Visual Intelligence; How We Create What We See by Donald D. Hoffman, W. W. Norton, New York, 2000- A Review

This is a review of the book on visual intelligence written by Prof. Donald D. Hoffman. This review questions the view that we create what we see. It is argued that we rather create a representation of reality. This view is peddled using a discussion around frames of reference.

Few days ago I was sitting on in the first compartment of a stationary train at a busy station. Looking through the windows I could see another stationary train on the adjacent platform. I could only see the train, nothing else, on that side. When I casually looked at the other train after few minutes, I felt very uneasy and almost dizzy. I was overwhelmed by the thought that my train was moving fast even though I couldn’t feel it. My logical faculties were affirming me all along that it was the other train that was moving. But, it seemed like my body didn’t want to believe it. My disbelief perplexed my thinking so much so that I didn’t turn my head to the other side of the train I was sitting on. This is a very real experience about the dissociation between the vision and the signals from the rest of the body. It is also an example about reality challenged by ‘virtual reality’. Something implicit in this example was a voice, however feeble it may be, against reductionism. It is the whole individual who would coax the brain for interpretation, not just the visual cues.

Find the full article here at HUMANITIES COMMONS  (“Humanities Commons is a project of the office of scholarly communication at the Modern Language Association and a trusted, nonprofit network where humanities scholars can create a professional profile, discuss common interests, develop new publications, and share their work.” )

Even though Prof. Hoffman’s book mainly focuses on the way we see the world, it is about the way we perceive the world in general. Prof. Hoffman fills the book with many examples from his wealth of experience, making it a tour de force in a moderately academic context. Thus, the book is not for the feeble minded who want to enjoy a quick and easy read. First six chapters of the book discuss the rules behind the way we see what we see and how we see the movement. With his experience in computing, Prof. Hoffman cannot be faulted for looking for rules to build algorithms usable in vision software. Given the sheer number of rules one wonders why the vision is so complex and overburdened by such a nexus of rules. The examples and rules remind one of the attempts of the proponents of Gestalt Theory to come up with laws to understand figure-ground issue. Here it is good to remind ourselves that figure-ground phenomenon is tied up with ambiguous figures.

The question I struggled with was the inefficiency that can be created by such a complex rule based system. One cannot stop wondering what sort of complex structure of reasoning our genes should construct to see what we see. On the other hand, if we look at the examples Prof. Hoffman gives in the book it is not difficult to see that almost all of the examples are about two dimensional projections of the three dimensional world. As he says on p.23 a two dimensional image showing depth “has countless interpretations in three dimensions.” Should we, then, use such projections and build rules around why the eye interprets ambiguous two dimensional images the way it does? I believe this is more of a way to infuse algorithmic thinking into a process which is less complex in a more pragmatic sense.

As Prof. Hoffman reiterates, we live in a three dimensional world. Our eyes have evolved over long period of time to see the world in three dimensions. If we use the hackneyed argument from adaptationist viewpoint, any creature using vision to live on the earth should protect themselves in a three dimensional environment. Two dimensional images don’t matter much as they occur in a three dimensional background naturally as shadows and silhouettes. Thus, I believe many of the rules described in Prof. Hoffman’s book can be merged to form a simpler structure for three dimensional vision unless we wish to develop computer algorithms.

  1. Phenomenal world we live is three dimensional.
  2. Irrespective of the two dimensional nature of retinal images, our visual systems have been shaped by Nature to live in a three dimensional phenomenal world.
  3. Perception of hues, bundled here with brightness and saturation, and perspective is entrenched in such visual systems.
  4. Over millions of years, eyes have been designed by Nature to look for three dimensional shapes and their defining features.

In my opinion, as an intruder into the realms trodden by experts and academics such as Prof. Hoffman, these are the basic rules which govern our vision. Human eye has not evolved to see the world in two dimensions. All the visual constructions Prof. Hoffman included in his book to show how we create what we see are two dimensional and hence, deceptive to the eye. Thus, I propose we need to be critical as to whether the arguments in the book about Visual Intelligence hold much water in the phenomenal world.

Let us have a look at Fig. 1 below showing white squares on white and black rectangular backgrounds. If you keep looking at them for a while you can see either a tunnel ending in a well-lit space or a flat-topped pyramid. Eye is struggling to create three dimensional visuals with ambiguous two dimensional pictures. Fig. 2 shows grey boxes of two different sizes on black background. Irrespective of what is obvious as figure and ground, both boxes can be seen either as a grey box or a space with two vertical walls and a floor. Why doesn’t this happen with the “attached boxes” of Whitman Richards and Allan Jepson (p.30)? If we ignore the small box for a second we can see two walls attached to a ceiling instead of a floor. But this visual is not sustainable as the small box is not aligned to such a view. It cannot be seen as a similar space attached to a ceiling as the lines guiding the eye are not aligned for both boxes. One box is rectangular in shape while the other is more of a square shaped box.

All of this may tell us something intriguing about our vision. Given Prof. Chomsky’s views about an innate grammar we are all born with, it is not hard to imagine the existence of a visual vocabulary. We all remember that Ancient Egyptians used a language based on pictograms. Modern Chinese still uses logograms representing visual cues. In contrast to these flat-world languages, we may have a built-in visual vocabulary in 3-D which will be called in whenever we see something. As the vocabulary is in three dimensions, finding a meaning for a two dimensional image with ambiguous three dimensional undertones is always difficult. Eye may stretch itself to find meaning in the image. It may change the hue, perspective or movement to try different interpretations.

Fig 1. White square within white and black rectangular backgrounds (See the full article at Humanities Commons)

Fig 2. Grey 3-D boxes in black background(See the full article at Humanities Commons)

Some of the ideas in the book are important in the selection of meaning of such ambiguous images. As Prof. Hoffman says in p.121, our ‘visual intelligence tries to find the lowest cost solutions’. If it can be further interpreted this may mean the most energy efficient and effective solution to a visual problem. Unfortunately, some tricky images with no real existence presented to the eye can be costly and inefficient as the eye had evolved to work with our three dimensional world.

Philosophical Implications of Visual Intelligence and Frames of Reference

Now please forgive me for encroaching the philosophers’ territory. To look at the next chapters of the book, it is necessary to invoke some philosophical musings. Some of the views expressed here are not in agreement with age-old philosophical traditions and thus, are invariably arguable. Unfortunately, these heretical views are required for the following discussion. Prof Hoffman discusses the virtual reality and brain research relevant to our perceptions such as synaesthesia and phantom pain. He also looks at the phenomenal brain and relational brain. Phenomenal brain constructs what we see. But it is present only when we perceive something. On the other hand, relational brain is the one which sustains the object when we are not aware of it. Berkeley attributed this to God who constantly perceives the material world. Prof. Hoffman says he carefully chose the word “construct” to describe the visual process (p.196-7) to avoid mixing the phenomenal and relational aspects. He believes if he uses the word “recover” or “reconstruct” it can mean recovering or reconstructing the forms of objects existing externally through our vision. In my opinion, this reservation arises due to lack of reference to the representational nature of our sensory inputs.

It is more fashionable in current times to explain our mind and our reality in terms of artificial intelligence. In a physicalist world everything is mechanistic. Our brain works like a computer consisting of myriad of binary circuits. Mind is simply physical processes arising from the central nervous system. This may not be far-fetched. But it can only be a science fiction until the immense gap between a modern super computer and the brain becomes more imaginable. No artificial intelligence system has so far passed the long form of imitation game. Even if such a system will pass the test one day, it might be doing it like a person in Searle’s Chinese room.   What about virtual reality? Until we can call a robot a human or at least an early hominid, it may be far-fetched to imagine our reality in terms of virtual reality. Prof. Hoffman doesn’t want to be a part of these arguments and he does this by avoiding the relational aspects of our sensory inputs.

Should or shouldn’t we consider the relational aspect of our perceptions to describe the reality? I believe it is not quite right to say that we construct what we perceive. What we construct is only a ‘representation’. That representation is a result of our senses and our interpretation of the sensory input. If the existential frame of reference tied to the sensory input is compromised by any physical defect, the representation can become ‘particular’ for the frame of reference rather than becoming ‘universal’. Thus, the world and ‘reality’ are about sets of frames of reference. In a relativistic sense, a stationary observer will see something different to a moving observer. But the object that both see, is on its own frame of reference. Thus, all phenomenal and relational existences are relative to specific frames of reference. Reality exists in a relative sense. When I see a tree the representation of the tree I see is subject to a set of frames of reference comprising of two key types. We can use these two key types of frames, namely, existential frame of reference and relational frame of reference in space-time continuum to build a set of frames of reference. I think and thus, I am. This Cartesian view is defined within the co-ordinate system of my existential frame of reference. If I am colour blind, my interpretation of the image of the tree is of a different hue and will become a relational frame of reference that links me with the tree. If someone with normal vision sees the same tree at the same moment, that person will see the colour of tree which is ‘universally’ accepted and will become a relational frame of reference linking that observer with the tree. When none of us are watching, the tree still exists attached to the co-ordinate system determining its existential frame of reference. If the tree ‘can sense’ both of us, it may have two relational frames of reference about being observed. Thus, I believe we don’t create what we see. What we do is constructing a representation of what we see with respect to a set of frames of reference. The objects giving rise to the representations exist independent of relational frames of reference.

Existential Frames of Reference and Berkley’s God

As the above discussion spurs us to think, the world we live in is full of frames of reference. A reality of any animate or inanimate agent is the existential frame of reference attached to its system of co-ordinates. No one can deny its reality as it is independent of any relational frame of reference. Virtual reality created at the Virtual Reality Exhibit described on p.185 has no existential reality independent of the existential and relational frames of reference to the super computer and software. It is like the experience I had on the train. As soon as the computer is turned off or the software running to create the virtual world is closed, the virtual reality ceases to exist. But if the above mentioned tree is moved to a different location, it still exists and the movement traces a series of existential frames of reference in a space-time continuum. Thus, our waking state or ‘life’ in general is not like a dream as Mahayana School of Buddhists would like us to believe in their concept of Vijnapthi Matrata. A dream is more like a virtual reality that we earlier touched upon as the dream depends on the existential frame of reference of the dreamer. Thus, in my view, the reality or the objective world exists if we rein in our unconstrained philosophising. This helps us realise that we do not create what we see. We can replace Berkley’s God with existential frames of reference and experience the existence independent of our sensory inputs.

Prof. Hoffman’s book that I read with great enthusiasm was an interesting journey about ourselves. But it may not be for the travel-weary reader.


Darshi Arachige 5th Sept. 2017


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The Shroud of Turin: Where should Research Lead?

The website you are on is about the coexistence of Science and Religion. The topic of this post is about an object where Science has met Religion or rather Religiosity. The Shroud of Turin has been a very controversial object of veneration. Many devout Christians believe the Shroud to be the authentic cloth which covered the body of Jesus after the crucifixion. Some vehemently reject the Shroud as a Medieval fakery. In spite of the critics, the Shroud stands as a rallying point for the faithful. Without being sure that the Shroud is a fakery from all possible angles, shrugging it off as a fakery after some evidence to support is neither scientific nor reasonable. The paper accessible via the link below is an appeal for a sensible way forward.

