De Dreu and Gross's description of the proximate mechanisms conditioning success in intergroup conflict omits humans' deontological morality. Drawing on research on sacralization and moral objectivism, I show how “moral rigidity” may have evolved through partner selection mechanisms to foster coalitions’ cohesion and combativeness in intergroup conflict.

Baumard suggests that the advent, through phenotypic plasticity mechanisms, of future-oriented preferences and creative mindsets in eighteenth-century Great Britain explains the wave of innovations that drove the British Industrial Revolution. We argue that, although this approach is promising, Baumard's model would benefit from being supplemented by demographic, economic, and sociological explanations independent of Life History Theory.