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Evolution of mind

  1. May 12, 2015 #1
    I got to wondering about the development of the human brain, and the consequent development of human intelligence (and to an extent the mind). I googled the question and after reading several articles, was left not much the wiser in regard to the development of 'intelligence'. Part of my problem is not knowing what 'intelligence' is.

    However, I think what I mean is that today's body of human knowledge is quite extensive. A smart well educated man today can know a lot of facts and can entertain rather sophisticated ideas about the nature of the external and internal environments. A scientist can know quantum theory, advanced cosmological concepts, deep knowledge about biology and microbiology, ever increasing understanding of the functions of the brain and mind itself.

    This knowledge, this mode of thinking, is far in advance of the mind of a man of say 10,000 years ago. Yet how has the brain changed in that time to facilitate this?

    My reading tells me that the size of the human brain increased over the course of several millions of years until around 10,000 years ago when brain size began to decrease slightly. Today's brain appears to be about the same size, or slightly smaller than, the brain of 10,000 years ago. Yet I found little to describe how the internal structures of the brain might have changed in that time.

    Broadly speaking, I got the impression that the brain has not changed much other than size in the past 10,0000 years. The essential structures appear to have been well in place by that time.

    Presumably then, the potential of a human brain to know and understand the knowledge that we have today was present 10,000 years ago. That raises some intriguing questions about the mind. But I suppose first I need to know if that core fact is true.

    Has the human brain changed in the past 10-20,000 years? Or more exactly I guess, does science have a view on when the human brain developed its current form and function?
  2. jcsd
  3. May 12, 2015 #2


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    The human brain hasn't changed in any significant way in tens of thousands of years. The reason why people can know so much more today is thanks to:

    A) The accumulation of knowledge over thousands of years
    B) A socioeconomic setup that allows for, and even encourages, long periods of education.
  4. May 12, 2015 #3
    But this means that a modern human without the benefit of education or access to knowledge would be the same as a human of 10,000 years ago. It suggests that modern man's mind is essentially different due to the evolution of the mind itself. That is, accumulation of knowledge and long periods of education allow the human mind to form more complex associations and conceptual arrangements than it would otherwise be able to, regardless of the structure and function of the brain.

    The brain, or mind, of any human in the past 10,000 years has the potential to be as knowledgeable, as smart as a modern human. Yet it was not because the mind itself had not 'evolved'? What does this say then for people of today from impoverished backgrounds? Would say a human from a tribal culture without access to either knowledge or education have a less sophisticated mind, less ability to form deep abstractions about his environment, than say a university professor from New York?

    In effect, the accumulation of knowledge over time and the development of complex ideas and understandings can be informed to the modern brain by way of education and access (as you say), which further suggests that the mind of a person is more complex in earlier stages of life than in the past.
  5. May 12, 2015 #4


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    Correct, likewise if you were to take a baby from 10,000 years ago and raise it in a modern setting it would be the same as anyone here. It's worth noting however that humans of tens of thousands of years ago might have known less but were by no means less intelligent. They were still remarkably capable of thriving in their environment, planning how to survive and building tools to aid them.

    Education can (but doesn't necessarily) make one more intelligent, in the sense that you practice logical and critical thinking. That has nothing to do with evolution.

    No it's not because the brain has evolved significantly (I don't know what you mean by the mind evolving). People from impoverished backgrounds or primitive cultures are not necessarily less intelligent than a university professor. A professor has the benefit of education within their field and generally is quite intelligent but if you were to put them in the middle of a rainforest with no tools they would be in trouble. Conversely an individual raised in a tribe would be very knowledgeable on their environment but wouldn't know as much as the professor with regards to the professors field.

    I don't know why you think it automatically makes the mind more complex. Why would an intelligent person's mind be more complex than another? What do you mean by complexity here? I'd argue that the ability to form complex thoughts is superficial compared to the entirely of a person's psychology.
  6. May 12, 2015 #5


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    You might want to look into some anthropological studies of people who live in hunter gatherer tribes today (or at least in recent history). From what I've read there is no difference in intelligence between those and people who live in modern societies.

    In fact if I recall there is an argument that modern lifestyles may actually make us less intelligent. Figuring out which icon to tap on you iPhone is a lot less complicated than figuring out how to build shelter with only a set of sharp rocks.
  7. May 12, 2015 #6
    Yes I agree, I would need to read a lot more to gather a better understanding, but I think I can raise a few of my basic questions here and establish a starting point for understanding.

    What I've gathered so far is that the brain was largely in its modern form over 10,000 years ago. However, the accumulation of knowledge over that time, and the capacity to retain and share that knowledge has helped modern humans to have a deeper understanding of the universe.

    Apparently the capacity to learn and apply this greater knowledge existed in an individual from 10,000 years ago as much as in an individual today. The brain has not changed (evolved) in response to the more complex reasoning undertaken by individuals today.

