Fig 1.
Payoff matrix of the “donation game”.
The entries in the matrix refer to the payoffs of player A. The benefit of cooperation (b), the cost of cooperation (c), and b − c are greater than 0.
Table 1.
Ten strategies tested in the model.
Fig 2.
The number of dominant results for nine strategies tested in pairwise contests.
AC stands for always-cooperate. AD stands for always-defect. AT stands for always-trembling. TFT stands for tit-for-tat. GTFT stands for generous tit-for-tat. TWTH stands for TFT-with-trembling-hand. SDH stands for shame-driven-hiding. SDD stands for shame-driven-denying. GDA stands for guilt-driven-amending. P stands for Pavlov. (A) When b = 1 and c = 0.75, the ranking of nine strategies. (B) When b = 1 and c = 0.5, the ranking of the strategies. (C) When b = 1 and c = 0.25, the ranking of nine strategies.
Table 2.
The average fitness payoff for ten strategies competing in a group under the conditions that group size is 50 (n = 50), benefit equals 1 and cost equals 0.25 (b = 1 and c = 0.25).
Fig 3.
The average fitness payoff for five homogeneous groups which adopt the error-prone strategies at four different error rates.
TWTH stands for TFT-with-trembling-hand. SDH stands for shame-driven-hiding. SDD stands for shame-driven-denying. GDA stands for guilt-driven-amending. P stands for Pavlov. (A) When b = 1, c = 0.25 and n = 10. (B) When b = 1, c = 0.25 and n = 20. (C) When b = 1, c = 0.25 and n = 50. (D) When b = 1, c = 0.25 and n = 100.