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.
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
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.
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
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 (*)
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
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.