ARACHIGE, Darshi. Revisiting the Analysis of 1988 Radiocarbon Dating of the Shroud of Turin. Advances in Social Sciences Research Journal, [S.l.], v. 4, n. 13, july 2017. Available at: <>. Date accessed: 13 july 2017. doi:

This paper looks at the well known analysis of 1988 radiocarbon dating of the Shroud from a new statistical perspective using standard statistical methodologies. The main feature of this paper are embracing of the so-called statistical outliers and considering them as useful information. The major conclusion is that despite the contrary views, the 1988 determinations stand as the most likely given the sampling method used. Thus, research effort should not be wasted on proving that the cause for recent radiocarbon dates was due to the fact that the sample tested in 1988 was contaminated. Research now should be directed at the Shroud as a whole. The paper used the software package R extensively.

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Correcting an Incorrect Reference

In several previous articles and posts published on this website and elsewhere on the internet, this writer  referred to the book “Cave Art” by Jean Clottes with incorrect year of publication.

The correct reference should be:

Clottes, J (2008) Cave Art Phaidon

Sincere apologies for any concerns caused by this.


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Has the Oldest Enigma of Humanity been really solved?

A review of The Oldest Enigma of Humanity: The Key to the Mystery of the Paleolithic Cave Paintings, Bertrand David and Jean-Jacques Lefrère   (Translated by M G Lynch), Arcade Publishing, New York, 2014

I bought the book by Bertrand David and Jean-Jacques Lefrère with keen interest to see how the mystery around Paleolithic Cave Paintings has been solved. The book is small and easy to read. First few chapters of the book are about Mr David’s entry to the subject. I skipped parts of these chapters to get to the content I was eager to read. I found myself to be little disappointed with the way the key idea of the book was argued for. Their idea was simple yet needed supportive evidence. Early people used figurines of animals to cast shadows on the cave walls with the help of the ‘flickering’ flames of lamps. It is known that there is an abundance of animal figurines from the Paleolithic Period. Not only figurines but also the lamps were discovered in these Paleolithic Caves. The authour himself acknowledges the difficulty of producing a traceable image using the suggested technique. “Yet no matter how many times I tried, I never managed to arrive at a helpful rule of thumb that would make it possible to consistently obtain a clear shadow, or even discernible one for that matter”p79.

If making a shadow is such a vexing task, how could the early man do it in a deep dark cave? If the lamps were burning for a long time inside the cave they should have definitely blackened the cave roof. But one can argue that they used a method that was similar to what I used to do as a child to collect the soot from oil lamps. They might have placed a shiny side of a dry bark over the lamp to collect the soot, which they in turn used to draw in black.

The authours claim that when they came up with their idea, they didn’t know about Mr Matt Gatton’s work, which shows some similarities to theirs. According to them, Mr Matt Gatton imagined that camera obscura effect might have created a ‘negative’ image of an animal on a ‘plaquette’ that Paleolithic painters used for creating its ‘positive’ image on the cave wall (p. 111). Mr Matt Gatton in a series of papers (Gatton, M (2010) Pleistocene Coalition News Vol 2 (3) May-June p4-5, Vol 2(4) July-Aug p6-7 and Vol 2(5) Sep-Oct p8-9) explained how an appropriate size of hole on the tent of Paleolithic people could act as a camera obscura (“Paleo-Camera”), which could cast inside the tent an inverted image of an animal lurking outside. This inverted image can be traced on to a surface like a paver stone some examples of which were found in the caves. The image was small and had to be transferred onto the walls of caves via a process of projection somewhat similar to Mr David’s. However, Mr David observes that these drawings on free-standing surfaces are markedly different to the cave paintings in composition. Jean Clottes in his book on cave art agrees and says, in the least in respect of one cave, “the artists who made them [sandstone plaquettes found in Les Trois-Freres] were therefore not the same ones who had access to that cave walls.” (p244 of Cave Art, Phaidon).

Furthermore, Mr Gatton’s idea seems to be somewhat convoluted for the creation of a cave art. Why do someone go through such a process when Mr David’s process is simpler. Animals are always moving and it is very difficult to imagine that they would stay quite until an artist traces the image on to some surface. Mr Gatton and Dr Leah Carreon (Gatton, M and Carreon, L (2012) Pleistocene Coalition News Vol 4 (4) July-August p1-3) uses probabilistic arguments to prove that these ancestors of ours might have seen camera obscura effect at least one per cent of the time in a day (a range of 1-8% per day). The existence of the said effect doesn’t mean a lot because observing camera obscura effect doesn’t prove that these artists used it to create the prehistoric images. On the other hand, I also believe their conclusions are confusing, to say the least. On the basis of the assumptions and deductions used to derive their probabilities they can only draw conclusions about the year not the day. Their sample space for estimating various probabilities about factors such as the weather and dwelling’s exposure to sunlight consists of the year. Thus, one should wonder how  they can interpret their final probability as chances per day. In this light, even the probability of observing a camera obscura effect should be far lower than what Mr Gatton and Dr Carreon believe, i.e. between one to eight times in a 100 year period. In the final analysis, the said probabilities don’t add much value anyway. One imaginative individual with the bright idea was very probably all that was required. The rest could be taken care of by the diffusion of innovation. Even though none of the points in the above discussion prove that Mr David’s approach is better, it makes it equally important contender. In favour of Mr David’s method, we can say that the artist didn’t have to go through the extra step of using the camera obscura effect to create a mobile art. The only trouble with Mr David’s method is adjusting the light to get the image displayed on the wall.

There are some other counter-arguments to the reasoning provided in support of Mr David’s method of creating cave paintings. One such argument is about the relative difficulty of the method in contrast to some easier ones. The early ancestors could have drawn these images on an animal hide in daylight, cut the shapes using their stone implements and used those cutouts to draw the outlines of animals inside the caves. If they had some supernatural theme associated with this practice, it would have been very easy for them to find time to perform the above task. As we know the areas where there was light, were usually avoided by these early painters. They could have done the drawing on an animal hide at the area near the opening of the cave and the finished product might have been carried inside to trace it on to the wall. Perhaps, few people held these cutouts on to the wall and others drew the outline. The painters did not need any extra light at all. Like reading Braille writing, a cutout can be easily traced even if there’s very faint light or no light at all. Let us assume that the pubescent girls lived inside these caves as a ritual practice in Paleolithic period (Reflections on Palaeolithic Cave Art, Girls at Puberty and the Origin of Religion, published in Social Science Research Network – SSRN). They had been secluded and had nothing much to do. They had all the time to draw an image on a hide, cut it out and use it to trace an image inside the cave as a collective activity.

The second argument is concerned with the ease of testing Mr David’s hypothesis. It is easy to reverse-engineer the process and work out what the distances involved and the size of the figurines required to come up with the images on the wall had to be. Did they have enough space inside the caves to do all the manoeuvres needed to get the images right? Such a process will be almost like a definitive proof of the feasibility of Mr Davis’ hypothesis and doesn’t involve all the work discussed in the book as a proof of concept. It seems strange that the authors of the book didn’t use the above scenario to build a strong case for their hypothesis.

Thus, the Oldest Enigma of Humanity sadly is yet to be solved.

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Imagined Orders, Chains of Memories and Biographical Existence: A Brief History of Humankind by Yuval Noah Harrari, Harvill Secker, London 2014

(The following review is also available on-

When people talk about fiction they describe extremely readable fiction as ‘unputdownable’. Dr Harari’s book, though being a non-fiction, is such a unputdownable book. As he says in the acknowledgement, it may be the result of the influence of Diego Olstein who wanted Dr Harari to write a story. Whatever the cause was or whoever the owner of the guiding hand was, reading ‘A Brief History of Humankind’ was a pure pleasure. It was a treasure trove of factual information presented in an absolutely absorbing manner.


Imagined Order

The chapter titled ‘Building Pyramids‘ is one of the most thought provoking chapters in the book. Dr Hararis’ discussion about the imagined order is something I read with great enthusiasm. As he says myths are stronger than anyone could have imagined. As humans we build myths around us; myths about some features marking a territory on the land, myths about heroes who saved the country or the nation and so on. These myths about country, nation, religion and law etcetera are so strong we consider them as causes worthy of even sacrificing our dear lives. The power of imagined order is derived from its inter-subjectivity. Not only an individual believe in the existence of these institutions but also his or her friends and relatives equally believe. Thus, the myths become reality.

I entertain a very similar viewpoint over a long time. Early Indian philosophers of Mahayana Tradition called the world around us ‘Maya’ which is subjective reality or an illusion. They compare it to a dream. At the end of the dream, we are left with a pile of memories, which used to be so real in the dream. I believe each one of us lives in three domains. The essence of Human life is just a chain of memories[1]. Memories are the only factor which runs through the time a person lives. As Heraclitus would say, our physical bodies are in a constant flux. From a person’s point of view, every moment she lives, is a subjective memory. Through these retained memories, the person sees her existence as reality. This is also true in a Cartesian sense. Then, the same person lives in others’ retained memories. These are our objective memories. Thus, objective memories are always an externality. The third aspect is memories about our memories. Here we lose the boundary between objectivity and subjectivity. I may consider an episode from my own dream as a memory. Someone looks at a familiar photograph or recall an incident from the past. That causes a memory of a memory. Dr. Harari’s description of the imagined order is an extension of these memories. We hold the memories about the myths so dear. People around us also do the same. Then, we compare notes through their retained memories and fall in line with the myth. Memories about these memories play havoc in our minds blurring the boundary between reality and myth.

Inverted Pyramid of Memories

Due to these memories, a person lives his or her own life in three different domains. We may call the domain centred on subjective memories autobiographical existence. Then the person lives in other people’s memories or objective memories, which demarcate his or her biographical existence. The third domain is about memories of memories and builds the historical existence. I believe these three domains about our existence build the social order Dr Harari calls “imagined order”. Like genes, in Dr Richard Dawkins’ terms, for our memories the bodies are just vehicles. That is why we inadvertently see history is just the extended existence. Why did I write about the social structures and the structures we build on personal level? What is the relevance? This simply shows that one’s life is an inverted pyramid of memories, which is so fragile and deserves no genuine right to wage war or suppress others on the grounds of the imagined realities. This is not an invitation to a world without war but to a world more introspect and circumspect.

Dr Harai also makes this point very clear in the chapter about Empires – Imperial Visions. He tells us that societies are more complex than what they seem to be. Many a time Empire builders plundered the riches of the subjugated people and laid the land to waste. But then trough the ashes of the old people and culture, another group of people and social structures emerge. Dr Harari provides many examples from the history. But his contribution lies in his argument about reciprocity between the victors and the vanquished. The new orders, which emerge absorb many aspects from both parties. Then after a while the newly emerged societies like the Modern Indians who still adore the remnants of the British Raj, immerse in the new imagined order. New imagined order is not about the forgotten memories. It is all about the retained memories reinforced by the daily experiences. As Dr Harari justifiably points out the modern Indian Nationalists who point fingers towards the havoc caused by the British Occupation, have forgotten that some of the things hold so dear by them are simply the remnants of the old raj. Their fight is about some mixed-up retained memories.

