Algorithm

Cognitive psychology

Process (computing)

Philosophy

Social dilemma

Microeconomics

Social psychology

Vitality

Operating system

Economics

Computer science

Protocol (science)

Imitation

Superrationality

Prisoner's dilemma

Alternative medicine

Psychology

Dilemma

Repeated game

Mathematics

Epistemology

Geometry

Medicine

Game theory

Theology

Knowledge management

Social learning

State (computer science)

Pathology

Chaos Solitons & Fractals

According to the standard imitation protocol, a less successful player adopts the strategy of the more successful one faithfully for future success. This is the cornerstone of evolutionary game theory that explores the vitality of competing strategies in different social dilemma situations. In our present work we explore the possible consequences of two slightly modified imitation protocols that are exaggerated and gradual learning rules. In the former case a learner does not only adopt, but also enlarges the strategy change for the hope of a higher income. Similarly, in the latter case a cautious learner does not adopt the alternative behavior precisely, but takes only a smaller step towards the other's strategy during the updating process. Evidently, both scenarios assume that the players' propensity to cooperate may vary gradually between zero (always defect) and one (always cooperate) where these extreme states represent the traditional two-strategy social dilemma. We have observed that while the usage of exaggerated learning has no particular consequence on the final state, but gradual learning can support cooperation significantly. The latter protocol mitigates the invasion speeds of both main strategies, but the decline of successful defector invasion is more significant, hence the biased impact of the modified microscopic rule on invasion processes explains our observations.

Gradual learning supports cooperation in spatial prisoner’s dilemma game