I find conversations about comparative primatology fascinating, both as a topic of interest in and of itself, and as a cultural artifact reflecting the assumptions of the day. Public voices like to use speculative work like this to justify any number of sociopolitical ends, a process which as a cultural anthropologist I find interesting. In many respects, plunging an entity like "biology" or "physics" for social models to use is a more creative and flexible act than people realize, or that many would care to admit; the simple fact is that a significantly complex system can be used to justify any number of social positions, owing to the complexity and variability within that system. DNA may not be a literal book, but that doesn't necessarily stop the bioanthropologist from "poaching in the stacks" of genetic potentialities in much the same way that Michel de Certeau meant when he coined that phrase. We are always moving through the library of human knowledge with certain goals and purposes in mind.
This is getting long-winded, but I felt it should be pointed out. Every time someone tells you a narrative about "how things used to be", they are also telling you a narrative about "how things should be", whether they are making an essentialist argument of returning to base or a revolutionary argument about what we must overcome. Either way, I think it is important to remember that you are being told a story; one that though likely true and justifiable in some respects, chose its data points selectively and for subjective reasons. The human biological pedigree is vast and complex, let alone our cultural history, and any number of social models could be found in or justified by the situation various points along the way. Between ourselves and the chimpanzees, our genetic closest cousins, there sit nearly 4 million years of history at the inside, and maybe as many as 11 million years of genetic diversion and cultural invention. Don't let that number just drift past you. "History", to you, is comprised of possibly 1/2200th of the time depth since that divergence. And between have been many variations. Strict herbivores, omnivores, and mostly-carnivorous variants. Savannah dwellers, forest dwellers, tundra dwellers. Everything from troupes to tribelets to communist states. Gender-dyadic societies and gender-spectrum societies. Patriarchies and matriarchies both.
And let us not forget the physical differences; an adult human is so physically different from an ape that neotony has been suggested to explain our seeming lack of a meaningful final adult growth spurt. We don't have an estrus cycle, alone among the primates. We usually have the largest male sex organs as well as the largest mammary glands in the entire order. We otherwise also present the least overall sexual dimorphism, to the point that forensic anthropologists frequently mis-type sex, at a rate that would be inconceivable within a gorilla assemblage. So not only does biology allow for critique of cross-species analogies, sex and gender are areas in which biology should be warning us to be especially cautious; sex differences are one of the things that make us the most anatomically distinct from our cousins, not similar. And the other major difference, our brains - a chimpanzee peaks with mental equivalency to a human toddler - means that our extra-cranial anatomy may have much less influence on an individual's life than it would for any other primate. Chimpanzees, too, in turn changed greatly over time and no longer resemble our presumed common ancestor in closely analogous fashion; as we became dissimilar to them, they were also becoming dissimilar from us, in different directions for different reasons. Nowhere is this clearer than in studies of chimp-human cohabitation cases and experiments; our social instincts diverge from chimps qualitatively, not just in degree.
I am not saying that one shouldn't make observations or suggestions based on comparative primatology. We can, and do, and especially when we find that the entirety of the primate order holds something in common, the cultural anthropologist gets very interested indeed. We are apes ourselves, and despite our distinctive qualities as a species, our heritage shows its face somehow or other in nearly everything we do (and not just the primate portions of it, read "Your Inner Fish" sometime if you want your paradigm shook up a bit). But the natural limitations of such analogies should also be considered, and we are justified in always asking about the motivations of a given theorist when they highlight this fact from this cousin at this time rather than another.
