“When you think about it, because of the way evolution works, humans are probably hovering right around the bare-minimal level of rationality and intelligence needed to build and sustain civilization. Otherwise, civilization would have happened earlier,”
I actually profoundly disagree with this both empirically and theoretically.
Civilizations are not some kind of natural inevitable ‘next step’ that must happen when you have a smart animal. They are a thing that CAN happen in the context of a smart animal that is capable of inventing agriculture. But there are other prerequisites.
I find the argument that complex culture is a thing that can happen in dense enough human populations, running away as it further densifies the population, persuasive. The idea is that in a low density human population ideas sometimes fail to percolate down the generations, while in a dense enough social network innovations stick down the generations more frequently because losses are less likely. It is possible that you can reach a ‘tipping point’ in a dense enough population at which point the ability to pass on new innovations allows a denser population still and further accumulation of complex culture.
There is a bit of a case study in Tasmania. The native Tasmanian population had continuity with the aboriginal Australian population before the end of the ice age, when the two landmasses were united. Ten thousand years later, upon European contact, the Aboriginal Australians maintained oral culture of events and places tens of thousands of years back, and had kept and expanded upon the toolset that existed in the united landmass… while the Tasmanians, with a smaller social network and a less dense population on that land, had lost large numbers of tools and skills including the ability to produce fire de novo (while still being able to propagate it).
I think Neanderthals are also likely evidence pointing in this direction. Their brains were more or less the same size as ours, and they had a common ancestor a full 500,000 years ago with us. But they lived in the frozen wastes of ice age Europe, in small isolated subpopulations if the homozygosity of the neanderthal paleogenomes is to be believed, with LOTS of small subpopulation bottlenecks. That’s a perfect recipe for repeatedly losing your complex material culture down the generations.
Empirically, human brain size has also been on a downtrend for the past fifteen thousand years as agriculture and civilization has spread. It is a simpler environment with fewer complex things you need to interact with on their own terms and significantly worse nutrition, so we give up some small fraction of our highly expensive intelligence over long periods of time.
Good points. I think I agree with everything you said, so I’m confused as to why we disagree. I guess your model is that we got intelligence + rationality first, and then civilization came later when we had population density, and therefore we might have more intelligence + rationality than we need to sustain civilization. The fact that brain size has been shrinking supports this; maybe we were more rational 15,000 years ago, or at least more intelligent.
I think my claim is still true though—it does seem like civilization would collapse if we got significantly dumber or less rational. I guess I had been meaning “hovering around bare minimum level” more loosely than you.
I think I concede that my argument was shaky and that we probably aren’t at the bare minimum level for reasons you mention. But I still think we are close, for a loose definition of close.
“When you think about it, because of the way evolution works, humans are probably hovering right around the bare-minimal level of rationality and intelligence needed to build and sustain civilization. Otherwise, civilization would have happened earlier,”
I actually profoundly disagree with this both empirically and theoretically.
Civilizations are not some kind of natural inevitable ‘next step’ that must happen when you have a smart animal. They are a thing that CAN happen in the context of a smart animal that is capable of inventing agriculture. But there are other prerequisites.
I find the argument that complex culture is a thing that can happen in dense enough human populations, running away as it further densifies the population, persuasive. The idea is that in a low density human population ideas sometimes fail to percolate down the generations, while in a dense enough social network innovations stick down the generations more frequently because losses are less likely. It is possible that you can reach a ‘tipping point’ in a dense enough population at which point the ability to pass on new innovations allows a denser population still and further accumulation of complex culture.
There is a bit of a case study in Tasmania. The native Tasmanian population had continuity with the aboriginal Australian population before the end of the ice age, when the two landmasses were united. Ten thousand years later, upon European contact, the Aboriginal Australians maintained oral culture of events and places tens of thousands of years back, and had kept and expanded upon the toolset that existed in the united landmass… while the Tasmanians, with a smaller social network and a less dense population on that land, had lost large numbers of tools and skills including the ability to produce fire de novo (while still being able to propagate it).
I think Neanderthals are also likely evidence pointing in this direction. Their brains were more or less the same size as ours, and they had a common ancestor a full 500,000 years ago with us. But they lived in the frozen wastes of ice age Europe, in small isolated subpopulations if the homozygosity of the neanderthal paleogenomes is to be believed, with LOTS of small subpopulation bottlenecks. That’s a perfect recipe for repeatedly losing your complex material culture down the generations.
Empirically, human brain size has also been on a downtrend for the past fifteen thousand years as agriculture and civilization has spread. It is a simpler environment with fewer complex things you need to interact with on their own terms and significantly worse nutrition, so we give up some small fraction of our highly expensive intelligence over long periods of time.
Good points. I think I agree with everything you said, so I’m confused as to why we disagree. I guess your model is that we got intelligence + rationality first, and then civilization came later when we had population density, and therefore we might have more intelligence + rationality than we need to sustain civilization. The fact that brain size has been shrinking supports this; maybe we were more rational 15,000 years ago, or at least more intelligent.
I think my claim is still true though—it does seem like civilization would collapse if we got significantly dumber or less rational. I guess I had been meaning “hovering around bare minimum level” more loosely than you.
I think I concede that my argument was shaky and that we probably aren’t at the bare minimum level for reasons you mention. But I still think we are close, for a loose definition of close.