Logical fallacies

Collective work, debates, philosophical thinking and the progress of social sciences and humanities, are commonly disturbed by logical errors called “sophisms” or “logical fallacies”.

Here is a non-exhaustive list:

Attack the person rather than the ideas.

Distort the other’s words to attack him or her.

Confound correlation and causation: it is not because two phenomena occur at the same time that one is the cause of the other.

Present two possible alternatives, “all black” or “all white” when there may be others, for example consider that one is either “pro-migrant” or racist.

Believe that an idea is right because a majority of people share it.

Believe that a good idea is an idea “between two extremes” or “average”, in other words, looking for a compromise rather than the truth.
For example: in Morocco, there are women who go hair free, others wear a veil that covers the hair, others cover their faces. Thus, the “middle ground” for most Moroccans is the veil that covers the hair. Yet in other cultures, the border of decency is different.

Invoke “God”, “nature”, “genetic determination” or any ideology, to prevent criticism. For example: to say that women are not good at mathematics, because it’s in their genes.

Believe that an idea is true because it is emitted by experts. Nobody is infallible, so being an expert does not free from having to argue and prove an idea.

Believe that an idea is true because one can not prove its opposite. For example, God exists because we can not prove that He does not exist.

Make a single example a generality.

Assume that the preferred alternative is true when an idea is ambiguous.

Appeal to emotions, for example using sentimental blackmail or raising the threat of a catastrophe.

Respond to criticism by another critic, instead of disassembling the criticism itself.

Believe that an idea is wrong because it uses fallacious arguments. Although the logical fallacies presented here can lead to errors, this does not mean that all the ideas expressed in this way are false. This means that they must be demonstrated with more methodological rigor.

To extend this list to all the phenomena that can alter the efficiency of a debate, we can mention:

Speaking louder than the interlocutor, and thus give the audience the feeling of being “the strongest”. This does not mean that the idea is more relevant.

Interruptions: the interlocutor thinks he/she knows the end of the speech of the other or does not worry about his/her ideas, and therefore cuts it. In addition to showing aggression, arrogance and disrupting the focus of the speaker, an interruption may make the meaning of the speech quite different from what it should have.
I was very embarrassed one day when, in a feminist society, I wanted to say, “Women are hurt by ideological pressures to prevent them from aborting, but what about men? Don’t they have a responsibility in those dramas?”, and that one of the feminists cut me off after “but what about the men?”, to say that indeed, it was not fair for her son, whose girlfriends could have an abortion against his will. The other women were so eager to express their revolt that I did not have the opportunity to complete my remark.

These phenomena also handicap the functioning of a democracy, since the latter is based on debates of ideas. Parliamentary debates and other mediated exchanges should ideally be framed to avoid them, for example, by training participants, correct them during debates, cutting the sound of others’ microphones when someone speaks, etc.



Contemporary life has progressively moved us away from a sensory reality by replacing it by symbolic realities that make sense to the human community. In doing so, it locks us into the human comedy.

Symbols realize an association between elements of reality and a simplified way of representing them, which is understood by the human community.
It can be language, in oral and written form, mathematics, programming algorithms, and so on.

Symbols allow us to communicate with others, and other human beings are sources of attachment and survival. For this reason, symbols become so important that they come to supplant and atrophy sensory reality.

In other words, they are also sources of alienation. The child progressively moves away from his animal intelligence, his total sensory impregnation, for a symbolic reality that simplifies it in a sketch understood by the human species.

The importance of the verb in the building of hopes and fears of humanity that are religions, is an emblem of its power, particularly in religions based on writing that are the Abrahamic religions.

The Bible and the Torah teach us that everything begins with a divine word:

God says, “Let there be light!” And there was light.
The Bible, Old Testament, Genesis, 1:3

Saint John is more explicit. He assures :

In the beginning was the Word, and the Word was in God, and the Word was God.
The Bible, New Testament, St Jean’s Gospel, 1:1

The Qur’an tells us:

This is the Book about which there is no doubt, it is a guide for the those who fear God.
Qur’an, Al Baqarah (The cow) 2:2

In other words, the truth is contained in a book, in words.

