Nonstrong reciprocal thirdparty punishment is a necessary means to maintain the order of group cooperation. However, the means has some knotty dilemma of its own, which can be softened only by strong reciprocal punishment as an important measure. Therefore, strong reciprocal punishment can be embedded in group social capital if the groups are qualified for strong reciprocal punishment. But nonstrong reciprocal thirdparty punishment is to be introduced if the groups are not qualified enough for strong reciprocal punishment conditions. A proper combination of the two punishments can help effectively soften the dilemma of punishment and exercise the function of punishment to the greatest degree. Thus to harmoniously maintain the order of group cooperation, the function of strong reciprocal punishment should be fully promoted by developing group social capital under the support of nonstrong reciprocal thirdparty punishment.

punishment dilemma; social capital; thirdparty punishment; group cooperation; strong reciprocity