It would be best to have no memory,!® to forget that past defections may be repeated in subsequent moves. But in the case of individuals who do have some (finite) amount of memory, this is to prescribe as rational the avoidance of unconditional distrust even after the evidence would suggest it to be advisable. One inflicted 'wound', in this argument, should not be considered a sufficient reason for prolonged retaliation once the other side has been tamed by the first retaliatory response. Some degree of revealed preference for defection, in short, does not mean the absence of an interest in cooperation.

Diego Gambetta, Trust - Making and Breaking…, loc. 2812