However, language is a recent invention, it appeared with our species, that is to say, a few hundred thousand years ago. It is just a drop in the ocean of cosmic time. A drop in the history of nature itself, which is several hundred of millions years old, according to scientists.

The Tao-Te-Ching is more cautious. The word Tao means “the way”. The Tao Te Ching can be translated as “The Book of the Way and Virtue” or “The Book of the Righteous Way”.
The oldest fragments of this book have been dated to the 3rd century BCE, but some think that the philosophy it describes is much older.

The Tao Te Ching tells us:

The way that can be said is not the eternal way.
Tao Te Ching, chap. 1

What is the verb?

I propose the following definition: The verb is a set of symbols, each representing a redundant aspect of reality. The symbol is a graphic element or sound. Humanity uses these symbols to communicate with others and make predictions in order to take control of nature.

But the perfection of our symbols does not exist in reality. A perfect round does not exist, a cat never looks like another perfectly, one and one are two in reality if the two units are perfectly equal, which is never true. Reality is not in concepts. Reality is not in verb. Reality is impure, chaotic.

We can remember or delve into the past as archaeologists, or project ourselves into the future, we only get ideas. Reality is sensory. Even though our senses are limited, they offer a more reliable reality than our concepts, which are always too simple, too perfect.

Some people realize what they lose in the process of replacing sensory reality with a symbolic or virtual one, and they need a long practice of art, meditation, or music, to regain some of the bliss of the baby, wholly surrendered to her/his senses, as confident in the belly of nature as in the belly of her/his mother.

Science, which dissects the elements of nature by describing them with symbols, cuts us off from the marvels of reality, which, could be presented at the same time.

How many know that proteins, workers of our cells, which structure is schematized, like any molecule, by means of colored balls for the atoms, retained by sticks, can join to form a structure that folds several times on itself to reach a complex form adapted to its function, sometimes even micro-motors capable of moving a flagellum? And when these proteins are concentrated in pure state, they aggregate to form beautiful crystals reflecting light on a multitude of colors?

Protein crystals
Protein crystals.
Source: Oregon students’ blog

To represent a cell, we represent a potato for the membrane, with a round for the nucleus, corrugated tubes for the mitochondria, sausages for the Golgi apparatus, sticks for the proteins, etc …

But when we observe unicellular organisms under a microscope, we are amazed by the beauty and complexity of these delicate buildings.

We trust science only, to the point of seeing ancient rituals as archaic superstitions. For example, in the French countryside, people used to make bouquets with ears of corn during the harvest festival, and hang them in the houses to bring prosperity. These rituals reveal as much as maintain an attachment to nature.

Makilam, author of “The Magical Life of Berber Women in Kabylia” describes the perception of cycles of nature for the Kabyle people of her grandmother’s time:

Today, the “modern man” can distance himself from the macrocosm and consider it from the outside. He can indeed, thanks to the logic of its graphic and rational thought, be abstracted and project himself outside the solar system. […] But the peoples of nature did not reason, they lived from themselves and referred to what they saw and perceived in all their senses, unlike the modern man, which has adopted the laws of rational science. In his reasoning, he dissociates from himself as a corporeal entity when he perceives reality only through thought. He thus sees only one aspect of his human nature since he projects himself mentally outside of the place and the precise moment in which he finds himself. As a result, the written calendar no longer reproduces sidereal time because it no longer reads in the sky. This new form of linear thinking involves the separation of the human person from the rest of the earthly nature from which it no longer depends for the organization of its material activities. On the level of consciousness, today’s human being perceives himself as separated from the life of the Great Nature and constantly lives the duality of his nature in relation to the cyclical overall life of his environment.

The child who has not yet learnt to speak is in a state of perception of reality not hidden behind concepts, which was ours at the dawn of humanity.
When we are small, we see quantities instead of counting them. We observe reality instead of conceiving it. A wooden table is not a wooden table for a baby. It is a flat mountain with above a universe of stripes and ellipses on different shades of brown.