Science and Mathematics

But I regret Dr Harari’s total commitment to the infallibility of Science and Mathematics. However precise these endeavours are they are not infallible. The defence is that science is a learning process based on our acceptance of ignorance. That is very true. But the downside is that science is fast becoming a dogma. We are scared of religion as it prescribes what reality is or should be. We question when a human being from long ago tried to convince that there is a creator God. But no one question us when the physicists insist that the universe resulted from a singularity-destroying Big Bang. Perhaps, as Dr Harari claims, the difference arises from the fact that, we can see no mathematics in the Bible or the Quran. Thus, the religion has no basis to exist. Here, I do not intend to justify religion. But I wonder mathematics is a sufficient and necessary condition to justify a point of view. Wright brothers simply built an aeroplane to prove that man can fly.

I always believe that the languages of Science, namely, Logic and Mathematics, are human inventions and thus, may prove fallible at times. This is not due to the method itself but mainly due to the priories and assumptions on which the method builds on. Thus, there is some likelihood that these too may not be means to absolute truth. On the other hand, there are people who come up with theories with no mathematical arguments. Take Darwin for an example. Apart from Theory of Evolution, he argued that the man had to arise in Africa due to the presence of many big Apes there. As far as modern ideas go, he is right. Another example comes from another biologist. As Prof John Maynard Smith says in ‘Did Darwin get it right?‘, in proposing Selfish Gene Hypothesis, Prof Richard Dawkins didn’t use any mathematics. On the other hand, a very mathematical arguments are not always right. As Prof Roger Penrose points out in the chapter on ‘The quantum particle‘ of ‘The Road to Reality‘ great physicist Schrodinger himself was worried that his equations couldn’t describe the quantum jumps or the state change between particles and waves. Even in case of Statistics, we only see a way of formalising our views of nature. Probability is just an explanation of reality. We only see one realisation of an ensemble of possibilities. We cannot explain why an unbiased coin flip resulted in a Head rather than a Tail at specific point in space and time. We can only talk about the long run outcome. Thus, Mathematics and Logic only can provide a basis to understand the natural world. As we all know, E=mc2 doesn’t tell the universe how the matter and energy should behave. It is just an explanation for the observed behaviour of the matter and energy. But this explanation, for Humankind, opened up a new universe of possibilities.

Thus, in my view, science is just a formalised process to systematically acquire knowledge and mathematics is a universal language to articulate and formalise our views about such knowledge. As Professor Penrose points out with regard to quantum mechanics, the mathematical formalism tells us nothing about an actual quantum reality of the world. Most of us agree that it is wrong and unethical to spread unconfirmed views about the universe and our existence for personal or collective gain; be it religion or science. It is also wrong to subjugate alternative views simply because they do not fall into the accepted fold of ideologies. My view is that it is wrong to subjugate ideas not aligning with my own perspectives by forming schools of thought to exert power and influence. Dr Harari touches upon this point when he talks about research funding. If the ideas are wrong prove them to be so using logic and with same respect and let them die a natural death. Let the science be lit by the spark from the clash of ideas rather than be overshadowed by a gloomy mist of powerful voices and strong prejudices.

I highly recommend this book to anyone interested in understanding who we are and what we have become as a species.

[1] Buddhists would prefer a train of thoughts to a chain of memories. This fleeting existence is momentarily true. But, in retrospect, we only retain our memories about our thoughts.

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A Short Note on Paradoxes Associated with Venus Figurines

The following post now can be downloaded as a pdf file at: Writings on the wall addendum



 In this note few common paradoxes about the Paleolithic figurines and Cave paintings will be discussed and the reconciliation of these seeming paradoxes within the seclusion-of-girls-at-puberty framework will also be explored .



There are some well-known paradoxes surrounding Prehistoric Venus figurines and the cave paintings from the Paleolithic period. A well-known contradiction is about the obesity embodied in the figurines and the actual body shapes of the women who lived in those prehistoric times. Another contradiction is about the inconsistencies between fertility and obesity. Third paradox is about the sites around the dwellings where these figurines were uncovered. Another interesting fact pointed out by the anthropologists is that the Cave artists painted animals that they usually wouldn’t hunt or wish to increase[1]. Are these contradictions insurmountable? This doesn’t seem to be the case when looked at these contradictions in the light of puberty rituals for girls.

Fat Figurines and Slender People

 The figurines depict women who are obese. But in reality, as many scholars believe, “women were fat more in male fantasy than in reality”[2]. The estimate is that less than 25% of women at most were obese[3]. Similarly, it is believed that the women in prehistoric times were relatively slender as they had very active life[4]. It is also said that deducing that the prehistoric women were obese by looking at the figurines is like working out the shape of the modern women through the works of Picasso[5],[6]. Then why do we have the Paleolithic Venuses representing obese females? How can we explain away this paradox? One very plausible answer is offered by the seclusion of girls at puberty. As a practice of initiation the females at puberty were secluded. For an example, via long-term isolation, eating and inactivity, they could have put on weight. One can argue that these figurines were made just as work of art and has no other meaning. But why, then, should these artists and artisans mainly show obese women with no face and no feet? Convergence of all figurines to the above form is very likely to share a deeper meaning.

The fatness of women represented by the figurines is very widely discussed and many authours are quick to point out that the fatness represents fertility. But this poses another contradiction. As Arachige (2009) pointed out previously, the fertility can be adversely affected by fatness and this was known to historic societies at least as evidenced by the historical reference to the fact[7]. In modern medical research, it is known that increasing obesity reduces the fertility[8]. According to these authours, the obesity and the insulin resistance that usually occurs with the onset of excessive fat are associated with various issues such as menstrual dysfunction, anovulation and miscarriages[9].

Another interesting paradox is about the locations these figurines were uncovered. According to scholars these figurines were not discovered inside Paleolithic caves. They were found outside the caves and shelter walls[10]. Were they representing the ones living inside the caves?

Arachige (2015) proposed that the secluding girls at puberty could be associated with the caves. Thus, if the above proposal holds some water, the Venus figurines might be representing the secluded females, perhaps, the special ones. May be they are the women with true shamanic powers or a Goddess associated with the practice of seclusion. This is not a totally ludicrous idea. Note that the analysis of burnt material from the lamps found from the Puits at Lascaux, showed Juniper charcoal and resinous conifer suggesting the early use of perfume burning[11]. This is a significant comment from an archaeologist of renown. Does this indicate the possibility of prolonged staying inside the caves where odour had to be minimized? However, we know that in the caves the people did not engage in daily activities such as cooking and eating[12]. Is this an insurmountable contradiction faced by the idea linking the girls at puberty and Prehistoric Cave Paintings? It is not easy to conclude whether it is or it isn’t. However, it is obvious that the paintings might have taken hours of work. There is evidence that the artists used lamps. The opinion that the artists used scaffolding, at least, at Lascaux is hinting at a long-term stay inside the caves[13]. It may also be possible that the numbers inside the caves never had been large and thus, the middens were not formed. There is also the possibility that the daily refuse were collected and taken out due to hygienic reasons arising from the long-term use of the caves. Burning perfume is a good reminder about their understanding of the acceptable odours, which also indicates their sophistication. There is no reason to believe that even these prehistoric people enjoyed smell of putrid food, especially if the place had some religious underpinning. On the other hand, we don’t know whether food was consumed outside among the rest of the group even though the prolonged stays were allowed inside the caves.

However, in the light of the material discussed in Arachige (2015)[14], the above paradoxes should not be insurmountable to ignore the possibility that the secluded girls at puberty used the caves.

Animal Paintings and Animals for Food

Many scholars wonder why the animals painted by the Paleolithic people and the remains of animals they might have hunted differ[15]. Why should they wish to even increase the population of dangerous animals including felines, which they might not have usually eaten, using sympathetic magic of painting them[16]? Is there really a big contradiction here? From a mere logical perspective, there is no cause for concern. Big cats, horse, bison and mammoth are big animals. If we consider the climate in these prehistoric times, we know Europe was in the last ice age roughly between 10000 years and 100000 years ago. It is deduced using various methods such as ice core data and pollen studies, that the fluctuations of the temperature during the ice age were prevalent. However, near the last Glacial Maximum in Eurasia, people usually lived below the latitude 60 North. The ancestors of modern humans who had to survive temperatures colder than the present occupied area near the Pyrenees Mountains in Europe. The northern Europe suddenly became subject to what is called Bolling warming around 14500 years ago. However, it is only around 10000 year ago, the benign climate took hold in Europe[17]. Cold climate could have made the caves cold too. If the speculation about seclusion of girls inside these caves of some merit, then these cave inhabitants might have been suffering from cold climate harsher than ours. For these girls, heaven would have been one filled with animals whose fur coats and animal fat could provide warmth to their cold-stricken bodies. As we know these Paleolithic people also used animal hides to build their tents. In general, in a cold climate the people might have been more concerned about the warmth as much as the food. This can easily explain why we find big animals whose depiction is more common in those prehistoric caves. The hides last longer and hence the number of animals killed and the remains left behind had to be smaller. Even though modern humans didn’t leave many records to suggest that they hunted big animals as much as Neanderthals did, they also might have loved the larger hides for less stitching they had to do. In this view, Abbé Henri Breuil’s suggestion of sympathetic magic lives on.

Our ancestors might have started drawing much before the cave paintings started. The little kids at the beach today draw with a stick with no guidance from adults. Rudimentary drawing might have come naturally to us as a species. Later, this natural talent might have developed into a sophisticated skill. Like pottery, this could have been the domain of women who would stay back at the dwellings and looked after the children. The Paleolithic people might have used tree barks, animal skins, soft soil or sandy surfaces to draw. This especially true if the cave art had some ritualistic meaning. Due to awe of the unknown, these ancestors of ours might have only allowed proficient artists to draw on the walls. Drawing might have come naturally. The only shift that took place with the emergence of cave art is very likely to be the use of cave walls along with the other surfaces.

As seclusion took hold due to some cultural shift, the secluded women had so much free time on their hands. They might have started drawing animals as a pastime or ritualistic chore. The definitive reason may never be known. As I suggested in a previous post[18] these girls might have drawn the outline of animals on hides and then prepared the cutouts during the daytime at the entrance to the caves or at nighttime in the light of animal fat lamps at the entrance area where there are signs of more habitation. Then the finished product might have been taken inside the cave to trace the outlines. Note the fact that some of the handprints are based on tracing the outlines. Thus, this is not an unknown technique to these prehistoric artists.

As we know from the evidence left, about 12000 years ago, cave art disappeared. One possible reason is the disappearance of the cultural need to seclude girls in caves. Another reason may be the arrival of warmer climate in which the attraction of big animals as providers of warmth became less important. It is unlikely that secluding girls disappeared straight away. But warming climate might have accelerated the gap emerging between seclusion and drawing animals on cave walls.


Even if the modern scholars haven’t acknowledged the possibility of the connection between the Venus figurines, cave paintings and the ritual of secluding pubescent girls, the latter rituals seem to explain away the contradictions as discussed in this note.



Cite this note as:

Arachige, D (2015) A Short Note on Paradoxes Associated with Venus Figurines,


[1] p47, Lewis-Williams, D. (2002) The Mind in the Cave, Thames and Hudson

[2] p343. Guthrie, R. D (2005) The Nature of Paleolithic Art, The University of Chicago Press.

