to sustain an "ultrasocial" system as complicated as our present society. The difference between meme evolution and gene evolution (faster and more flexible adaptation, conformist and conversion selection criteria subverting genetic criteria) has allowed us to overcome the specific obstacles associated with "genetic competition among the cooperators".

Reference: Heylighen F. (1992) : "Selfish Memes and the Evolution of Cooperation", Journal of Ideas , Vol. 2, #4, pp 77-84.

Copyright© 1997 Principia Cybernetica - Referencing this page

F. Heylighen,

Mar 10, 1997


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Evolution of Cooperation

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