A long time ago, while humanity was leaving the animal kingdom by acquiring an awareness of its inexorable mortality, when we used to paint animal life on the walls of caves and carved maternal bodies, before arts, technics, explorations, became reserved to a male elite, tens of thousands of years ago, we lived more on an immediate, sensory reality. We had no choice because we were expecting dangers and facing adversity. We did not learn so many concepts, of which prejudices are part. We were more instinctive. Our thoughts were more tinged with sensations. Only nature, much more beautiful and varied than today, offered itself to our senses.

Little by little, the verb and other mental projections have replaced the sensory reality, for the evolving humanity as for the child who learns to speak. Because the verb allows us to communicate with our fellow beings, and nothing is more important than them. Many of our nonverbal mental projections are also related to others. They are our guarantee of survival. But as these symbols cut us off from reality, other human beings becomes even more important because they becomes our main source of satisfaction.

Thus, reality gradually gave way to a predictable play, with oneself as the main actor, which scenes and roles are always the same, and the audience is only oneself. We have moved away from our animal condition by losing much of our sensory attachment. We have moved away from the flow of life that gave birth to us, the original womb, nature.
In the redundancy of our play, our spirit dies.

We are stuck like hens in a cage, in an office, an apartment, a car or other means of transport, tunnels of gray concrete and macadam. The gray of our walls is accompanied by that of our sounds, those of cars and city works … the noises of ourselves, murmured on TV, around us, and in an infernal cycle in our mind. The smells and flavors have become just as gray, sterilized by pesticides, fertilizers, hormones and other poisons, suffering of people, animals and nature.

In prehistory, although we sometimes had to suffer physically, our senses were on alert and we struggled to survive. Now, stuck in our cages, we peck in the cages next door.

When we lived in caves, we had to rely on each other. But now we are locked in the sinister comedy of disguised people, and it is this disguise that determines the comfort provided by others.

We are insane. We have lost the meaning of our life. We have lost our instincts.

The influence of prejudices

In all scientific fields, prejudices can affect the perception of reality.

When I was in high school, I had a particularly sexist math teacher. He told us that women were rather good at litterature, and men at mathematics. He believed it so much, that one day he made a miscalculation by counting my points on a copy: he had counted 8 instead of 14 / 20. I counted the points in front of him, and he had to bow to the evidence, which made him very angry.

Sexist prejudices also influence the way in which objects of study are perceived when they relate to living beings. This is particularly notable in the study of the animal world, history and archeology.

Animal observations

The animal social organization is often described by projection of our ways of life. Finally, animal documentaries tell more about our prejudices and our narcissistic aspirations, than about the animals themselves . Added to this bias is the need to make the image commercially attractive.

The myth of the dominant male

In groups of animals where agressive competition between males exists, it is observed that there are, therefore, groups with a larger number of females than males. Sometimes there is only one male, or only one of the males can mate with the females. The commentators deduce that this is the “dominant male” and his “harem”. But, by this expression: “dominant male”, one could understand that he also dominates the females.
This may be the case with some of our closest primate cousins, but things seem less obvious about other species such as, for example, deer, cattle, elephants, wolves or cats…
Does the male restrict the space of the females, does he control their actions, as does a man who has a harem of wives? Is he violent toward the females as he is toward other males? Can we talk about “harem” if females sometimes mate with other males, as we often see in these groups?

A lion with his harem, or lionesses with their reproducer?
A lion with his harem, or lionesses with their reproducer? Photo by Brian Scott

By observing, for example, a pack of lionesses with a lion, one could also change perspective and say that it is a group of lionesses who share a male, who may be pampered because he is unique, but he does not dominate them.

Things can be different, however, when animals are in a stressful situation, such as living in a cage. Promiscuity, lack of sensory stimulation, inability to move, can induce aggressive behaviors, in animals as in humans, males or females. In this case, the strongest have an advantage, which is the case of males in species where they are bigger.

The myth of the protective male

It is customary to say that the male protects the herd. But, on the contrary, he is often a threat to the little ones. The female must fight against him or soften him by sex, especially among mammals practicing an agressive competition between males.

There are exceptions however: when the male takes a nurturing role (for example, the albatross). Then he becomes a second “mother” and protects the babies and the territory with her.