[3] ibid

[4] Trinkaus, E (2005) The Adiposity paradox in the middle Danubian Gravettian, Anthropologie, XLIII/2-3.p263-271

[5] p111. Aczel, A. D (2009) The Cave and The Cathedral, John Wiley and Sons Inc., Hoboken, New Jersey

[6] Leori-Gourhan, A (1967) Treasures of Prehistoric Art, Abrams, New York

[7] For relevant references, see Arachige, D (2009) Paleolithic Venuses and The Puberty Rites,

[8] Mitchell M, Armstrong D.T, Robker R.L, Norman R.J (2005) Adipokines: implications for female fertility and obesity. Reproduction; 130: 583–597

[9] See above.

[10]. p240. Pike-Tay, A (2001) Perigordian, in Encyclopedia of Prehistory, Vol. 4, Europe, ed by P.N. Peregrine and M. Ember, Kluwer Academic/ Plenum Publishers, New York

[11] p43. Scarre, C (1998) Exploring Prehistoric Europe, Oxford University Press

[12] p240. Pike-Tay, A. (2001)

[13] p43. Scarre, C 1998, Exploring Prehistoric Europe, Oxford University Press

[14] Arachige, D (2015) Reflections on Palaeolithic Cave Art, Girls at Puberty and the origin of Religion,

[15] p23 Clottes, J (2008) Cave Art Phaidon

[16] p47, Lewis-Williams, D. (2002) The Mind in the Cave, Thames and Hudson

[17] Chapter 2 and 3, Burroughs, W. J, Climate Change in Prehistory, Cambridge University Press, 2005. Chapter 5, Hoffecker, J.F, A Prehistory of the North, Rutgers University Press, 2005. In Dordogne region were some of the well-known caves are located, people had lived even during the Last Glacial Maximum around 29000 years ago

[18] Has the Oldest Enigma of Humanity been really solved?,, published on 30-05-2016

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The Constructal Law, Feedback Mechanism in Evolution and the Challenge of Selfish Genes – An Opinion

I stepped into a little bookstore to buy a book to read on the train.  The choices were very limited. After tossing a few eye-catching titles up in my mind I finally decided to buy one of them. That book was “Design in Nature” by Adrian Bejan and J. Peder Zane and published by Doubleday, 2012. Undoubtedly, it proved to be one of the most thought provoking books I ever bought. It was about the concept of Constructal Law formulated by Prof. Bejan and colleagues about the limited design choices available in Nature. It took some reading before I could understand what the Constructal Law is all  about. In essence, it tells us that Nature follows the path of energy efficiency and thus, limits the choices available for flow systems. For an example, a fast flow needs a longer path than a slow flow requiring a short distance. Big streams are wide and deep while the small ones are narrow and shallow. Larger athletes swim and run faster. According to the authours, flight of the birds, the running of an athlete and the floating of a swimmer are guided by the same set of rules. Despite broadness of its definition or not having a proper definition for that matter, the Constructal Law encapsulates a very intuitive truth about our daily experiences. Various people using different concepts in the past such as the path of least resistance or maximizing energy efficiency attempted to explain limitation in design choices in Nature. The authours brought all the past explanations under one term Constructal Law.

In many ways, the Constructal Law as stated by the authours can be construed as the Nature’s attempt to balance opposing forces to ensure the most energy efficient path. In case of fast flowing water on the surface, there is a match between the flow and the resistance of the soil. The result is branching off of the original flow. We can call this the path of least resistance. This is not very different from the hierarchies the authours talk about. Social hierarchies represent the dynamic structure imposed by the Nature. One chief needs many subordinates under him or her. Then these subordinates need more people under them for efficient functioning. Large research groups occur in large universities and individual researchers based at small universities would find a balance by moving towards the large groupings (p220).

Unfortunately, I felt that in some situations, the authours tried too hard to fit too many systems into their worldview. For an example, they looked at tree canopies in terms of water uptake by the tree (p.142). This led to their conclusion that the branches of a tree are arranged in a spiral in order to maximize the flow of water. But we can equally argue that it was the maximization of the absorption of sunlight that was far more important to the tree. Sunlight is only available during the day and thus, maximum utilization of it should be logically far more important to the plant than the maximizing water flow which still can happen when there is a humidity potential. Thus, it may not be a matter of flux but a Nature’s way of maximizing energy efficiency.

Even if the Constructal Law exerts its influence on the evolutionary choices, the contingencies Stephen Jay Gould talks about in “Wonderful Life” still applies; the path of the evolution might have taken a different twist despite the fact that the choices are limited by the Constructal Law (p.77). As an example, evolution didn’t have to produce humans. It could have had a different ending depending on alternative set of chances and the evolutionary path chosen.

However, there are few important implications of Constructal Law, which change the way we look at the theory of evolution. According to the authours, all flow systems, over time, should evolve into designs that facilitate their movement (p124). The evolution is about modification in design that has a predictable direction (p102). Thus, at least at an intuitive level, the design constraints imposed by the Nature should have accelerated the evolutionary process. But according to current theory of evolution, the natural selection had to try possibilities the Nature wouldn’t allow. A blind process wouldn’t know until it tried what is allowed and what isn’t. Thus, based on usual arguments, all possible phenotypic expressions of alleles can arise and only the suitable designs can survive. Unfortunately, given the design constraints, this is a very energy-inefficient process. Thus, Constructal Law hints at the possibility of linking a feedback mechanism into Modern Synthesis. As Constructal Law shows, the Nature is trying to do the maximum with the least effort. Nature, in other words, looks for the energy efficient path[1]. Thus, to prevent unnecessary trials and costly errors, Nature has the option of using feedback to confine the selection to a small set of choices. The challenge for us is to find the mechanism underlying such a feedback loop. In higher mammals at least, a feedback loop through conscious selection can happen.

However, the possibility of such a mechanism seems to challenge the selfish- gene hypothesis. The feedback is very unlikely to be conducive to the cause of a gene desperately trying to maximize its chances of survival. The feedback should be about the organism or the vehicle, not the gene or the replicator. As an example, let us use a thought experiment. If an organism is short, all the other features within that organism should work in tandem to provide the overall energy efficiency. But it still has all the genes that produce its taller siblings. Thus, by some conscious process, let us assume that, the shorter mates are preferred by shorter organisms and the gene frequencies drift towards shorter version. So this conscious process of mate selection can be true for many animal species, at least for them, natural selection is not really natural. For an example, human brain development, according to various anthropologists, was impacted by autocatalytic process of mate selection[2]. Thus, the whole organism with its genes working in tandem will be selected. Thus the unit of selection is not one replicator but a collection of replicators working in tandem; rather the vehicle[3] . Design, in short, is a feature of the entire organism not the gene itself as the design by definition in this case applies to the organism or a part thereof. If the design is mal-adapted to the environment, then the organism should go extinct. Thus, the genes also perish. They perish not because they didn’t try to maximise the inclusive fitness via replication but they failed to produce the suitable design for the vehicle by working in tandem. Given the very high possibility of existence of a law limiting the possible choices in flow systems, the organismic view of evolution has the upper hand. Even though Prof. Bejan and colleagues are trying to show none of the views on evolution, apart from the predictability of design choices, shall feel the impact of design constraints, it is somewhat unlikely that they can succeed. But, on the otherhand, why shouldn’t they challenge the modern views on evolution as science only can progress through establishing facts and Laws rather than fighting over theories?

I highly recommend “Design in Nature” by Bejan and Zane for anyone who is interested in reading something stimulating.

[1] This reminds me about my own view of evolution based on energy efficiency. (Appendix , The lure of NOMA, On the elegance of religion, Ocean Publishing, 2009)

[2] See the article on this web site about cranial capacity data

[3] If you are so adamant, you still can argue that it is the gene not the vehicle.


(Also available on-

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Reflections on Palaeolithic Cave Art, Girls at Puberty and the origin of Religion


It is not a stretch of imagination to link seclusion of girls at puberty with the Palaeolithic cave art. The widely accepted view about cave art suggests that the cave artists had been shamans. This shamanic origin can imply that the religion emerged in the times when the cave artists were active. It has already been posited in the relevant literature that the Venus figurines representing mobile art of the period suggests their connection to the rites of girls at puberty. This paper explores the possibility that there could have been a link between the cave artists and the girls at puberty. This connection means that the religion might have started with an association to the girls’ puberty rites.

( Download the pdf version here: Writings on the wall v31)


Seclusion of girls at puberty had been discussed by several authours including Frazer (1993)[1], Benedict (1934)[2], Richards (1962) [3] and Lincoln (1981) [4]. However, apart from Frazer, the other authours mainly looked at anthropological importance of this rite of passage. Arachige (2009)[5] discussed the possible significance of these rites to the origin of religions. Even though on its face value this may seem as a long shot, in a previous article Arachige (2010)[6] suggested that there could well be a link between the seclusion of girls at puberty and the Palaeolithic Venus figurines. Arachige (2009, 2012) [7] also argued that the seclusion of girls could have been practised at least 40,000 years as the spread of the motifs of seclusion on a geospatial basis indicates. This opens up the possibility of a substantial continuity of the said puberty rites since the Palaeolithic times[8]. If such continuity can be established, then, finding the roots of religion, as our today’s perspectives on religion allow us to believe, in the seclusion does not seem far-fetched. Arachige (2011)[9] also hypothesised that the seclusion rites related to the Venus figurines might have branched off to other cultural traits in prehistoric Europe. In the present article, it is intended to bring together some of these ideas to form a foundation for a more cohesive hypothesis about the origin of religion.

Road to Religion via Puberty Rites

There is the widely accepted view of the existence of prehistoric shamanism as evidenced by Palaeolithic cave art. All prominent authors in this school, Lewis-Williams, Whitley (2009)[10], Clottes (2011)[11] have discussed this point of view in detail. If it can be shown that there is a connection between the prehistoric art, shamanism and the puberty rites, then, it is not difficult to take the next step of identifying the nexus between religion and girls’ puberty rites.

When it comes to religion, a mechanistic framework with parallels to what is expounded by behaviourist school in psychology is so widespread among anthropological community as evidenced by the following comments of Atran[12] about the supernatural agency. “In all cultures, supernatural agents are readily conjured up”. The reason for this is that “natural selection has trip-wired cognitive schema” to detect external agents. This is more so because of the uncertainty associated with  detecting danger. This impact of uncertainty results in a “hair-triggering of an agency-detection mechanism” lending “itself to supernatural interpretation.” However, the existence of the supernatural is a universal cultural norm and its association to religion is widely accepted.

There are many different views about the origin of religion. Again, according to Atran (2002)[13] religion can be defined as  a community’s costly and hard-to-fake commitment to a counterfactual and counterintuitive world of supernatural agents who master people’s existential anxieties, such as death and deception[14]. The crux of the above definition is the involvement of supernatural agency in religion. The idea of such an agency is minimally counter-intuitive and thus, could take root in our psyche. As the puberty rites and idea of the perceived supernatural abilities of the girls at puberty is so entwined in the minds of many societies that it would seem very worldly, the connection between religion and seclusion of the girls at puberty becomes an overarching possibility. It can be posited that the supernatural agency was not necessarily something conjured up by our cognitive system developed through natural selection. The origin of the religion can be more mundane.  No one would call Darwinism or the Theory of Relativity was a product of natural selection. Despite the fact that we can laboriously find an argument to prove the hand of natural selection, two key individuals conceived these ideas through their gift for synthesis.  Similarly, some gifted individuals had some abilities, which others perceived as extraordinary. A series of behaviours, which resulted from such beliefs, gave rise to the belief in the supernatural among our prehistoric ancestors.