    So the mental ability of a smart person today is not a result of a physical change in the brain, nor has this ability driven any physical changes in the brain.

    Now, the point that knowledge and capacity to apply knowledge is not intelligence escapes me a little here, but we can come back to that.

    The question of evolution of mind is what I want to consider. If all humans had never chosen to pursue knowledge and its application beyond basic survival, such as for example a primitive tribe in the Amazon, humans would not have relativity, theories of the origin of the universe based on scientific observation, quantum physics and so on.

    It seems to me that the way a mind works that permits these sorts of insights and mental frameworks requires an evolution of a sort. It requires the development of ideas over time, the retention of the learnings, and improved methods to apply these learnings. We codify this information into books and other records, but we still require that the mind be trained to be able to do so.

    We do that from birth. Our educational institutions and our workplaces place demands on our minds but equally train our minds to be able to do this. That is why a native from the Amazon, or a 40 yer old woman from 10,000 years ago, could not undertake a discussion with a modern quantum physicist.

    The modern physicist, or philosopher, or biologist, do far more intricate reasonings and maintain far more complex abstractions in their minds then did ancient man. Yet this is not due to a change in brain structure of function. And a pile of books of themselves do not confer that capability upon an ancient man. Or a modern Amazon indian. So 'something' has evolved over time. Is that simply knowledge? Or is it the mind (or more exactly, how a mind can be utilised)?
  8. May 12, 2015 #7


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    You are confusing the capabilities of the brain with information learned. Again, the brain has not "evolved/changed over the last ~10k years.

    If you take the child of a Nobel prize winner in physics and place them in a tribe in the jungle to be raised as one of them, when they grew up, they, as you put it, "could not undertake a discussion with a modern quantum physicist". I fail to see what your point is. It has nothing to do with the brain, but with information that is learned. To be clear, we are talking about equally healthy, normal brains.
  9. May 12, 2015 #8
    Yes I agree Evo. That is my whole point of interest. In thinking about how a human mind works, I began contemplating how it is that we think the things we do. It is clear that a man of 10,000 years ago simply could not have thought of a theory of relativity. So I wondered if the brain itself had changed over time to give rise to that capacity. Apparently it has not.

    now I know little of human anatomy or development or even the history of man beyond a basic awareness of the timeline. So I was working with an incomplete idea of how all of this works.

    So far, it is stated here that the brain has not changed. So the capacity to develop complex ideas and to form deep intellectual frameworks for inquiry evolved with no immediate application. It appears that somehow, the brain formed the ability to do this sort of thing without that sort of thing actually being done.

    I think it is not reasonable to claim that a man of 10,000 years ago was as 'intelligent' as a man of today. But as I said, I'm not sure what intelligence is. To know what spear point to use is trivial, as is to know what food to eat or how to bind a stone axe. these are simply matters of survival.

    The knowledge and application of knowledge today is far greater than the past. A smart man today is smarter, has more knoweledge, and can apply that better than a man of the past. our ideas in all things are far more developed - in science, in philosophy, in art, in music, policitcs, social and cultural frameworks, economics - you name it.

    So something has evolved. It's not the brain. it's not 'knowledge', for what is knowledge without a mind capable of understanding it and applying it?
  10. May 12, 2015 #9
    Society has evolved. Our ability to pass on knowledge to the following generations. As people have said before you vastly overestimate the importance of factual knowledge (semantic memory) to everyday functioning. There is more to our brain than that.

    Is it though? This reminds me of a quote about Paul Dirac (which I shamelessly copied from somewhere):
    Another time, Dirac was watching Anya Kapitza knitting while he was talking physics with Peter Kapitza. A couple of hours after he left, Dirac rushed back, very excited. "You know, Anya," he said, "watching the way you were making this sweater I got interested in the topological aspect of the problem. I found that there is another way of doing it and that there are only two possible ways. One is the one you were using; another is like that. . . . " And he demonstrated the other way, using his long fingers. His newly discovered "other way," Anya informed him, is well known to women and is none other than "purling."
  11. May 12, 2015 #10


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    Do you think that someone just woke up one day and knew quantum physics? I believe this is where your thinking has gone wrong. We know what we know today because we have been learning bits and pieces for thousands of years and building on those bits and pieces. It's not the brain that has changed, it's the fact that we gain knowledge, then add to that knowledge, the amount of knowledge is increasing, and our brains are capable of handling that new knowledge without having to physically change, please stop using the word "evolve".

    And if your ancestors hadn't learned to make that spear point or what food was safe to eat, you wouldn't be here right now, it was very important.