The need to sell

In order to offer sensational images, documentaries show mostly scenes of predation and fighting between males. But these activities do not constitute most of animal time. They, male and female, also spend time exploring, resting, cleaning, chewing, playing, helping each other or hugging. Videos shared on social networks offer a very different vision of the animal world:
Animal tenderness shared by Animals Australia.
Animal solidarity, compilation of several amateur videos.
Attachment between humans and animals in an hunter-gatherers tribe (Awa Amazonian tribe), by Survival International.

Finally, the most honest animal documentaries are those that are not accompanied by any comments, any music other than that of nature itself, and which offers scenes faithful to the everyday life of an animal, in order to give, to those who have the joy of discovering these recordings, the happiness of observing and hearing nature as it is offered to us.

History and archeology

Merlin Stone, in her work “When God Was Woman” (1976), analyzed many writings on the pagan faith that preceded Abrahamic religions, especially ones that turned to a feminine image of the divine. She writes :
In most archeological texts the female religion is referred to as a “fertility cult”, perhaps revealing the attitude toward sexuality held by the various contemporary religions that may have influenced the writers. But archeological and mythocological evidence of the veneration of the female deity as creator and lawmaker of the universe, prophetess, provider of human destiny, inventor, healer, hunter and variant leader in battle suggests that the title “fertility cult” may be a gross oversimplification of a complex theological structure.

Riane Eisler, author of “The chalice and the blade”, also attempts an interpretation of the abundant number of female figurines found in the remains of the Neolithic and Antiquity, particularly in Europe and the Middle East. She also questions the choice of the term “fertility cult” used by archaeologists. She notes that this term is probably as reductive as qualifying Christian crucifixes as a “death cult”, if these prove to be discovered in the future by a humanity that has forgotten the Christian religion.

One reason this point is obscured is that scholars have in the past routinely referred to the worship of the Goddess, not as a religion, but as a “fertility cult,” and to the Goddess as an “earth mother.” But though the fecundity of women and of the earth was, and still is, a requisite for species survival, this characterization is far too simplistic. It would be comparable, for example, to characterizing Christianity as just a death cult because the central image in its art is the Crucifixion.
Riane Eisler, “The chalice and the blade”, 1987

Merlin Stone gives other blatant examples of observations altered by sexual gender biases:

J. Maringer, professor of prehistoric archeology, rejected the idea that reindeer skulls were the hunting trophies of Paleolithic tribes. The reason? They were found in the grave of a woman. He writes “Here the skeleton was that of a woman, a circumstance that would seem to rule out the possibility that reindeer skulls and antlers were hunting trophies”.
In 1961, a serie of mistakes were described by professor Walter Emery, who took part in the excavations of some of the earliest egyptian tombs. He tells us that “The chronological position and status of Meryet-Nit is uncertain, but there is reason to suppose that she might be the successor of Zer and the third sovereign of the First Dynasty”. Writing of the excavation of this tomb by Sir Flinders Petrie in 1900 he says “At that time it was believed that Meryet-Nit was a king, but later research has shown the name to be that of a woman and, to judge by the richness of the burial, a queen”. He goes on to say “In 1896, de Morgan, then Director of the Service of Antiquities, discovered in Nagadeh a gigantic tomb which, from the objects found in it, was identified as the burial of Hor-Aha, first king of the First Dynasty. However, later research has shown that it is more probable that it was the sepulchre of Nit-Hotep, Hor-Aha’s mother”. And again he tells us that “On the name of Narmer a seated figure in a canopied palanquin was once thought to be that of a man, but a comparison of similar figures on a wooden label from Sakkara shows that this is improbable and that it most certainly represents a woman”. Yet, despite his own accounts of this serie of assumptions that the richest burials and royal palanquins of the past were for men, rather than women, in describing the tomb of King Narmer he then states “This monument is almost insignificant in comparison wit the tomb of Nit-Hotep at Nagadeh, and we can only conclude that this was the king’s southern tomb and that his real burial place still await discovery…”. Thought some pharaohs did build two tombs, one might expect a “possibly” or “probably” rather than such an absolute conclusion and the implied dismissal of the possibility that, in that period of earliest dynastic Egypt, a queen’s tomb just might have been larger and more richly decorated than a king’s.