Furthermore, the present author believes that the above cognitive explanation is an attempt to see the religion in a Darwinian perspective in the hope that being able to conceptualize such an agency-detection mechanism and its probable connection to the existence of the supernatural alone can justify such a theory. But let us question how we know that such a universal mechanism can lead people to follow a focal person as we usually encounter in many religions and cults. In other words, how can we explain the specificity through universality, i.e. many followers one founder? In any shamanic culture, all members thus trip-wired by the natural selection would not end up as shamans. Given the status accorded to girls at puberty in early history where written records exist[15], it is very probable that in the prehistoric times too, girls at puberty had also been considered to be “special people”.  It is interesting to note the mention Whitely makes about the girls’ puberty rites in the community of Luseno Indians in southern California.  The young girls at the conclusion of their puberty rites painted their spirit helpers and left hand prints usually in red[16].  As Boas tells us in his book, “The Mind of Primitive Man”, cultural traits such as the above, which “occur sporadically in regions far apart”, should be carefully interpreted to deduce their continuity without change in various cultures from the prehistoric times[17].

The puberty rites in various parts of the world continued to involve the seclusion and the belief of special powers of the girls at puberty. Sir James Frazer treated this liminal state, which placed such girls between heaven (not to see the sun) and earth (not to touch the ground). However, many researchers for various reasons would like to avoid discussing the supernatural aspect of these rites of passage. This attitude reminds of the behaviourist school of psychology, which ignored all subjective concepts not directly observable[18]. However, there had always been a deep involvement of supernatural factors in the life of a girl at puberty, which had been discussed in detail in another article[19]. Even though all girls at puberty can have the potential to become shamans, the current proposition about the girls at puberty being associated with the origin of religion doesn’t require them all to be ‘special persons’. Some of them can always be special due to their special qualities; the rest, perhaps, their retinue. This can be further discussed in the background of possible connection between the founders of religion and their abnormal psychological conditions[20]. Many founders of religions were considered by their contemporaries to have special powers.

One major reason for the attitude of separating the supernatural aspect from the girls’ puberty rites is the presence of puberty rites for boys, which are mainly rites of passage. For girls, there is more to puberty rites than mere celebration of a rite of passage. The perception that considering supernatural explanations is not scientific can be a very daunting factor for the scholastic community. Growing up in a place and time which now seem like a time capsule of cultural traits made the current authour realise how important the supernatural aspect was for the seclusion of pubescent girls (see also De Silva, 1981)[21]. Young girls were instructed not to eat certain oily food and not to wonder about alone in fear of being possessed (Arachige, 2011). When they walk about alone, they were asked to take a piece of iron or something made out of iron (De Silva, 1981; Narayan et al, 2001)[22]. The girls were feared because of ‘bad energy’, carried by them. Unless we are not ready to think like the people whom we are studying or consider the most significant aspects, if not one of the most significant aspects, of their cultural practices, we are throwing out key phenomenological content of our investigations. This may mean being blind to the facts in order to be scientifically acceptable. In the ensuing discussion, I would like to mainly focus on the ‘magical’ world where people whose minds were not affected by the idea of modern day scientific rationalism.

Palaeolithic Shamans, Religion and Cave Art

According to the most widely accepted view of the Palaeolithic art, early shamanic practice can arguably be related to the origin of the earliest-known cave drawings. According to Lewis-Williams (1997)[23], both representational and geometric image making in the Palaeolithic period was done by early shamans in an altered state of consciousness induced, perhaps, by psychedelic plant material. Oxford Dictionary defines shaman as “a person regarded as having access to, and influence in, the world of good and evil spirits.” After accepting that the Palaeolithic cave artists were prehistoric shamans, Whitley (2009) argues the case for the association between religion and cave art. He proposes that the shamanic ecstasy as promoted by Mircea Eliade is a myth and the shamans are generally suffering from affective disorders ranging from minor depression to schizoaffective disorders. He believes that given the human nature conditioned by our evolutionary history and cognitive development, as discussed in preceding paragraphs, religion arose from already present cognitive roots through organization of beliefs in prehistoric western Europe. Note the importance of a natural cause to this prehistoric form of shamanism.

In the light of recorded connection between perceived supernatural abilities such as negative impact of the evil eye or touch and the girls at puberty it can be deduced that in the periods prior to the written history girls at puberty were deemed to have suffered from some psychological conditions, which were perceived by others as either as detrimental or beneficial to the community depending on the circumstances and perspectives. These traditions persisted to the historical times after losing its original context. It seems that valuable contributions by them as people with psychic abilities were possibly undermined by the later traditions.

It is interesting to note that in case of unipolar depressive disorder, one of the mood disorders Whitely mentions, there is a well-established gender difference[24] observed in many countries around the world[25]. A WHO Report also mentions that[26]

Despite later onset, some studies report that women experience a higher frequency of hallucinations or more positive psychotic symptoms than men (Lindamer et al. 1999)[27]. Similarly, while the population prevalence rates of bipolar disorder appear not to differ, gender differences occur in the course of the illness. Women are more likely to develop the rapid cycling form of the illness, exhibit more comorbidity (Leibenluft, 1997)[28] and have a greater likelihood of being hospitalized during the manic phase of the disorder (Hendrick, Altschuler, Gitlin et al. 2000)[29].”

Major mood disorders show some major gender differences and the females are susceptible to it at roughly twice the rate of the males[30]. Thus, if the affective disorders helped the emergence of shamans in the Palaeolithic times, the most of them had to be females. As mental diseases cannot be totally stripped off the cultural context, it is not sure how gender bias played its role in those prehistoric times. In historic times, it was the female of the species who communicated with the supernatural[31] or had physical contact[32] with it. As Scientific American puts it, “Extraordinarily for misogynist Greece, the Pythia was a woman and ……the Pythia did not inherit her office through noble family connections.”[33]. Even if an ordinary person smelled the pneuma, the gas arising from a cavern deep down in the earth, which sent the Pythia to her trance, that person didn’t go into the oracular trance. So the Phythia was special. In prehistoric times, this could have been even more prominent and the dark, deep Palaeolithic caves might have served the prehistoric Phythias well[34]. This same misogynist attitude might have left the girls at puberty with only the evil influences. Given the prevalence of female figurine in the Palaeolithic times, it is probable that the women were stripped off their due recognition after an early acceptance.

Shamanic Powers in Women

In the Palaeolithic times, it is believed that the hunter-gatherers roamed the Earth. From observing the hunter gatherer communities which persisted to more recent times, Anthropologists believe that due to the commitment to care and carry the young and the time taken to become a skilful hunter, for women, hunting which provides a high quality diet is not profitable[35]. Usually, women, children and grand children in foraging societies collect plants, shellfish and insects[36]. Thus, women should have had more knowledge about the vegetation that could be consumed and their specific qualities. If this argument extended, it can be easily seen that they had the best opportunity to see which plants were psychedelic and which were edible herbs. Thus, the first shamans, even if they were dependent on such psychedelic plant material, were more likely to be females of the clan. However, women might have had a natural inclination to portray extraordinary behaviours in the minds of the ancients through the perceptions about their puberty. The special treatment attributed to prehistoric women can be further corroborated by the skeletal remains of a woman considered to be a shaman and discovered at Dolni’ Vestonice in eastern Europe[37].

As was discussed by many authours, the place of the female as a person who is supernaturally gifted has been recorded in so many ways. Even though the period referred to by these authours is more recent, the attitudes might have persisted from the Palaeolithic times. One recorded example comes from the studies on trepanning undertaken by the famous Paul Broca and his contemporaries. It is an uncanny tribute to Broca’s brilliance to get an area of the human brain named after him. After studying the skulls from Neolithic Period it was Broca who proposed that the trepanning was performed to cure illnesses such as epileptic seizures. Trepanning, according to him, was done when the patient was young. If the patient withstood the ordeal and survived, then, at death, amulets were made out of such trepanned skulls and were used as a prophylactic against all other diseases[38].  Almost half of the skulls found were females. Contrast the practice of such after-death veneration of the body parts or other aspects of the dead personalities with our belief in the influences of many founders of religion, the Son of God, gods and goddesses or Saints who are not physically present among us. After ignoring the specialities, at least in the spirit of the action, all these have underlying interactions. It also is interesting to note that a special case called T Sincipital was almost exclusive to female skulls[39]. The view is that this procedure was a result of a religious ritual performed over many years.

Given the major emphasis of the puberty rites are on the rather sinister aspect of the supposed supernatural powers of the girls, it is difficult to see how this could have led to admiration which is common in a religious inspiration. The answer can be twofold. The girls were mainly adored for their ability to punish the enemies, who had to be many given the competition for the limited resources. Punishing enemies is a tradition, which continued to Roman Period in Europe[40]. As an example, written evidence was discovered at the temple of Goddess Minerva at Roman Baths in Bath, England, asking her help to curse their enemies[41]. Similarly, it was the statue of a goddess Artemis at Pallenne the gaze of which could be detrimental[42].  Also note that Lincoln[43] considers the Persephone myth is also associated with the puberty rite of seclusion. Persephone and Demeter are the mythic characters associated with the Eleusinian Mysteries in Ancient Greece. This connection between the goddesses and the puberty rites arguably going back to Minoan Civilization of ca. 2000 BC[44], also accentuates the religious tendencies associated with the girls’ puberty. The other possibility is a later revisionist attitude to only focus on the harmful side of their perceived abilities. This can very well be the case as the girls at puberty in Umnak Island were considered as having healing powers and her saliva was used to treat rheumatism[45]. Apache Indians also considered the girls at puberty as a source of supernatural blessing[46].  It is human to shift the focus depending on the prevalent cultural whims. The discovery of psychedelic plants can be such a turning point, which later helped more men to acquire supernatural or shamanic powers. Over time, the power struggle between male and female shamans could have turned the scales in favour of the male shaman. Female shaman who lost her prominent place could not be totally replaced due to her natural gift of “supernatural powers” and continued in the roles like that of the Phythia.

