er strategy: loners do not play the game; hence, they pay no cost and receive no benefit. Let us first analyze these strategies using the result of Antal et al 2009c. Then the conditions for C, D and L respectively to be selected for are Lc = (13 — 3c) > 0 (6.30) LD = g > 0 (6.31) LL = 3(—b+c)> 0 (6.32) C