Lessons in a Foraged Past?

I tend to bring up my dad a lot on this blog - on the surface we don't often agree on politics and his sometimes negative reactions to my ideas on environmental issues allow me to confront my assumptions. During one particularly heated exchange a few months ago, he accused me of wanting to send modern human civilization back to living in huts, back to collecting "nuts and berries" as the Talking Heads lyric goes. Setting aside the possibility that our current consumptive lifestyle may be sending us in that direction anyway, is his charge correct? And if so, should I deny or embrace it? 

Like many people, my dad would characterize the hunter-gatherer condition as Thomas Hobbes did: "nasty, brutish, and short", full of conflict and poverty. A counterpoint to this argument is contained, interestingly, in a book about the evolutionary psychology of sex that came out in 2010: Cacilda Jethå and Christopher Ryan's Sex at Dawn. I haven't yet read the book but I've gotten the gist of it from a recent interview and some of Ryan's articles. While the book primarily examines how modern notions of monogamy and "proper" sexual behavior didn't exist in pre-agriculture societies, their research also draws broader conclusions about the central importance of cooperation and sharing in these societies - sharing sexual partners, yes, but also everything else:
What if—thanks to the combined effects of very low population density, a highly omnivorous digestive system, our uniquely elevated social intelligence, institutionalized sharing of food, casually promiscuous sexuality leading to generalized child care, and group defense—human prehistory was in fact a time of relative peace and prosperity? If not a “Golden Age,” then at least a “Silver Age” (“Bronze Age” being taken)? Without falling into dreamy visions of paradise, can we—dare we—consider the possibility that our ancestors lived in a world where for most people, on most days, there was enough for everyone? By now, everyone knows “there’s no free lunch.” But what would it mean if our species evolved in a world where every lunch was free? How would our appreciation of prehistory (and consequently, of ourselves) change if we saw that our journey began in leisure and plenty, only veering into misery, scarcity, and ruthless competition a hundred centuries ago?
My tweep GLEthnohistory (Great Lakes Ethnohistorian Megan McCullen who blogs here) tipped me to a more nuanced view of pre-ag societies in the book The Foraging Spectrum: Diversity in Hunter-Gatherer Lifeways. Here's an excerpt from a review of the book, which warns about the dangers of simplifying the past for good or ill:
Hunter-gatherers are not the alter ego of Western civilization; they are not simplistic societies; they are not humanity in a virginal state of nature; they are not Pleistocene relics; they do not preserve ancient ways of life; and we cannot reconstruct ancient human society by extrapolating backward from living hunter-gatherers (p. xiii). Throughout the text Kelly achieves his objectives by elucidating the variability which has been observed in the foraging lifestyle and by giving account of the factors which have led to variability; these include differences in subsistence activities, mobility, trade, sharing, territoriality, demography, and socio-political organization.
Aware of this diversity, anthropologist Greg Downey hesitates to endorse Sex at DawnAs appealing as Jethå and Ryan's findings are (our ancestors cooperated better, had a broader conception of the family than we do today), it may not be entirely accurate:
Although many of their innovative ideas are well worth considering, if for no other reasons to cleverly counter-balance other pervasive accounts of human sexuality in evolution, the book does run the danger of a competing partiality, however important the corrective may be.
I'm constantly looking for models of the future. If our present world isn't working for us, is the past a better model? If anthropologists reject a monolithic "past", or an overarching "human nature", how will we know what works, what kind of future we should be building together?