Role Played By the Caves in Puberty Rites

The research done by Sharpe and colleagues, point out that in Rouffignac Cave, out of seven fluters five were women and girls some of whom were only about five years old[47]. These authours also point out that the shamanic hypothesis of Lewis-Williams brakes down as the fluters had to have poked the fingers in instead of fluting the surface, had they tried to get closer to the sacred world lying behind the walls. Furthermore, some fluters were children, who were unlikely to have performed as shamans[48],[49]. Similarly, the analysis of the measurements done on the hand stencils found in El Castilo in Spain and France and Gargas and Pech Merle Caves in France showed a majority to be female hand stencils (about 75%) [50],[51].  This doesn’t prove us that these females were kept in the caves or we can have complete faith on the soundness of the analytical basis of such investigations. But it is not simply a heightened state of imagination. (Clottes, 2011) after many years of researching the caves writes that given the abundance of female motifs in caves, the prehistoric people might have thought the caves to be female[52]. Add this to the female behinds and pubic regions depicted in these caves. Presence of many female contours without heads and feet can be perceived as girls or women sleeping on the side[53]. Gimbutas discussed the “reclining women” found sculpted in relief in the cave of La Madeleine with one arm and both legs upraised[54].  Gimbutas assumed these women were in labour. But, if they were in labour, wouldn’t they be known as “women in labour” rather than “reclining women”? Isn’t the first impression rather than a laboured interpretation more close to the truth? On the other hand, what facts do we have to confirm the birthing practices in prehistoric times were similar to ours? It is well known that both reclining and squatting birthing positions are practised even in modern times. Thus, these women we meet in the La Madeleine Cave can well be reclining and someone else depicted them on the walls. It can well be other women with more skilful hands and imagination who depicted their fellow inmates in such a manner. Also note that another reclining woman opposite a sorcerer was depicted in Gabillou Cave in Dordogne, France. This woman, also without a head was described by Clottes[55]. He also described another reclining female figure in low relief on rock of La Magdelaine des Albis Cave in Tarn, France[56]. Clottes (2011) mention that the female genitals or typically the pubic triangles[57] were represented in European cave art from the Aurignacian on, as the caves were perhaps thought as female[58]. It may well be the case these were drawn by women to mark their territory or just to get rid of boredom. The point is that some libidinous male occupants of the cave did not necessarily do these markings.  It is a possibility that these artists lived in those caves for some span of time[59] when we are look at “seclusion huts” with many women[60].

And consider the time taken to get the eyes accustomed to the environment inside a dark cave[61]. If the person lives in the cave for some time, it would be easy for the person to get used to the darkness and do many things by the flicker of a lamp. If the oil lamps were burning all the time the drawings were done, there could have been more carbon dioxide inside the cave making long stays very uncomfortable. On the other hand, burning fat had to blacken the cave roof badly. Similar arguments might help us to believe that the persons who drew on the Palaeolithic cave walls stayed in these caves long enough to get their eyes accustomed to the darkness.

There can also be a supernatural aspect to this. The women hidden in those deep dark caves might have been expected to see without seeing and walk without walking. In these early days, they were expected to see whether the herds of bison or mammoths would come to their vicinity soon; walk to the places where their enemy tribes lived; see the future for the Elders or travel to places where the dead souls of the ancestors roamed[62]. The human nature across the globe when all the trappings, which the culture and socio-economic landscape imposed on it, are peeled off is similar. Diamond[63] vividly explained this about intelligence and civilization. In the prehistoric times all human beings might have thought about various aspects of their lives in a similar light. Frazer[64], Lang[65] and Bastian[66] collected a large number of examples about rituals of primitive people to prove this same fundamental similarity arising from independent development through the psychic unity of mankind. Thus, when removed from the cultural aspects, the rituals and beliefs surrounding the girls’ puberty can show us that the maidens were thought to have special powers to see without seeing and travel without travelling. In the minds of the ancients, there was no place for mental illnesses as they might have thought about these as the afflictions caused by a dead relative or a communication with gods or goddesses. Jaynes[67] describes many examples on how all humans before the breakdown of bicameral mind[68] thought about them as conversing with the gods. A lone mental patient had been easily drowned in such a population-wide phenomenon. The important point is that for our prehistoric ancestors, the voices heard and visions seen through a mental illness could have been mere expression of external agency, not perceived to be ailments. Thus, any mental illness suffered by some adolescent girls due to various socio-cultural factors[69] was very likely to be attributed to the external factors, which we call supernatural. This can be well within the sphere of shamanism. In another article, the special place of women in shamanic practices was discussed by the present authour[70]. Thus, it is very probable that the cave dwelling women were supposed to perform a special task for the clan.

Concluding Remarks

One major point, current author considers with some reservations is the reality of “Creative Explosion” which took place in the Palaeolithic times about 40,000 years ago. How could we be so certain that long before the humans drew on cave walls they didn’t draw on sand, bark or rock which disappeared in the passage of time? How could we be so certain that for ages they had a taboo imposed on them not to represent the nature in any other form? How could we be sure some new socio-cultural change didn’t lead them to see the animate and inanimate world around them in a different light? As the archaeological findings show, our ancestors had used shells, indicating their ability to grasp symbolism, at least 50,000 years earlier than previously thought[71]. Could the cave art, thus, be the product of a cultural revolution rather than a creative explosion?

Whatever the reasons for the emergence of both mobile and parietal art in the Palaeolithic Europe were, it is very probable what we see today could be due to a system of thinking involving the supernatural abilities of the players in this drama. Scholars proposing the shamanic practices as the cause of cave art as well as the ones suggesting the involvement of mental disorders are trying to uncover an abnormality such as hallucinations to trigger the action. Some even proposed the mind of these ancient artists showed some limitations, which were evident in autistic people before they acquire language skills[72]. In summary, the current prevalent thinking places the importance on some form of abnormality of the prehistoric person. The proposition explained in the present article is not contradicted by the role played by perceived abnormalities of the girls at puberty. These perceived abnormalities were bordering on the supernatural abilities attributable to external agency in modern parlance. Think of the belief that a simple look from a girl at puberty could make weather turn bad[73]. In the mind of the our prehistoric relatives, she could be treated among those with shamanic powers. It is interesting to note that the gender of shamans was not just male. There is evidence as given in the preceding sections that the majority or equal proportion of shamanic practitioners could have been females. There could have been a significant impact of girls at puberty on the population of shamans or the future shamans as the persistence of puberty rites very similar in symbolism prevailed over time and space. If the religion was shamanic in origin, the contribution of the girls at puberty should be very substantial as many artefacts representing the prehistoric Venuses can be thought of as associated with the pubertal rites of girls in their origin.



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Arachige, D (2015) Reflections on Palaeolithic Cave Art, Girls at Puberty and the origin of Religion,



[1] Frazer, J 1993 (1922) The golden bough: A study in magic and religion, Wordsworth Reference, Ware

[2] Benedict, R 2005 (1934) The patterns of culture, Mariner Books, New York

[3] Richards, A. I 1982 Chisungu: A Girl’s Initiation Ceremony among the Bemba of Zambia, Routledge, London

[4] Lincoln, B 1981 Emerging From The Chrysalis, Studies in Rituals of Women’s Initiation, Harvard University Press

[5] Arachige, D 2009 The lure of noma: on the elegance of religion, Ocean Publishing, Perth

[6] Arachige, D 2010 Prehistoric Venuses and Puberty Rite,

[7] See 5 above and Arachige, D 2012 Antiquity of Secluding Girls at Puberty. Available at SSRN: or

[8] p. 10-21. Froese, T. 2013 Altered States and the Prehistoric Ritualisation of the Modern Human Mind. In: C. Adams, A. Waldstein, B. Sessa, D. Luke & D. King (eds.), Breaking Convention: Essays on Psychedelic Consciousness, London, UK: Strange Attractor Press

[9] Arachige, D 2011 Witches, Shamans and the Girls at Puberty. Available at:

[10] Chapter 7. Whitley, David. S. 2009. Cave paintings and the human spirit, Prometheus Books, New York (Kindle Edition)

[11] p24-25. Clottes, J 2011 Cave Art, Phaidon, Reprint

[12] p71. Atran, S 2002 In Gods we trust: The evolutionary landscape of religion, Oxford University Press, New York

[13] p4. ibid.

[14] The existence of the “supernatural agent” is even more prevalent in modern science. For an example, Charles Darwin is treated as the great genius, who discovered evolution “for the first time”. For many great biologists, he is almost the supernatural genius who deposed God. This exemplifies how human behaviour accords people who stand above others in the eyes of the majority a ‘supernatural’ status and gathers followers.  Thus, a following doesn’t ensue from an ordinary person. A focal person, a Transcendental Social like an Elder from a tribe, a celebrity can only gather people around them. Any person deemed not to be special cannot be different to the rest in the eyes of the ordinary people and thus, is not worthy of a following. The present author discussed some of these ideas in the chapter 3 of “The Lure of NOMA”, (Arachige 2009)

[15] Pliny. The Natural History. Quoted on p606.  Frazer, J 1993 (1922) The golden bough: A study in magic and religion, Wordsworth Reference, Ware

[16] Chapter 4. Whitley, D. S 2009 Cave paintings and the human spirit, Prometheus Books, New York (Kindle Edition)

[17] Chapter 9. “Early Cultural Traits” in Franz, B 1938. The Mind of Primitive Man, The Macmillan Company, New York

[18] p63. Fromm, E 1973 The Anatomy of Human Destructiveness, Pimlico, London

[19] Arachige, D 2010 Prehistoric Venuses and Puberty Rite,

[20] Chapter 3. Arachige, D 2009 The lure of noma: on the elegance of religion, Ocean Publishing, Perth

[21] p35-36. De Silva, D W 1981 Puberty rites for the Sinhalese female. Lambda Alpha Journal of Man, 13. Available at:

[22] p225-238. Narayan, K.A, D.K. Srinivasa, P.J. Pelto and S. Veerammal 2001 Puberty rituals, reproductive knowledge and health of adolescent schoolgirls in South India, Asia-Pacific Population Journal 16(2).

[23] p321-342. Lewis-Williams, J. D 1997 Harnessing the Brain: Vision and Shamanism in Upper

Palaeolithic Western Europe, in Beyond Art: Pleistocene Image and Symbol, Proceedings of a Paul L. and Phyllis Wattis Foundation Endowment Symposium, ed. by Margaret W. Conkey, Olga Soffer, Deborah Stratmann & Nina C Jablonski, Wattis Symposium Series in Anthropology, Memoirs of the California Academy of Sciences, No. 23, University of California Press, California

[24] World Health Organization, Gender disparities and mental health, Retrieved on 9 July 2015. Available at:

[25] p248-249. Carson R. C, Butcher, J. N, Mineka, S and Hooley, J.M 2007 Abnormal Psychology, 13th Edition, Pearson, New Delhi

[26] Psychologist Julian Jaynes believe that it is easier for women to become oracles, as their brains are less localized than those of men. p344. Jaynes, J 1990 The Origin of Consciousness in the breakdown of the bicameral mind, Penguin, London

[27] p61-67. Lindamer, L.A et al 1999 Gender-related clinical differences in older patients with schizophrenia. Journal of Clinical Psychiatry, 60

[28] p163-173. Leibenluft, E 1997 Women with bipolar illness: clinical and research issues. American Journal of Psychiatry, (153)

[29] p393-396. Hendrick V, Altshuler L.L, and M.J. Gitlin et al 2000 Gender and bipolar illness. Journal of Clinical Psychiatry, (61)

[30] p675-689. Pitychoutis P.M, Papadopoulou-Daifoti, Z 2010 Of depression and immunity: does sex matter? The International Journal of Neuropsychopharmacology, 13

[31] See the historical reports on Pythia, Cybills etc.

[32] Herodotus, Book 1.181-182

[33] Hale J. R., de Boer J. Z, Chanton J. P and H. A. Spiller 2003 Questioning the Delphic Oralce, Scientific American

[34] Many authours including Lewis-Williams and Wheatley finds the air quality within the Palaeolithic caves to be poor.

