conformists dramatically increases the group size for which cooperation can be sustained. The results of our model are robust …

Gratuitous cooperation (in favour of non-relatives and without repeated interaction) eludes traditional evolutionary …, conformism and gratuitous cooperation co-evolve, and group selection is a necessary ingredient for the co-evolution to take place …-mutations (e.g., the rare emergence of a charismatic leader that brings order to the group) are necessary to sustain cooperation in …