Unconditional cooperators must be modeled separately from image-scoring discriminators.

Evidence

Indirect reciprocity only works when donors discriminate between individuals that have or have not helped others in the past. To understand the role of indiscriminate altruists, we add to the population of defectors and discriminators a fraction z of cooperators, who always give help irrespective of the their co-player’s score. — Nowak, M. A., & Sigmund, K, Evolution of Indirect Reciprocity by…, 114

Categorization

• XREF: connects to: A two-level analytical image-scoring model can be solved rather than simulated — Nowak, M. A., & Sigmund, K, Evolution of Indirect Reciprocity by…, 74

Related

• A two-level analytical image-scoring model can be solved rather than simulated (similarity 0.89)
• An image score updates only when one acts as donor, not as recipient. (similarity 0.82)
• Cooperation in image-scoring populations requires only about two interactions per player per lifetime. (similarity 0.82)
• Discriminator strategies base aid on recipients’ most recent recorded move. (similarity 0.81)
• Donor-specific image scoring sustains cooperation while self-only strategies fail (similarity 0.79)

Broader Connections

• A two-level analytical image-scoring model can be solved rather than simulated #expands (0.80) — Nowak, M. A., & Sigmund, K, Evolution of Indirect Reciprocity by…, 74