Likely advancement of quality-absorbing sapient

Question

Many anthropologists believe that equatorial Africa became super culturally-advanced and technologically stunted compared to the rest of the Old World in large part because of 1. Lack of trade routes, and 2. An environment that was naturally suited to human occupation without need of many tools.

My story takes place in an area of Earth-like savanna, mixed forest, and seasonal tropical forest, very similar to coastal West Africa. Much of the rest of the world is just emerging out of the middle ages. However, this species has the ability to have parts of their body temporarily take on a single physical quality of something they touch and temporarily removing that quality from the object. Need to crack open a nut? Make a fist, touch a dense rock, and lo! you have a nutcracking hammer for the next few minutes. Absorb the stiffness out of a log and someone else can bend the log into a pretzel before it re-hardens.

So basically, the environment is very accommodating to life and any need for tools can be mitigated by interaction with their immediate environment. There is really no 'need' to advance beyond stone-age technology. I frankly can't think of any cultures we know about that advanced into the bronze age for any other reason than 1. The environment or neighbors changed faster than they could adapt or 2. First contact with an exploratory/conquering culture.

So! Question. Aside from outside influence/trade (and thereafter likely 'collecting' trade goods with qualities they want to emulate like steel or a sponge), are there any historical reasons a human-like culture such as this would ever want/need to leave the stone age?

Answer 1

In reality, examples for the behaviour you describe exist. Yet, your question asks for possible motivations to start such a cultural evolution. I want to present two possible ones:

First, by considering only external motivations/pressure in your question you seem to forget about one of the most imporant internal motivations and driving forces for human advancement: curiosity. Do you need external pressure to advance in order for the most curious to start wandering further from their homelands looking for new materials with new qualities, maybe to use, maybe to sate their own curiosity or even to impress others with the rare and wondersome?

Second, a part of the gathering/'collecting' nature of humans is the appreciation of the wonderous and beautiful - coloured jugs with basic motifs, woven cloth dyed in different ways or jewelry made of bone, stone, wood is found in stone age cultures already up until highly advanced ones The appreciation of arts in all its forms is part of our nature. Also, no external power enforces the creation of instruments, yet you find instruments or the most basic of instruments - the human voice - in any culture around the world.

Answer 2

Pain, Suffering, and Medicine

People get desperate when they suffer. Diseases are everywhere. You can't develop modern medicine without modern technology. A parent watching their child suffer and die painfully is (thankfully) considered a rare occurrence in our modern world. In fact, I'd encourage you to look more into child mortality rates - the number of children who die before five years of age was around 30% in much of the world, and as high as 50% in many places until the late 1800s - and that's crazy!

Pain and suffering are motivators - such a civilization (especially one with more ability to absorb / experiment) - might be willing to travel farther and explore further into unknown regions, or to invest more time into thinking beyond stone-age technology out of the desire for alleviate the suffering of loved ones - especially children.

From limited resources, to simple things like plumbing (the toilet has saved many lives), to medicine, to even ultrasounds and c-sections, there would be great emotional desire to reduce suffering.

Greater Comforts

@Alex2006 gives great points here so I won't duplicate him: curiosity, appreciation, arts.

But even ideas around controlling temperature (A/C units), making certain specialties easier (the printing press), or automation (computers) would increase comforts.

Population Density

What could occur on it's own, but almost certainly would occur as an extension of the above points (lower child deaths, less suffering, better comforts), would inevitably lead to a denser population.

As populations get closer together, the opportunity for specialties rises. As well as the needs of the population. Traditional farming only grows so much - the first industrial revolution changed that, and then again the second! The need to optimize farming for more people in a smaller area requires people to think more about issues not previously thought about - can we make food grow faster/bigger? Can we grow food inside a building? Can we make buildings more than two stories high (that will require more than simple mud-and-straw bricks).

Structural issues, transportation, food, policing tactics, cultural reforms, etc, are all issues that can arise from denser populations, and would encourage the society to advance technologically.

