Before revision:  In general, our evolutionary model provides stronger evidence than Mark's original model with respect to how status behavior can facilitate the emergence of social cooperation .
After revision:  In general, our evolutionary model provides stronger evidence than Mark's general prediction. For theory, our work further reveals two novel phenomena of group cooperation: Both the relative number of cooperators to defectors in groups and the assortativity among these different roles can backfire; they are not always the higher, the better for cooperation to thrive. For methodology, the hierarchy measure developed and our model using the measure may also be applied in future research on a wide range of related topics .