Female plasticity tends to reduce sexual conflict.

Sexual conflict is the divergence of evolutionary interests between the sexes. A neglected aspect of sexual conflict theory is that the conflict often occurs within the female's body, which can lead to a power asymmetry between the sexes. In particular, the female may often be able to respond flexibly to the actions of the male, and so exhibits plasticity. Here, we consider the implications of female plasticity, and find that it tends to result in lower levels of sexual conflict. We then relate our results to a comparison of pre- versus post-copulatory sexual conflict, and we also show that this asymmetry between males and females reduces the likelihood of runaway selection, preventing co-evolutionary arms races. Finally, we discuss our results in the context of the evolution of adaptive harm and sexual conflict when there are direct benefits.