Monkeys show sense of justice

Monkeys have a sense of justice. They will protest if they see another monkey get paid more for the same task… Scientists say this work suggests that human's sense of justice is inherited and not a social construct.
Oh, Lordy, here we go again: creating false genetic/environmental dichotomies. Given that monkeys live in societies, in what way does this experiment suggest that a sense of justice is genetically-based and not a social construct? And why can't it be an inextricable combination of both (which is where my money lies)?