Archeological news surprise by the number of errors of this type, revealed by modern methods of analysis.

The Palace of Knossos in Crete is another example. The remains reveal many frescoes which, in their reconstruction, show human beings, animals, plants. A large number of these frescoes show women, beautifully dressed and with bare breasts. Female figurines holding snakes were also found.

Minoan goddesses figurines
Minoan goddesses figurines from Knossos – Archaeological Museum of Crete in Heraklion.
Source: Wikimedia Commons

The first to report an analysis of this site is archaeologist Arthur John Evans. He concludes that it is the palace of a king and his harem. According to Arte’s documentary “Archaeological Surveys – Crete, the myth of the labyrinth” by Peter Eeckhout (in french), more recent analyzes have shown that the engraving of the man that Evans claims to be that of a king, was built from several pieces found at different places of the site. The researchers also found, in a room at the elevated seat, the engraving of a woman sitting on an identical seat. Today, most researchers agree that the palace was initially a temple of ​​priestesses, and that a woman sat on the throne, but the site must have known several means of governance, because the most recent constructions seem to reveal hierarchical relationships, which is not the case of the most ancien ones.

Often, when excavations are carried out on tombs in which remains of the skeleton do not allow to identify the sex, the archaeologists assume that the tombs with weapons are tombs of men whereas the tombs with jewels are those of women. When these results are popularized, it is deduced that since the dawn of humanity, men carry weapons and women jewelry. This is a fallacious logic, one of the many examples of the way in which prejudices are self-perpetuating.

In fact, when more rigorous analysis of the bones are done, we can see that there are many women buried with weapons, and men with jewels. Shane MacLeod, of Western Australia University, has shown that women were buried with weapons in Viking tombs in England. The same observation was made by researchers at the Uppsala and Stockholm Universities on excavations of Birka in Sweden, this time performing genetic analyzes on bones. Jeannine Davis-Kimball also notes that women are buried with weapons in Kurgan graves in the Porkovka site in Kazakhstan.

Woman buried with weapons and horses, excavations of Birka, in Sweden
Woman buried with weapons and horses, excavations of Birka, in Sweden.
Source: Wikimedia commons

An identical fallacy exists in the determination of the sex of the Australopithecus. The smallest skeletons are attributed to women (this is the case of the famous Lucy). Bioanthropologist Robert Martin, in a report by Arte “Why are women smaller than men?” by Véronique Kleiner (in french), says that it is an arbitrary position. Larger skeletons have been attributed to male Australopithecus, but he says it could also be another species. All that is certain, he says, is that we have large specimens and small specimens.
This arbitrary decision on skeleton’s sex may lead to the idea that sexual dimorphism was important at the beginning of humanity, and this idea then serves as a reference for future examinations and theories.

Merlin Stone notes that many ancient writings are vague enough to give great differences of interpretation between translators, and in this case the influence of their prejudices is even stronger.
This is something everyone can do, observing the diversity of translations that have been proposed for very ancient texts, such as hieroglyphic, cuneiform or old Chinese writings.
Sometimes, in these translations, information is ignored because it is not considered useful, but, as a result, part of the state of mind of the culture that gave birth to these texts is lost.

A significant example is the diversity of translation that exist for the Tao Te Ching. The word “Tao” refers to the way, the balance, the conduct, the source, the primordial mother …
Some translators emphasize the maternal essence of the Tao while others exclude it totally. An interesting comparison is available on ttc. tasuki.org

However, could we think, are not the prejudices built, ultimately, on a reality?
When we look around, even with an effort of objectivity, is not the domination of men over women, and the law of the strongest in general, everywhere? Is it not legitimate to deduce that it has been so since the dawn of time?

