I have a hunch we have no clear, coherent idea what "culture" means. I suspect it may be this simple: it's what enabled us to function in groups larger than ten or fifteen people when we began to make the transition from hunting and foraging to planting and tending and harvesting. I suspect the "natural" human group is a family or somewhat extended family or band. As those small groups grow larger, they become more stressful, so we developed culture as a means of channeling and redirecting and alleviating stress. How well does that work when groups exceed dozens or hundreds and evolve into thousands or tens of thousands?
How genetic is culture? How does it evolve? How much of it is language-based? How can we measure and compare any of this stuff? Are we even sure hunters and foragers led more precarious, more poorly nourished lives than agriculturists?
When I was a kid, I assumed I'd have answers when I grew up. Now I've embarked upon my second childhood—a vast improvement upon the first, by the way—I can truthfully tell you questions reproduce far more rapidly than I could ever have imagined, and answers seem an endangered species.
We know the opposite is actually true. When comparing hunter/gatherer skeletons with the earliest farmers, agriculture was not an advance in health. Farmers died younger, and were shorter and less healthy. The big mystery is why, and why we kept doing it if it was not an improvement.