Fig. 6.

Complementarities (here shown as the sum of the male–female complementarity $\kappa$ and the male–male complementarity $\mu$) and differential production of dads versus cads ($Y_D-Y_C$) determine the game class and thus the asymptotically stable states and evolutionary outcomes. When $Y_D<Y_C$ at intermediate levels of complementarity, the game class is [cads and dads], meaning that dads and cads coexist in a polymorphic stable state. When $Y_D\ge Y_C$, any stable state is monomorphic. $\varphi =1/2$; $Y_D=2.5$; $A=20$; $x=5$.