In fact, there are many exceptions to patriarchy. Some societies have adopted a matrilocal and matrilineal type of parentage, that is to say that girls, or only one of them, remain in the parents’ home and inherit their property, while taking care of them in their old age. These are for example the Garo or Khassi of Meghalaya, the Mosuo from China, the Minangkabau from Indonesia, the Iroquois from America… Explorers tell us about several other societies that have worked according to this system, before almost all peoples became subject to religious or philosophical systems of patriarchy, such as Judaism, Christianity, Islam, Manu laws of Hinduism, Confucianism…

Indian Garo couple with there traditional dress
Garo Young Boy and Girl with there Garo Traditional Dress during a Wangala Festival at Asanaggre 14 KM from Tura. On saturday. Photo by Vishma Thapa.
Source: Wikimedia Commons

The way of living of a human society also depends on environmental conditions and contacts with other civilizations. When these elements of the environment change, so does the way of life.

It is probable that a long time ago, when humanity was less numerous and therefore less subject to conflicts, a large part of humanity at least respected the natural affiliation that binds the child to her/his mother more than to her/his father.
Perhaps that the development of attractive commercial centers, cities, has favored an agglomeration of populations which, if they are poorly protected, easily become the prey of the most violent and the most plundered of them, for whom a system of filiation which favors the strongest does not seem unnatural.
Anyways, to make an average of what one observes today a global generality, immutable, even ideal, leads certainly to errors.

History is also a tool of power, because we tend to learn from the past to improve the future. It is easy to manipulate the official version of History to make certain ideals acceptable.

Who controls the past controls the future.
Who controls the present controls the past.
George Orwell “1984” (published in 1949)

Obsolete foundations

School and university programs, museums, documentaries, ignore the abundance of discoveries based on modern tools, or an unusual point of view, that would crack the dinosaur that is the official stream.

Jean Piaget, a researcher in child psychology, describes learning in two ways: assimilation and accommodation. The first adapt the information of the environment to our structure of knowledge, the second adapts our structures of knowledge to the information of the environment.

In my profession, computer programming, requests often vary significantly throughout the project, to the point that, if we wanted to do well, we would have to recode the whole program, which makes developments particularly long. It’s like destroying a house and laying again and again the foundations for it, because customers decide what their home will look like as they see it grow. For reasons of time and budget, it is hardly possible to do so. Therefore, we proceed by “assimilation” of new features, without rethinking the whole, in other words without “accommodating” the existing. The new functionalities accumulate in a chaotic way, the anomalies are numerous and the reordering that it would be necessary to do, would take at least as many time than the one already passed.

This is also what happens in the progression of academic knowledge.
Challenging the foundations of academic knowledge involves bringing together experts who are authorities in their field, and agreeing with them, which is far from easy. They may have published works on obsolete bases, so their reputation is at stake, as well as the reputation and wealth of museums and libraries.

Yet, there are many things, that everyone can observe, that make official versions of science or history doubtful.

How to integrate, in our biological and chemical knowledge, the effectiveness of parallel medicines, such as Ayurveda (Indian medicine), meditation, yoga, compared to the chemical or surgical intrusive cures that doctors usually use?

How to have faith in the dating of Celtic and Roman civilizations, while the oldest copies of latin texts available in libraries and museums, and which serve as historical references, date from the ninth century – if we believe the estimates – or even from the Renaissance?
The earliest copies of Julius Caesar’s “Commentaries on the War of Gaul” (“Commentarii de Bello Gallico”), the main historical source for describing the Celtic peoples, are estimated in the 9th century AD. One of these copies is kept at the National Library of France (BNF), the other in Amsterdam. The oldest (partial) editions of Titus Livius’s “The History of Rome” (Ab Urbe Condita Libri), one of the main historical sources of the Roman Empire, are also estimated in the 9th century AD. One of these editions is also kept at the BNF.
The website tertullian.org has a remarkable list of the oldest known manuscripts for most classical Greek and Latin authors, and their estimated date.

Commentarii de Bello Gallico - Julius Caesar
One of the two oldest copies of Julius Caesar’s Commentary on the War of Gaul, estimated in the first half of the 9th century, preserved in the National Library of France (BNF). Source : BNF Archives

Other inconsistencies between archaeological data and official chronology are observed by researchers such as Anatoly Fomenko and Gleb Novosky.

