Social sciences tend to reflect the prejudices of their time. Knossos was famously "reconstructed" in art deco style, and there are countless examples of the present influencing the way we regard the past. So it's very unwise to assume that any study, or even related groups of studies can be relied on - especially in anthropology with its long history of wish-projection. The question of whether or not hunter-gatherer societies tend to allocate roles based on gender is highly contentious and today it is Politically Correct to want to assume they were far more egalitarian than contemporary evidence would support. Perhaps they were, perhaps they were not - especially given the biological fact than in general men are larger and stronger than women which has clear implications for hunting. The real fact, however, is that the modern world we've constructed with our amazing technologies is so unlike hunter-gatherer societies that the issue is totally irrelevant. Even if hunter-gatherer societies based roles entirely on gender, it is of no importance whatsoever to us living today. Our task is to ensure equality of opportunity and reward right here and right now, not to fight pointless ideological battles over scraps of evidence that can be interpreted more or less in any fashion one chooses.