[35] p156-185. Kaplan H, Hill K, Lancaster J, Hurtado, A. M, 2000 A theory of human life history evolution: Diet, intelligence, and longevity, Evolutionary Anthropology, 9:4

[36] However, according to some authours, this formulation also based on observing the present day societies, suffers from lack of direct evidence as much as the other view of larger participation of the female in hunting.  See p.82 of Adovasio J.M, Soffer, O and Page J 2007. The Invisible Sex, Smithsonian Books, Ney York

[37] Tedlock, B 2005 The woman in the shaman’s body: Reclaiming the Feminine in Religion and Medicine, Batman, NY (Kindle Edition)

[38] p223-228. Munro, R. 1897 Prehistoric Problems, William Blackwood and Sons, available at

[39] p236-238. See above publication.

[40] Even in recent past, in Sri Lanka, there were people who were highly admired for their ability to write poetic curses, cast black magical spell on someone’s enemies. These same people could do the exact opposite when asked by a client.

[41] See (Retrieved on 27 July 2015)

[42] p131. Ginzburg, C 1992 Ecstasies: Deciphering the witches’ Sabbath, Penguin Books, London

[43] p71-90. Lincoln, B 1981 Emerging From The Chrysalis, Studies in Rituals of Women’s Initiation, Harvard University Press

[44] p75. ibid.

[45] “During this time the girl is believed to have healing powers. An old man with rheumatism was brought to the author’s informant during her confinement so that she could rub his aching knees with her saliva, which is said to have stopped the pain.”-p145-148. Shade, C. I 1953 The Girls’ Puberty Ceremony of Umnak, Aleutian Islands, American Anthropologist, 53(1). Available at

[46] p22.  Benedict, R 2002 The Diversity of CulturesCultural Sociology ed. by Lyn Spillman. Blackwell Publishers Ltd.

[47] p937-947. Sharpe, K & Van Gelder, L 2008 Women and girls as Upper Paleolithic Cave ‘Artists’: Deciphering the sexes of finger fluters in Rouffignac Cave. Available at; Sharpe, K & Van Gelder, L. 2006 Evidence for Cave Marking by Paleolithic Children. Antiquity 80:310.

[48] Sharpe, K & Van Gelder, L. 2006 a Human Uniqueness and Upper Paleolithic ‘Art’: An Arachaelogist’s reaction to Wentzel Van Huyssteen’s Gifford Lectures. Available at

[49] Cambridge Archaeologist Jess Clooney proposed through her research the most prolific fluters in in Rouffignac Cave was a three-year-old female child. retrieved on 27 July 2015

[50] The article published in National Geographic News on 16 June 2009. “Prehistoric European Cave Artists Were Female”, at

[51] p746-761. Snow, D 2013 Sexual Dimorphism in European Upper Paleolithic Cave Art, American Antiquity, Number 4 / October 2013, (16). Available at

[52] p147. Clottes, J 2011 Cave Art, Phaidon, Reprint

[53] p214-215. Also see p218. Note that there is more than one such silhouette in the same place. Clottes, J 2011 Cave Art, Phaidon, Reprint

[54] p105. Gimbutas, M. 1991 The Language of The Godess, HarperSanFrancisco

[55] p124. Clottes, J 2011. Cave Art, Phaidon, Reprint

[56] p262. ibid

[57] The pubic triangle is the popular belief about these motifs. Arachige questioning this interpretation in one blog post asks whether these triangles can be thought of as motifs representing chastity or promises of chastity or a chastity belt (see Or it may also be a motif for menstrual women or the pubertal girls.

[58] p147 and p255. ibid

[59] The paper mentioned below hints at an interesting possibility that Bolombas cave being a place associated with the girls’ seclusion as the presence of red ochre suggests, despite being a weak argument to connect the two. p.10-21. Froese, T. 2013 Altered States and the Prehistoric Ritualisation of the Modern Human Mind. In: C. Adams, A. Waldstein, B. Sessa, D. Luke & D. King (eds.), Breaking Convention: Essays on Psychedelic Consciousness, London, UK: Strange Attractor Press.

[60] DuPlooy, S 2006 Female initiation: becoming a woman among the Basotho, M.Sc.Sc Thesis, Department of Anthropology, the University of the Free State, South Africa (available at

[61] Note that the 19th century scholars didn’t want to believe that prehistoric people due to the darkness inside these caves did the cave art. Only after the discovery of sandstone lamps inside the caves, they decided to accept the view.

[62] In the place, the present author grew up young maidens who were not bitten by a dog were sought after by the shamans. Such women were supposed to have some shamanic powers.  At night after a series of ritualistic chants, these maidens were supposed to divine with a blackened surface of a saucer on which a flicker of an oil lamp danced. Not every such maiden could perform the task. Some women were supposed to have an innate ability. They were supposed to seek help from Hanuman, the Hindu Monkey God, or Anjanam Devi (Goddess of Anjanam) in their psychic travels. Hanuman or Anjanam Devi was supposed to take the seeker to places so that she could perform her tasks.

[63] p15-32. Diamond, J 2005 Guns, Germs and Steel, Vintage, London

[64] Frazer, J 1993 (1922) The golden bough: A study in magic and religion, Ware: Wordsworth Reference

[65] Lang, A 1900 The Making of Religion, 2nd Edition, Project Gutenburg

[66] p30-38. Lowie, R 1937 The History of Ethnological Theory, Farrar & Rinehart Inc, New York

[67] Jaynes, J 1990 The Origin of Consciousness in the breakdown of the bicameral mind, Penguin, London

[68] Note that the bicameral mind hypothesis is not a widely accepted viewpoint. However, the examples on hallucinogenic nature of the mind are the key consideration for the current topic.

[69] We don’t have any prehistoric evidence to this.  But a crude deduction from the modern times makes the assumption of mental illness of the adolescents somewhat realistic.

[70] Arachige, D 2011 Witches, Shamans and the Girls at Puberty,

[71]p307-314. Bar-Yosef Mayer, Daniella E., Vandermeersch, Bernard & Bar-Yosef, Ofer 2009 Shells and ochre in Middle Paleolithic Skhul and Qafzeh, Israel: indications for modern behavior. Journal of Human Evolution, (56)

See also Henshilwood, C.S., d’Errico, F., Vanhaeren, M., van Niekerk, K. and Jacobs, Z 2004 Middle stone age shell beads from South Africa, Science 304: 404. Also note the modern discoveries about the use of symbolically meaningful objects by the Neanderthals.

[72] p. 165-91. Humphrey, N 1998 Cave Art, Autism, and the Evolution of the Human Mind, Cambridge Archaeological Journal 8:2

[73] A Chinook Indian belief. p599 of Frazer 1993.


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Punctuated Equilibrium, Gradualism and Hominid Cranial Capacity Data

Arachige D (2015) An Analysis of Hominin Cranial Capacity Data Using Simulations. Anthropol 3: 157. doi: 10.4172/2332-0915.1000157

Arachige, Darshi, Simulation-Based Analysis of Hominin Cranial Capacity Data (July 20, 2014). Available at SSRN: or

What did the reviews say?

I am really in debt to all the people who spent their time to read the above paper and comment on it. Thank you very much. Many comments were negative. However, I don’t see a strong argument against what my analysis pointed at: a possibility that the cranial capacity data pointing at punctuated equilibrium rather than gradualism. What I set out to do was to investigate the claim by Henneberg et al about the gradualism.  What I find is that the gradualism is not supported by their data. My effort was totally directed at being unbiased. At the end I believe there is no evidence in cranial capacity data to send Gould and Co to oblivion. Readers can also see whether the gradualist arguments hold any water. I believe that the readers wouldn’t let a argument to stand in the way of observed data.

I only intend to respond to a few reviews I received on this paper as they are the strongest arguments against my conclusions. In general, I am amused by the tendency of the scientific community to discredit the above paper on precariously weak logic. If the paper were difficult to follow and hence, the misunderstandings arise, I have to totally accept the blame. However,I sometimes wonder whether science at times is about people’s entrenched beliefs rather than the factual evidence.  When the undeniable arguments presented on a topic, human nature sometimes tend to rationalise the reasons for ignoring them due to the preconceived ideas about the person presenting them and the accepted opinions about the topic itself. I wonder this had something to do with the opinions expressed below as they are weak arguments against another set of data driven arguments. This opinion does not diminish in any sense the gratitude the author has for the people who made these comments.  I only can say a big “Thank you’ to show my sincere gratitude. The unedited comments from the reviewers appear below in bold letters.

I don’t find this paper sufficiently convincing to have me believe it makes an important advance in our understanding of brain size evolution. The author does a novel analysis of the fossil cranial capacity data, and concludes that there is evidence for two periods of change, with the changeover at ~1 MYA.I believe there are enough questions about the author’s statistical analysis that this conclusion is not any more or less convincing than previous studies coming to the same conclusion.

-This is a claim one would not consider sufficiently convincing to dismiss the paper. The review acknowledges the fact that the author used a novel analysis. Then the statistical analysis is dismissed as not convincing. Let us look at the objections to the analysis.

It is hard to follow all the statistical steps the author makes, to be sure they aren’t creating an effect where there isn’t actually one.As one example:

What would happen if you created simulated data that was based solely on the gradual curve that Henneberg et al. give as their best fit for hominin cranial capacities over time, and then did the K-means clustering on that? Would one get the same result (where assuming there are 2 groups gives the biggest drop in within-group SS)? In other words, is k-means making a 2 group solution because of its mathematics, and not necessarily because there actually where 2 groups?

-It is very strange for someone who is wondering whether the author’s conclusions are based on mathematical artefacts, to ask the authour to simulate data based on the Henneberg’s gradual curve and test for groupings. If authour were to simulate gradual change using Henneberg’s model, is the author looking at the real data or the artificial data? Would the conclusions then be based on the reality or mathematical artefacts? To simulate the data one has to make assumptions about the simulations so that the simulations are ‘grounded’ on reality. In the present analysis the author made assumptions about the distributions of the measurements on the cranial capacity of an individual skull. This is more grounded in reality than creating a simulated data sequence across all skull specimens. Should someone do further grouping on artificial data or the observed data? Also note that the paper uses unsupervised learning to identify the two groups while looking at the stability of such groups under simulations.

Secondly, isn’t it the case that any time you split data like this into two parts, and fit curves to these independently, you are going to get a better fit, no matter what? This is because you are able to capitalize on the unique variance characteristics of each segment. Given this, showing that the estimates are better for the two parts is not a good demonstration that there really are two evolutionary trajectories.The author could have tested this by arbitrarily splitting the data at random points (not using his preferred k-means clustering method), and see if the lines estimated for the two sections are also different. If they are (as I suspect they will be), then showing the differences between the k-means clustering derived sections is not particularly convincing (it would be an artefact of ANY split of the data).