The areas of academic knowledge or computer development are not the only ones that evolve this way. A major problem for democracies today is the exponential development of laws and jurisprudence, which is not always accompanied by a concern for clarity and coherence. The same goes for administrative procedures. When we know that “no one is supposed to ignore the law”, we can measure all the difficulties and costs that this represents for businesses as well as for ordinary citizens. This complexity is probably one of the reasons slowing down the adoption of democracy in some parts of the world.

Reality and test tubes

We are doomed to make misstake when we try to simplify human attitudes by numbers and categories. The human being and its environment are very complex and to think that we can totally identify and isolate a cause and an effect through an experience is an illusion. How can we put the infinite complexity of nature into a test tube?

Experimentation in humanities

Differential psychology attempt to study the differences between social groups based on experiences and inferential statistics. An experience consists in isolating an independent variable and a dependent variable, to observe the effect of the variation of the first on the second. Inferential statistics uses probability to state whether differences found on samples of subjects are “significant”, that is, if the difference is big enough to make sense, and how much we can generalize on the parent population, with a margin of error.
There are several things to be aware of about these experiences:

Correlation does not mean causality. If two factors are correlated, for example gender and performance, this does not mean that one explains the second. More relevant factors may be educational, such as toys that subjects received in childhood and that influenced cognitive development.

These results are not definitive. A person can improve her/his performance in one area through exercise or change attitudes by changing self-image. The brain is a very flexible organ.
For example, according to a study by Kass, A.J. Ahlers R.H. and M. Dugger, (1998), with learning, differences in spatial geometry scores disappear.

These results are not systematic, there are people who have an excellent performance in a task in which their socio-cultural group uses to perform badly, and the other way round may be true too. Results generally follow a Gaussian curve, which is a reversed bell, the majority of the scores grouping around the average. When the performances of two groups of subjects differ, it is according to two Gaussian curves which intersect. this means that even if there is a “significant” difference of average between two groups, there are always individuals in the lower average performance group who exceed individuals in the higher average performance group. Unfortunately the perception of the public is such that it believes that all people have a performance corresponding to the average of their socio-cultural group (see the diagrams below).

Chart of performances in spatial task
Example of chart of results on a task in which men are known to do better in average (such as spatial task)

Validity of experiences

When experiments are shared through scientific publications, it is easy to ignore certain results or to add fictitious ones. When budgets or ideals are at stake, there is no doubt that some experiments are more or less falsified. Sometimes their results are accepted by the scientific community without any attempt to replicate them.
Nature is full of diversity, so it is easy to find the data we want in relation to our ideology or financial interest, and to ignore other data.
For example, there are pharmaceutical industry experiences that deliberately ignore the side effects of drugs. See Ben Goldacre’s conference on TED.


“Scientific” observations on cognitive gender difference

Some researchers feed sexist arguments with hormonal comparisons, descriptions of differences in anatomy and chromosomes, and draw an arrow that they call for “cause” to all the social and psychological differences, as if the fact of having a vagina and estrogen predisposes to stay home and take care of children, to be emotionally unstable, and intellectually less creative and less technical than men.

No doubt there is a genetic influence in the human personality. The results of research on identical twins separated at birth show that they have, for example, the same preference for certain foods. But this does not mean that there is a part of genetics in everything, especially in something as culturally anchored as sexual gender differences and their impact on the development of intelligence. All genetic studies show that the characteristics of the parents are transmitted to children regardless of their gender, so an engineer father can transmit to his daughter his taste for mathematics, for example.

These scientific and sexist publications are all the more harmful as they are the opposite of the type of information that allows the individual to have faith in her or him, in order to persevere in skills development. Carole Dweck (already mentioned in the article Role models), shows that the idea that some individuals have innate and fixed predispositions lead people to flee the challenges and to give up easily in case of failure. On the contrary, the idea that all skills develop with practice, encourages one to persevere in efforts, to accept criticism and to embrace challenges.

