Beyond tit-for-tat
Once TFT evolves, can other strategies invade?
Subsequent work indicates that other trajectories may occur, e.g. TFT-> Generous TFT-> Pavlov-> cooperation (Nowak & Sigmund)
- If mistakes are made, Generous-tit-for-tat does better than TFT (GTFT cooperates after opponent cooperates but also after opponent defects with some probability)
- Pavlov - win-stay, lose-shift does better than TFT because it corrects occasional mistakes and exploits unconditional cooperators.