    As Ryan pointed out at the beginning of this thread, you could take a child from 10,000 years ago, and raise them as a modern human and they would have the same potential to learn everything that a modern human can. They would not be sitting around making spears.
    Last edited: May 12, 2015
  12. May 12, 2015 #11


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    If you think knowing how to make a spear tip is trivial of emplore you to go look up knapping and wood craft and try it yourself. Like many, many vocational skills it can take years to master.
  13. May 12, 2015 #12
    Perhaps another way to think about this is that we can use several modes of thinking. I would argue that scientific reasoning does not so much rely on developing an advanced intelligence, but rather has more to do with learning how to suppress otherwise useful modes of thinking in favour of slow, deliberate and highly accurate reasoning.

    Think about it like this: learning to speak is actually quite difficult when you think about it. Language is essentially a logical code, with many different rules and often allowing for ambiguous interpretation. Yet children are capable of learning it... simply by being exposed to speech. If you study language you realize the rules underlying it are actually not all that different from many other logical systems that we learn about in science. Speaking also requires advanced physical muscular coordination. It's just that because everybody does it that we don't perceive how amazing it is that every healthy human being can do it.
  14. May 12, 2015 #13


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    One might argue that most of the advances in human knowledge that you speak about came not from biological changes but from cultural and social changes. The transition from nomadic hunter-gatherer societies to sedentary, agrarian societies during the Neolithic Revolution is thought to have been key to the development of technology-based and knowledge-based societies. In societies with agriculture (domesticated plants and animals) could produce food much more efficiently allowing them to support larger populations with a smaller fraction of the population dedicated to food production. This allowed for the specialization of labor, in particular, the ability for societies to support a number of non-food producing individuals who specialized in the generation and propagation of knowledge and technology. For example, before the invention of the printing press, much knowledge was preserved by monks who would work tirelessly all day making copies of books by hand. It is hard to imagine hunter-gatherer societies being able to support such activities.

    Jared Diamond makes this point about the connection between agriculture and technological advancement in Guns, Germs and Steel when he points out that the most technologically advanced societies are those that arose in the geographic locations most amenable to the development of agriculture.
  15. May 12, 2015 #14
    Thank you for some valuable comments. I think some have misunderstood where I am coming from. Also Evo, I think 'evolve' is exactly the right word. I use the word evolve in a broader sense. The idea is not limited to the concept of physical evolution of organisms. In the context I am using it here in respect to the mind, or to knowledge, I simply mean that something has changed, has become more complex, or more complete, over time.

    Human knowledge is much richer, more complex and complete today than it was 10,000 years ago. I am not arguing that there is any intrinsic value to that, just observing the fact. Knowledge has 'evolved'. If you can think of a better word, I am happy to use it.

    I also still argue that making a spear point, or any other skill enjoyed by stone age man, is a relatively trivial task IF our brains at that time were the same as those of today. I would imagine that most members of any stone age tribe would have been able to do most of the normal day to day tasks to which they applied themselves. And pretty much any normally functioning stone age man should have been able to accumulate and assimilate every last bit of knowledge of his culture.

    Let me pose it another way. If a 40 year old man of today were transported to 10,000 years ago, could he have learned the various skills and knowledge of that culture? I would say yes because the skills and knowledge would have been very limited. 'Knowledge' would be simply the basics of survival plus perhaps some simple religious beliefs - our modern man would know far more than his ancient fellows. Manual skills are able to be learned, especially simple ones like tool making, hunting, etc. But could the 40 year old man of 10,000 years ago, transported to today, adequately learn enough to take his place as a smart man of today?

    Let me ask another question that I should have asked earlier. What proof do we have that the brain of today is no different from that of the past? All I have been able to find is that we know the size of the brain by looking at fossil remains. And we can determine that generally speaking, the shape and surface of the ancient brain is not dissimilar to that of today. But what evidence do we have that internally the structures and function were the same?
  16. May 12, 2015 #15


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    It's late here so I'm only going to comment on one of your points: evolve has a very specific meaning in biology and you are posting in a biology sub forum. Please refrain from trying to use it in a broader context as this will inevitably cause misunderstanding.
  17. May 12, 2015 #16


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    Well, that's not correct, so please stop using it. You also don't seem to be willing to understand what everyone is telling you, so I am afraid that this thread is done. If you find an acceptable peer reviewed scientific paper that agrees with you, then you can start a new thread citing that source, but make sure that you read the rules and understand what is acceptable.
  18. May 13, 2015 #17


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    Anatomically modern humans first appeared ~ 200,000 years ago and began spreading throughout the world ~150,000-100,000 years ago. Thus, some of the research into changes in intelligence after this timepoint is controversial because it would have the implication that some populations of humans might be intrinsically more intelligent than others. In the absence of any anatomical evidence, we'd likely have to rely on molecular evidence (i.e. finding signs of recently acquired changes in our DNA) that would suggest changes to the brain. Unfortunately, figuring out how a change in DNA sequence translates to an effect on a complex trait like intelligence is a very difficult task, so while there are some ideas and hypotheses floating around, research has not been able to come to any firm conclusions.