Threat From (Future) Advanced Civilizations

Much to your own point of outside threats, no matter how sustainable a civilization is, there will always be the possibility of a greater civilization. Even if your society is not currently being addressed by an outside threat, there can / will be an outside threat at some point. If your society is aware enough that there might maybe someday be an outside threat, you don't want to wait to meet them to begin developing technology. This is like meeting tanks with arrows, or atomic bombs with tanks, or UFOs with missiles. The possibility of an enemy is a great motivator.

We see this even in the past hundred years with the advent of atomic weaponry - once we understood that greater weapons were theoretically possible, we began building technology not around what our enemies have today, but what we think they might possibly have tomorrow - that's a far scarier (and greater challenge for progress) than ever before. Even if a society is "stable" economically, socially, religiously, etc, an enemy with an atomic weapon could wipe you out instantly. Simply put, the only limit to a theoretical future threat is your imagination - not the (disease/weapons/technology/people/creatures) which exist now. No matter how advanced you get evolution-wise, the technological capacity of humankind significantly out-grows the capacity of humankind on individual biological basis.

Although your society might be able to "absorb" a metal, rock, log, etc - this necessitates that the thing they acquire already exists. This is problematic. The creation of atomic weaponry (to stick to the example), necessitated the technological combining of many different rare elements (like plutonium and uranium) - and acquiring these resources means traveling great distances and transporting sensitive material great distances. Then, of course, comes the issue that radiation is dangerous to most forms of life, and is obviously something your creatures would not want to absorb without very costly consequences.

So the idea of a potential future threat would drive technological progress.

Answer 3

First, I would say that the terms like 'stone age', 'bronze age' and 'iron age' are pretty vague. It's not the only natural progression of events, but rather the accident of the history of the whole region of Eurasia and Northern Africa, that was interconnected pretty early. Even if we take a look at the Mesoamerican civilisations, the division is much more hazy there. That on itself is a good example that your can have complicated architecture, capital cities, division of labor and hierarchies even with stone tools.

From what I know if anthropology, the complexity of social structure depends on population pressure and difficulty of feeding the given population with available tools. Obviously, there are other important factors like the level of healthcare and so on.

So this is for you to decide, how densely does this species populate their territory, how hard is it to feed them all and how specialised do the food producers need to be - their social structures would rather depend on the patterns of food production then on the material of their tools. And I wouldn't call their tool use 'stone-age' either. They, obviously, use tools, but not directly to perform a task. Most likely, they would carry the examples of different materials and use them to 'borrow' their qualities.

Answer 4

War

Even in "not so competitive" environment, humans have been known to enter into tribe fights and the like. so yeah, At one time or the other, your humans will fight. From here on, absorbing harder rocks than your opponent is a decisive advantage. So you will refine "better rocks" eventually leading to metal, eventually leading to weapons, and now your absorbing capacity is fine for cooking without burning yourself, but won't compare to throwing pointy/flaming/exploding sticks on people. Even if it does, you will need to defend homes and goods (food, at first), so you will have walls, then houses, then forts..

In our current society, technology improvements are pushed by the military for attack or defense. It goes from pointy rocks to the internet, but also horse riding and creating new drugs. If there is one thing where humans have been proven creatives, it's getting new ways of killing people.

In your preset universe, you need only 3/4/5 tribes to hate each others for whatever reason (some unoriginal greek mythology stuff works fine, forbidden love, stealing food or goods, even some random accident, then some vengeance, then some more, and boom, perpetual war), evolving to fight one other one, to try and get the leading edge.

But as soon as one got an advantage, the others will fear annihilation and group up, one will go with another tech, maybe even share it, and you can keep status quo going for ever and ever, like European kings with their alliances did for hundreds of years.

If you play any 4X game with some decent AI, or good players, you will see that diplomacy has a tendency to keep things going for pretty long if everybody wants to stay alive and compete. Europa Universalis is a good example at bringing coalitions as soon as some power gather too much under one authority.

So yes, just fighting each other will make tribes evolve, and one won't be able to annihilate the others once one step is reached.