-The above is a claim totally against statistical reality. Why do people test single regression line against multiple lines etc for the same data if they always get statistically significant good fit when the data were split? I don’t claim myself to be a brilliant statistician. However,  if there is no statistical evidence, a statistician will not accept that the multiple lines are better than a single line. This author did a statistical test to validate this. I am a pragmatist and like to do my statistics on the observed data.  This inclination prevents me from opting for tangential excursions into artificial sophistication.Why should someone split the data randomly and test whether splits are different?  Note that the author used a kind of a scree diagram which is equivalent to splitting the data from 2 groups to 15 groups. The K- means algorithm is used as an unsupervised learning technique in many areas in statistics including data mining. If this shows the evidence of some group structure, which has some back-up evidence, statisticians don’t go hunting for other groups unless the person is looking for groups with a hidden agenda. Even if this is the case, it is very difficult to justify a series of artificial splits. Any practicing data miner will confirm this. It is strange to suggest artificial splits on one hand and warn about artificial splits on another circumstance.
Thirdly, the actual split is at 1 MYA, not .5 MYA, yet the author focuses on the later.Yes, at that point, using his (possibly artifactual) second curve, the rate of change is greater than earlier. But it is by definition (in his model) part of one ‘process’ defined by that second curve which starts at 1 MYA.So how does this fit with supposed hominin species?And what about the problematic nature of hominin species, which are based on anatomical considerations that are under fairly constant reassessment? This reassessment means that our ability to place a particular fossil in a particular taxon (or even to define the taxa sampled in the first place) is more of a best-guess based on the limited data at any given point in time. I worry that the author is placing too much confidence in this placement of taxa in particular categories.If you look at plots of the actual data points (which the author does not include), it is very hard to believe one can prove that a two-curve model is truly better, particularly if you ignore the tentative species assignments that the specimens have been placed in. Henneberg’s graph of the actual data, as I remember, makes this pretty clear.

-The actual split is one million year according to the data unless the people who collected the data didn’t measure the skulls to make sure that was the case. The author emphasised the last half million years as that part showed a rapid increase. Any model is an artificial fit to the data and agrees with the general trend with ‘errors’ around it. If the authour fits a different model the things may look different. However, this is a model fitted by eminent anthropologist/s and discussed by many people and even accepted by the textbook authours. If the model is good enough to prove that the data follow the Darwinian gradualism why is it not good enough when it can also be used to show that the cranial capacity data does not necessarily follow the gradualism? Even after doing away with the tit-for-tat part of the above point, we are left with an intuitive analysis of same data not supporting the original claim of gradualism..

So I don’t find this paper sufficiently convincing to make it an important advance in our understanding of brain size evolution. People have indeed made the claim that punctuation can be inferred from the fossil cranial capacity data, and others have made the opposite (or have called into question our ability to know given the current data set). This paper applies a new set of analyses that claims to support some sort of change in brain size evolution at ~1 MYA. However, I don’t believe the analysis is strong enough to support that claim.

– The argument I posited in my paper was that the original authours didn’t have strong evidence to reject the punctuated equilibrium. I guess there should be something more than a personal belief to reject the claim made in the paper about non-gradual increase of cranial capacity.

This manuscript attempts to apply simulation methods to the problem of analyzing the evolutionary history of hominin cranial capacity.  The methods used do not strike me as particularly appropriate to the data.  For example, the use of k-means on what are essentially time series data is extremely unusual.  I have not searched the literature for whether there is a previous application, but I highly doubt that one could find any kind of cluster analysis where one of the variables is time. The notation, or at least the explanation of it, used in the manuscript is also poor.  For example, the equation for Hamming’s distance and its explanation does not seem correct.  It can’t be that we are looking for cases that are in a particular cluster five _and only_ five times or 995 and _and only_ 995 times, correct? But this is a really moot, because as I said, cluster analysis for time series data does not make much sense.

– This is another claim, which sounds weak. A technique not being used on time series doesn’t mean that the use of it in this instance is not logical. The cranial capacity data does not represent a true time series. If it were, time series wizards world over would have developed with hundreds of models to predict future cranial capacity.  The techniques in the paper were used not on the raw data as every statistician knows the clustering is usually done on a distance measure and in this case, Euclidean distance. As the time gaps and the cranial measurements do not follow a linear trend, until a trend was imposed using a model, the interrelationships between individual specimens and their time of existence can be looked at using the distances on two dimensions. This may not be ideal, as there would be some influence of time trend. But it is not easy to see the reason for the two groups solution. With regard to the Hamming Distance, I only ask the reader to be the judge. What I do at the end is adding up string of 1 and 0 to get the distance. And I was not looking at cluster five or 995 only. What I did was to find 25% and 975% cluster solutions out of the total simulated and if they are the same then the solution is more stable.

The description on page 6 of the simulation is a bit hard to follow. “R” has both rlnorm() which simulates “raw scale” random deviates given a log mean and log standard deviation and rnorm() which could be used to simulate log scale deviates given a log mean and log standard deviation. Simplest would be to convert cranial capacities to log scale “up front” and then find the necessary statistics (specimen means and sd where available) in the log scale.  And simulate in the log scale using rnorm().  Is that what was done?

-I don’t disagree with the above review. This was in fact what was done in the following manner to give one example.

summarydat4<-ddply(summarydat3, .(id,time) , transform, value=(rlnorm(1,mean,sd)))

Any one interested in duplicating what the author has done are more than welcome to drop in a note requesting the underlying data.


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Language Instinct, Elephant’s Trunk and Spandrels

‘The Language Instinct’ by Prof. Steven Pinker is a very thought-provoking read, which discusses the language as a gene-modulated evolutionary process tied to natural selection. Professor Pinker’s erudition and the astounding grasp of niceties of English language brightly shine through the book. It was a great piece of writing through and through which can adore any array of dazzling books on a bookshelf.  Irrespective of whether this writer is up to the task of criticizing an intellectual of Prof. Pinker’s caliber, I would like to pick on one or two points that troubled me about the book. If the reader were an arrogant Darwinist, taking all of it on faith, there would be little or no unanswered questions about the material discussed in the book. However, for a doubting Thomas like the writer of this article, the tone of the book is an unsettling eulogy of a one-sided world-view, which seems to scorn even the slightest hint of dissent on the orthodoxy of modern synthesis of evolution.

Professor Pinker’s key arguments about the unique features in animal kingdom arising from the slow natural selection process can be found in a chapter on the essence of Darwinian ideas (Chapter 11 The Big Bang). Unfortunately, the current writer was not convinced about the relevance of those arguments and counter-arguments about the process that gave rise to Language Instinct through the natural selection.  Furthermore, the logical foundation of these arguments seems to be more relevant to a philosophical discussion rather than to a persuasive scientific reasoning. Despite our physiological summersault, which could have well been fatal, of sending food and drinks over the opening to the trachea, to the food pipe, the language skills have evolved. The main point is about the process, which like the Elephants’ trunk, unique in the animal kingdom, produced physiological infrastructure required for our ability to talk.

Prof. Pinker acknowledges that the difference of Language from other animals’ communication systems is as obvious “as the elephant’s trunk is different from other animals’ nostrils (p334: Pinker 1994).” He further says that uniquely human language instinct is no more of a paradox than a trunk of the modern elephant (p342: Pinker 1994). Thus, we are apparently supposed to acknowledge the possibility of a process analogous to, in its uniqueness, what gave rise to the trunk, offering us our unique ability to communicate. This view is inadvertently trying to use an argument of “analogy”, namely, the uniqueness about language skills of humans and the evolutionary path of the elephant’s trunk.  This analogy about these functionally different characteristics does not seem to prove that the language is not a spandrel. On the other hand, each and every species is unique and the uniqueness itself can only support Prof. Pinker’s point to the extent that completely unique evolutionary adaptations can arise. If the elephant could talk like a parrot with the help of  its trunk, it would have been a far more reasonable comparison.

Taking a shot at the work of Professors Gould and Lewontins on spandrels, perhaps latently provoked by their dismissal of “just-so-stories” coming from evolutionary psychology, or dismissing Professor Chomsky ‘s more measured views may not hold any substance as a scientific device.  I do not think for a moment that Professor Chomsky, a true genius insightful enough to propose the widely accepted theory of inborn universal grammar, didn’t master the Darwinian views. He only tiptoed on a topic, which many Dogmatic Darwinists are inclined to believe as the absolute truth. Even if the natural selection produced the elephant’s trunk, there’s no guarantee that the same is true for human language.

Prof. Pinker agrees that “Gould and Lewontin’s essays have been influential in the cognitive sciences, and Chomsky’s skepticism that natural selection can explain human language is in the spirit of their critique (p359: Pinker 1994).”

This is obviously the case when Chomsky writes, as quoted in Prof. Pinker’s book, “These skills (for example, learning a grammar) may well have arisen as a concomitant of structural properties of the brain that developed for other reasons (p362: Pinker 1994).” This clearly is a mention of a spandrel, which may be a more natural treatment of the origin of language. This writer couldn’t find an argument in the book to defend a direct adaptation. Prof. Pinker himself says that only suggestive evidence for a grammar gene is available and its locus, given such a gene exists, is completely unknown (p.325: Pinker 1994). Lai, C.S. et al. (2001), identified a gene FOXP2 as the gene responsible for the language impairment of London Family known as KE family. To their credit, this may be the gene Prof. Pinker’s collaborator, Prof. Myrna Gopnik and Prof. Pinker postulated. However, more likely scenario would be what Jon Cohen says in his article ‘The Genetics of Language’: problems such as language impairment “are caused by subtle aberrations in genes and networks of genes working in concert[1]. But it is still not known whether FOXP2 affects the neurons processing the language or the ones controlling the speech muscles[2]. Until the discovery of such a gene or a network of genes and their direct involvement through natural selection it is more logical to agree with Prof. Chomsky, is it not? The Language faculty may well be a by-product of the encephalization process which accompanied the making of human. If analogy is a good argument, why didn’t natural selection work for talking birds, who can pick our speech and vocalize it so well, to develop language faculty, which is simply “an adaptation for the communication of knowledge and intentions (Pinker and Jackendoff 2005)”?  If they mastered vocalization like our language how well it would serve their survival and dispersion. Their communal behaviours may not be as complex as ours but a complex language beyond a mating or territorial call will still help. We know this from Vervet monkeys who possess a repertoire of alarm calls.

The point I am trying to make here is that the origin of language should not be pigeonholed to a Neo-Darwinian mould without enough supportive evidence. Such procrustean view may lead to wrong conclusions and a hold-up of further development of visionary ideas. This brings me to a story, about the mammoths, that I recently read. It tells the story brought in by the Russian explorers who met the Dolgan, a tribe of reindeer herders, centuries ago. They warned the explorers about the giant moles that avoided sunlight and fresh air. As soon as they broke through the ice cover they died instantly (p 53: Firestone et al). This is an example of the use of the rule of thumb logic by these tribesmen reminding of conceptual similarities to homology; the subterranean life of furry mole and the ice covered bodies of wooly mammoths. The limited knowledge the tribesmen had about their surrounding was extended to a novel situation based on vague similarities between mammoths and known creatures. In the shadow of the status of our current knowledge, such may be the connection between Language Instinct and the effect of the known genetic basis. At this point in time, the experts don’t know any better. But, there is no doubt that Prof. Pinker’s book is an insightful book to read.


Pinker, Steven 1994 The Language Instinct, Penguin Books

Firestone, R., A. West, and S. Warwick-Smith 2006 The cycle of cosmic catastrophes, Bear and Company, Rochester

Lai, C.S. et al. 2001 A forkhead-domain gene is mutated in a severe speech and language disorder. Nature 413: 519–523

Pinker, Steven and Ray Jackendoff. 2005 The Faculty of Language: What’s Special About It? Cognition 95: 201–236



[1] Cohen, Jon (2007) The Genetics of Language, MIT Technology Review

[2] Prof. Richard Huganir as quoted by Pennisi, Elizabeth (2013) ‘Language Gene’ has a partner,

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