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Our future, our universe, and other weighty topics

Friday, November 27, 2015

Can Natural Selection Explain the Human Mind?

We are told that natural selection and random mutations can explain the origin of species, including the human species. But does the concept of natural selection work as an explanation of the human mind? Let us examine some aspects of the human mind, each some way in which the human mind differs from the mind of an ape. Then in regard to each of these aspects let us ask: can we explain this aspect of the mind by assuming that it was something that developed because it increased the reproductive likelihood of humans? If the answer is yes, then we will regard that aspect of the mind as something that might be explained through natural selection. If the answer is no, then we will regard that aspect of the mind as something that cannot be explained through natural selection.

Aspect #1: Man's Aesthetic Capabilities

The first aspect for consideration is the fact that human beings have the ability to appreciate beauty in the world, and the tendency to create new beauty by creating works of art. Can we explain this as something that developed because it made humans more likely to survive until they reproduced? It seems not. Compared to things such as speed, smell, sight, and strength, having the ability to appreciate beauty or create beauty seems to be of no value in increasing an organism's likelihood of having offspring.

In fact, it is easy to think of some reasons why having aesthetic capabilities might be disadvantageous from the standpoint of surviving until reproduction. Show me a caveman who tends to spend time enjoying the beauty of clouds, flowers, sunsets, and starry skies, and I will show you a caveman more likely to be attacked by a predator while he is absorbed in such pursuits – and also a caveman who is probably devoting less time to things like food gathering, which improves his survival chances.

So it seems that we cannot explain this aspect of our humanity using natural selection.

Aspect #2: Man's Ethical Tendencies

The second aspect for consideration is the human tendency to follow codes of ethics. Is this something we can explain through natural selection? One could argue that developing an ethical sense would have made primitive man more likely to survive. For example, if one band of cavemen came into contact with another band of caveman, and both had some kind of ethic of peace and cooperation, it might have been more likely that they would survive.

But you can counteract this argument with another argument just as powerful arguing the opposite. The argument is that a primitive human developing an ethical sense would be less likely to spread his genes about, because he now would feel an inhibition against raping whoever he pleased. Consider a caveman with no sense of morals. He may have felt free to rape whoever he wanted, and that type of conduct is a bonanza from the Darwinian standpoint of spreading your genes around. Make that cavemen a moral person who will not rape, and he will be much less likely to spread his genes about.

So it seems that there is no clear advantage (from a Darwinian natural selection standpoint) to becoming moral. We cannot explain the origin of man's moral sense through natural selection.

Aspect #3: Man's Spiritual Tendencies

The third aspect for consideration is man's spiritual tendencies, his tendency to believe in some higher power. Can we explain this through natural selection? Certainly not. A caveman that develops some spiritual tendency will be no more likely to survive until reproduction than one who has no such tendencies.

Attempts to explain the origin of spirituality through natural selection are typically no better than this very dubious example. The reasoning here is utterly dubious. The author argues that spirituality gave birth to “rules of behavior” that are “necessary to maintain social peace and allow a complex unit consisting of individuals of both sexes and all ages to function in a way ensuring their reproductive success and thus survival.” Not convincing at all, since we don't know whether similar rules of behavior would have arisen without spirituality, and since it is not at all clear that spirituality leads to “social peace” (in the modern Middle East, it seems to be doing no such thing). Also it is not clear that “rules of behavior” will improve reproductive success, because a lawless situation where men rape freely is one where men have a high chance of reproductive success. The author is using here the dubious concept called group selection, which many evolutionary biologists say is invalid.

There is no clear and convincing case that can be made that spirituality has any benefit from the Darwinian standpoint of natural selection and survival of the fittest.

Aspect #4: Man's Mathematical Abilities

The fourth aspect for consideration is man's mathematical abilities. Can we explain these through natural selection? Not at all. Having the ability to do math is something that comes in handy when you are a member of a civilization, but is of no significant value to somebody like a cavemen.

Some of the attempts to explain the origin of mathematical abilities through natural selection are empty “just so” stories typically no better than idle speculation. One such attempt is in the book Radical Evolution by Joel Garreau, where the author speculates that man developed advanced math capabilities because it was helpful when hunting rabbits by throwing rocks. As someone who has actually tried to catch a rabbit in a field, I find such a speculation to be absurd. Rabbits move in unpredictable directions at high speeds, and if early men hunted rabbits with stones, we can presume that they attacked stationary animals – not by calculating the future position of a running rabbit. Throwing ability is something very different from mathematical ability. Early man was not doing math when he threw rocks at things, any more than you are doing math when you shoot some zombies in a video game.

Aspect #5: Man's Musical Abilities

The fifth aspect for consideration is man's musical abilities. Can we explain these through natural selection? Not at all. Musical abilities have no relevance at all to an organism's chance of surviving until reproduction.

Aspect #6: Imagination

The next aspect for consideration is imagination. In this case one could make a case that imagination does have some value from a natural selection standpoint, on the grounds that an imaginative caveman or man-ape would be more likely to imagine his way to the invention of new tools or techniques with a survival value. For example, an imaginative human predecessor would be more likely to first conceive of rubbing sticks to create fire, or to conceive of attaching a sharp rock to a stick to create a spear.

