Occasionally, the studies purporting to show cross-cultural sex differences actually show that the differences are smaller in the more egalitarian countries.

On some measures they show the opposite - differences being smaller in less egalitarian cultures - although the relevant point there is that they have both sexes trending in the same direction (typically the traditionally "male" one.) The two most obvious explanations I can think of for this are that the relative distance is an artifact of survey estimates (we can say for some constructed variable w1 < m1 < w2 < m2, but to map those onto an absolute scale is a further act of interpretation - I'm not familiar enough with the methodology of individual surveys to say whether this is the case) or that cultural liberalization and individualism has benefited (or, if your values swing that way harmed) everyone, but moreso men. (In a traditional society, men have their roles and women have theirs, but everyone is expected to obey their natural superiors, and the model of the rugged individual is peripheral. In modern societies the rugged individual is a prominent male archetype.)