I realize people from Arguedas and Valtierra have a reputation of not being particularly Sapiens, specially among their neighbors, but they were still living in caves in the last century. In fact, many of the people who have caves still use them in summer, as they’re naturally cool: moving to the cave is cheaper than setting up A/C in your house.
They’re not the only ones, just the ones closest to my home town.
These people have gone fancy and turned several of the caves into a hotel. It’s not just something they came up with: those caves were people’s permanent homes until the 1960s and 1970s. The Spanish government had serious troubles convincing people to move from their ancestral homes to the government-built houses.
Numerous Mesolithic cave dwelling sites are known from Southern France, Germany, the Czech republic, Slovakia etc., according to Mesolithic in Europe (2008). Since the level of preservation and the degree of stratification is usually much better in caves than on open-air sites, much of what is known about the early Postglacial Homo sapiens in these regions is derived from caves with hearths, butchered animal bones, tool remains, the works.
It is true that cave art caves were not used as dwelling sites, though.
Limestone and karstic caves seem to have been preferred for cave living in Europe. I don’t know if these are appreciably different from Blake’s bleak description of the cave environment; at least soft limestone can be leveled for a floor if need be. At any rate, making a waterproof lean-to with Stone Age tools isn’t all that straight-forward or energy-efficient in many environments, having been there and done that.
As per the OP, due to accident of preservation, it is impossible to estimate what percentage of the population lived in caves in the aforementioned regions. Many people did, in any case.
That’s been my (admittedly limited) experience. The limestone caves I’ve visited around here (in the Swabian Alb) are all rather comfortable in terms of humidity, temperature, and flooring, and indeed were historically inhabited by humans and other large animals. Water is plentiful both inside and outside, though I can’t speak to its potability. There is ample and unambiguous evidence that humans slept there as long ago as 20,000 BCE and as recently as the 16th century CE. Sure, there are plenty of rough patches where you wouldn’t want to bed down, but there are also lots of areas where the ground is fairly level and away from the damp.
As to whether the caves were inhabited by “our ancestors”, absolutely—the descendants of the last known inhabitant of one of the caves are still around today.
Even the Wiki article on cave dwellers says at the end that millions of Chinese people still live in caves. Another blog I noticed said 40 million, but that was unverified…
As I understand it from general reading over the years, most of them don’t live in ‘proper’ rock caves but caves dug out of softer material in river banks, cliffs, etc.
Yeah, I was going to mention the 1556 Shaanxi earthquake which killed approximately 830,000 people. Most of the population in the area at the time lived in yaodongs, artificial caves in loess cliffs, many of which collapsed during the catastrophe with great loss of life.
Think about this a moment. If you’re crawling in the pitch darkness, you’re already in the cave. Anywhere that’s big enough to crawl through is big enough to sleep in, as long as you don’t get into the habit of sitting up as soon as you awaken.
What Blake is saying is that there is often a narrow tunnel leading to the larger cave. You might have crawl or wriggle for hundreds of yards before getting to the cave proper. One person might sleep in a tunnel, but a band of hunter gatherers is not going to live in the tunnel leading to the cave.
To address the question - from what I’ve read, prehistoric homo sapiens did indeed live in caves on occasion (as we still do), but the actual percentage of occupation can never be determined (although it was probably quite small).
As others have noted, the “cave man” image is purely a matter of the accidents of preservation. Stuff left in caves has a much, much greater chance of being preseved for thousands of years than stuff left in the open on riverbanks and lakeshores, where no doubt most homo sapiens lived throughout history in warm weather - easy access to water, fishing and game; plus, as anyone who has ever camped could tell you, having a nice breeze over water in summer keeps the bugs down!
Modern work on reconstructing post-holes and the like is starting to change the “cave man” image, but post-holes and middens are simply not as spectacularly memorable as the fantastic cro-magnon cave art (much of which appears not to have been made in caves people lived in - painting that stuff seems to have been more of a ‘dangerous ritual in the dark’ thing, possibly connected with shamanistic magic of some sort, than wall-decorations for the home).
I’m imagining it did not take a great deal of brainpower to go from "shelter under this bush or low tree " to “build up the protection by piling on dead branches and leaves to enhance the roof and walls” to “I can build an entire shelter without needing a live tree in the middle”. Once the concept is out there - well, there are an incredible variety of different shelters made from local material by assorted hunter-gatherer and nomadic societies. Speed of assembly and available local material would be the key criteria.
I’m sure where caves were convenient they were recognized as useful shelter. Fixed permanent shelter of course required a permanent base and a steady food source. Were many non-agricultural nomads able to live out of a fixed location? Hunting would have to be pretty good! That would be the big problem with cave dwelling - the game mght get sparse, so you would probably only occupy these sites on a seasonal or irregular basis.