    Many studies have compared DNA sequences across different indigenous populations across the world to look for recent changes to the human genome (see this previous PF discussion), and have indeed found some changes. Many of the changes relate to immunity and probably arose in response to disease. There is also evidence in agrarian societies of adaptations to agriculture, such as the development of lactase persistence in many populations (our humans ancestors were lactose intolerant, and the ability to digest the milk sugar lactose into adulthood is a relatively recent evolutionary innovation).

    There are some published reports that a few genes that could potential modify brain development have changed in recent human history. There are reports that certain variants for the genes for microcephalin and ASPM arose fairly recently (the authors estimate that the changes to ASPM arose as early as ~ 6,000 years ago), and show signatures of positive selection (indicating that the traits are beneficial). However, this research has been challenged as other methods of examining the data do not find signs of positive selection, and comparisons of people with and without the changes do not show any differences in cognitive abilities or brain size. Thus, it seems like these initial reports were false positives.

    Other studies looking for recent changes in the human genome show no obvious signs that would suggest changes in brain development or brain function (though it is worth pointing out that we don't yet understand enough about genetics and neurobiology to confidently say we haven't missed anything), but there remains no molecular evidence that human brain function has changed in recent history. Because it is very difficult to prove a negative, on the basis of the fossil record and DNA evidence, we'll have to accept the null hypothesis that the brain today is no different from that of the past until we can find convincing evidence otherwise.
  19. May 13, 2015 #18
    That's intriguing Ygggdrasil. Thanks for the links, I will have to read that and digest it. Some of what you say goes over my head, especially the molecular/genetic stuff. Not because I don't understand your words but I have little learning of that aspect of the subject.

    However, you are saying (if I read you correctly) that a modern brain appeared around 200,000 years ago. Which is a long time ago. If I use 50,000 years ago as a point of reference, I would be safe to say that the brain of that time is generally understood to be the same as one of today?

    The question of intelligence is tricky as I don't know what one defines as intelligence. From my rather ignorant perspective, I can observe dumb people and smart people. I assume we could say a dumb person is not as 'intelligent' as a smart person. But that is somewhat beside the point of my particular inquiry. I am more interested in the mind and its development and relationship to brain development, but I'll come to that in time if we can work towards that. But perhaps it isn't possible to separate 'mind' from 'intelligence'?
  20. May 13, 2015 #19


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    I disagree. Have you ever made a spear point or stone knife or arrowhead? I can't say that I have, but then I am not saying that these are trivial tasks. They certainly wouldn't be trivial to someone who hasn't done them before. Even if you were able to make a reasonable facsimile of a spearpoint, you need to attach it to a pole it to a staff of some kind. How would you fasten the spearpoint to the staff? What kind of wood should you use for the staff? If you made an arrowhead, you still need to make the shafts to hold the arrowhead, and to fasten the arrowhead somehow? What would you use for the bow itself? For the bowstring?
    And I disagree here as well. The best metaphor I can think of for transporting someone to a time 10,000 years ago would be the situations people find themselves in following plane crashes or car accidents that occur in remote locations, or even hiking trips where the hikers get lost. Many of these people, even those without injuries, are unable to survive long enough to make their way back to civilization.
    "Simply the basics of survival..." and "simple [tasks] like tool making, hunting, etc."
    I don't believe that any expert on survival skills would call such skills "simple."
    Often the timetable for learning those skills is of very short duration -- if you can't figure out how to make a trap or snare or edged weapon fast enough, you might starve to death, or even be killed by a hungry cougar or bear. Survival skills that you wave off so cavalierly have to be learned over many years of practice.

    I sincerely doubt it.
  21. May 13, 2015 #20
    Mark, I am not sure if I can respond to your observations as I have been severely censured for differing with previous comments or offering my own opinions. I would observe that your comments appear to be your own opinions. I don't mean that in an antagonistic way, but do you have evidence to support your claims?

    In saying what I did, I was not suggesting that making a spear point, or affixing it to a stick, is simple to someone who hasn't done it before. That would be a somewhat vacuous claim. Rather, I am suggesting - without evidence it is true - that the mental processes for making a spear are relatively simple by comparison to those required to design and build a jet engine. I think that to be able to design and build a jet engine requires the accumulation of a lot of knowledge and the application of particular modes of thinking/problem solving/conceptualisation that have been developed over many centuries.

    I think that building a spear is relatively simple, and in context would have been easily taught to most members of a tribe. Designing and building a jet not so much. I venture therefore that a primitive man of 40 years of age brought to today's world would struggle to be taught many of the things that people of today can do. Whereas, a reasonably intelligent man of today transported to a time 10,000 years ago would be able to learn all of the necessary skills to survive, if he was supported in doing so. And he probably could learn all of the knowledge that the tribe possessed.
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