But when we look at the matter deeper, this case weakens. Consider how innovation might have occurred before civilization arose. One individual might have introduced the innovation, which then would have been adopted by the others in the local group. We have an example of such thing in the first scenes of 2001: A Space Odyssey, where one imaginative man-ape figures out how to use a bone as a weapon, and the innovation is then picked by all of the local group. But if we assume that such innovations are passed on from generation to generation, it may be a case where you have only innovator for every 100 or 1000 adopters of the innovation. So it's not clear at all that natural selection can be used here to explain some general increase in imagination.

Let's consider a hypothetical case. Man-ape “Harry” has a chance mutation that gives him more imagination. He then invents some new technique or tool that is picked up by his local group, and maybe passed on to subsequent generations. Harry then flourishes, but he's only one person, and there's only a 50 % chance he will pass on this mutation to his descendants. The fact that Harry's innovation is picked up by lots of others does not mean that they will be more likely to be more imaginative themselves. So scenarios such as this aren't very useful in explaining how imagination could become a general human characteristic (and the very idea of an “imagination mutation” is hard to believe in).

Aspect #7: Insight

One could argue that the development of insight can be explained on a basis of natural selection. One might give a case such as this: if some caveman develops insight that some particular hunting technique isn't working, and the reasons why it isn't working, he may be more likely to switch to some new technique that will be more successful.

But such reasoning isn't convincing. Here is how organisms typically operate when trying to get some result. They try something to achieve some desired result. If what they are doing works, they will stick with that technique. If it doesn't work, they will try something else. This usually works, even though the animal never has any insight into why the unsuccessful attempt doesn't work. For example, a gorilla trying to get a fruit on a tree may try jumping to get it, and if that fails, the gorilla may try shaking the tree branch. The animal never gets, and does not need to get, any insight as to why jumping didn't work.

So it seems that insight doesn't give any tangible advantage that organisms need to survive. We therefore cannot explain the origin of human insight by using natural selection.

Aspect #8: Intellectual Curiosity

Nowadays people display intellectual curiosity by doing things such as reading books, doing web searches, and doing experiments. But how would some caveman have displayed intellectual curiosity? He typically would have displayed intellectual curiosity by physical exploration. But would such exploration have increased the likelihood of reproductive success? Probably not, because before the rise of civilization, physical exploration was extremely dangerous. There are all kinds of ways in which some exploring cave man could die from exploring – dying from the cold, dying from animal attacks, dying from a fall, or dying from exploring some place with too little available water or food. So no clear case can be made that we can explain intellectual curiosity on any grounds of natural selection. Intellectual curiosity is not a biological adaption that helped an organism flourish in its environment, and it is only such adaptions that can be explained through natural selection. 

Exploring what's on the other side of that hill was very dangerous


When we look at the main ways in which the human mind differs from the minds of apes, we find that we cannot explain the characteristics of the human mind through natural selection. Evolutionary biologists will sometimes make statements that come very close to admitting such a thing. If you ask an evolutionary biologist whether Darwinian evolution and natural selection can explain the human mind, such a biologist will typically go into “Darwin defense mode” and claim that the human mind can be explained in such a way. But when writing about the likelihood of intelligence evolving on other planets, some of these biologists (such as Dobzhansky, Mayr and Simpson) said that we should not expect intelligence to evolve elsewhere in the galaxy.  See here for an example. By making such statements, such biologists were inadvertently admitting that natural selection does a very poor job of explaining the human mind. If natural selection did a good job of explaining the human mind, we should expect no evolutionary biologists to say that intelligence is rare in the universe.

The origin of the human mind and human consciousness is one of the deepest mysteries of the universe. We could only explain something so deep by using some very deep principle or principles. But natural selection is not such a principle. Natural selection is instead a very shallow principle, a principle that can be stated in only a few words, words such as “fit stuff proliferates, unfit stuff doesn't.” We should not expect to explain the deep mystery of the origin of the human mind through a principle so shallow, just as we should not expect to explain the deep mystery of the origin of the universe (the Big Bang) by using some shallow principle such as “stuff happens.” 

Postscript: In this post I forgot to mention an additional aspect of our humanity that natural selection cannot explain: our language ability.  While one might be able to explain a tiny-vocabulary language through natural selection, it's hard to explain the development of language with such rich grammar and vocabulary. For a caveman, it's quite sufficient to be able to grunt a few words such as some word meaning "bear." A caveman doesn't need to make statements like, "Heads up, my friends, I think I see a great big bear approaching on the horizon."  Below is the beginning of a relevant blog post by Terrence W.  Deacon:

Since Darwin’s time, the human language capacity has been a perennially cited paragon of extreme complexity that defies the explanatory powers of natural selection. And it is not just critics of Darwinism who have argued that this most distinctive human capacity is problematic. Alfred Russel Wallace—the co-discoverer of natural selection theory and in many ways more of an ultra-Darwinian than Darwin himself—famously argued that the human intellectual capacity which makes language possible, is developed to a level of complexity that far exceeds what is achievable through natural selection alone. 

Postscript: See the link here for a 2-sentence statement signed by hundreds of scientists and PhD's. The statement states exactly the following:
We are skeptical of claims for the ability of random mutation and natural
selection to account for the complexity of life. Careful examination of the
evidence for Darwinian theory should be encouraged.