The survival value of successful competition is almost an axiom of evolutionary theory. Why,
then, has cooperation survived evolutionary pressure, in humans as well as in many other species?
Kinship theory is the usual explanation. According to kinship theory, a genetically influenced strategy such as cooperation is evolutionarily viable if it helps a substantial portion of one’s gene pool
to survive and reproduce, even if the cooperator dies. A classic example is the sterile worker honeybee, which commits suicide by stinging. Altruism of parents for offspring is easy to explain, but
kinship theory also successfully predicts that altruism would be high among all members of an immediate family and present throughout an inbred tribe. Sacrifice for an unrelated tribe member may
improve future treatment of one’s children by tribe members.
Modified kinship theory can account for many manifestations of cooperation and competition among scientists. An us/them perspective can be developed among members of a company, university, or research group. Thus a member of a National Science Foundation proposal-review panel must leave the room whenever a proposal from their home institution is under discussion. Here the health or reputation of an institution is an analogue for genetic survival. Similarly, a clique of scientists with the same opinion on a scientific issue may cooperate to help defeat a competing theory.
For scientists facing the decision of cooperation or competition with a fellow scientist, kinship theory is not a particularly useful guide. A more helpful perspective is provided by the concept of an evolutionarily stable cooperation/competition strategy. Evolution of a cooperation/competition strategy, like other genetic and behavioral evolutions, is successful only if it fulfills three conditions [Axelrod and Hamilton, 1981]:
• initial viability. The strategy must be able to begin by gaining an initial foothold against established strategies.
• robustness. Once established, the strategy must be able to survive repeated encounters with many other types of strategy.
• stability. Once established, the strategy must be able to resist encroachment by any new strategy.
Axelrod and Hamilton [1981] evaluated these three criteria for many potential cooperative/competitive strategies by means of the simple game of Prisoner’s Dilemma [Rapoport and Chammah, 1965]. At each play of the game, two players simultaneously choose whether to cooperate or defect. Both players’ payoffs depend on comparison of their responses:
My choice Other’s choice My score Explanation cooperate defect 0 Sucker’s disadvantage defect defect 1 No-win mutual defection cooperate cooperate 3 Reward for mutual cooperation defect cooperate 5 Competitive advantage
When the game ends after a certain number of plays (e.g., 200), one wants to have a higher score than the opponent. But even more crucial if the game is to be an analogue for real-life competition and cooperation, one seeks the highest average score of round-robin games among many individuals with potentially varied strategies.
The optimum strategy in Prisoner’s Dilemma depends on both the score assignments and the number of plays against each opponent. The conclusions below hold as long as:
• S < N < R < C, i.e., my defection pays more than cooperation on any one encounter, and cooperation by the opponent pays more to me than his or her defection does;