The brain is indeed a flexible organ. Brain structures change when a person, for various reasons, acquire new skills or change attitude: other areas of the brain are stimulated, other neurotransmitters are produced. If there are researches that show average biological differences in the brain by using statistics over a large number of people, they reflect social differences, they don’t explain them.
Recent research shows that even genes expressions are modified with experience! This is the field of epigenetics.

Catherine Vidal, neurobiologist and research director of the Pasteur Institute of Paris, has published many articles on the question of brain differences between genders. She has also made a speech on Ted, available on youtube (you can turn on english subtitles):


Here is a summary of her main observations:

– Some researchers claim that women are less intelligent than men because their brain is on average smaller. But other studies show that brain size is not related to intelligence. Catherine Vidal mentions famous smart people who had a small brain.

– Others have done research on the relationship between sexual orientation and genetic and neurophysiological factors. Catherine Vidal shows that these studies are invalid and not confirmed by other similar studies.

– Other researchers claim that men and women use their brain differently. For example, one researcher wrote that men use the left brain more than women (he based this theory on an observation of about forty people), but this research was not confirmed by observations over a larger number of people. Another researcher shows that corpus callosum (which connects the two hemispheres of the brain) is larger in women, by observing twenty brains preserved in formalin, and it has inspired many ideas on the fact that women would be better at multitasking. This observation was not confirmed by analysis of a larger number of brains. Unfortunately, due to the popularity of these researches on various newspapers and documentaries, many people continue to believe them, even though they have been invalidated.
Recent studies show that individuals, regardless of gender, use different parts of the brain to solve the same task. Catherine Vidal writes “A major contribution of magnetic resonance imaging (MRI or MR) was to reveal how much brain function varies over different individuals. So it is, for example, when using mental representations to solve a problem, as mental arithmetic or chess. For the same performance, all have their own way to activate neurons and organize their reasoning”..

– Catherine Vidal also shows that most of the brain develops after birth. Thanks to magnetic resonance imaging, one can see the brain changing after learning, such as in musicians: “Thickening of the regions that are specialized in finger control, hearing and vision”, among taxi drivers: “areas of cortex that controls the sense of direction is more developed, and in relation to the number of years of experience of driving a taxi”, among jugglers: “thickening of the regions that are specialized in vision and coordination of movements of arms and hands”. The same phenomenon has been observed in people who develop more abstract knowledge (chemistry, physics, biology). These studies show the brain plasticity, and Catherine Vidal concludes: “to see differences between individuals or between sex does not mean that they are inscribed in the brain from birth, or that they will remain.”.
In this regard, it is interesting to note that these cerebral observations are also used by the team of Mindsetworks (inspired by Carole Dweck), to encourage children of both sexes, through an educational video, to persevere in efforts.

– Other studies show that women perform better on tests of verbal ability, and men in tests of spatial ability, in average. Catherine Vidal explains that these differences are not systematic : “the spread of values ​​is such that there are a large number of women who are better in tests where men succeed better in average and vice versa,”. They are not definitive, “after learning these differences disappear”. Moreover, these differences are small. They may even disappear, for example, when an exercise is presented as a drawing task instead of a geometry task (this confirms the “stereotype threat” effect discussed in “Roles models“).

– The relationship between hormones and behavior is also questioned. No studies confirm the relationship between testosterone and aggression in men, for example, and there is no hormonal imbalance in homosexual people. Catherine Vidal writes (and quotes Zweifel): “In normal physiological conditions, no scientific studies have shown a direct relationship between hormone levels and changes in our mood”. In humans, unlike animals, behaviors are based on more complex causes of social and cultural nature. Maybe some hormonal changes have an influence, but differently for each person, because abstract reasoning is stronger in human beings, and it is built through a diversity of experiences, specific to each individual.

The limits of measuring instruments

Science gives us the idea that one day, everything will be under control, since everything obeys regular rules. We just need to find the mathematical formulas which best mimic the observations, in order to make predictions.
In fact, it is true in an environment where everything is under control, and if we accepte the limits of what we can observe on our scale of space and time.

The laws of gravity don’t explain some movements of the stars, for example the fact that galaxies are moving away from each other faster and faster. To explain it, we invoke “dark matter”, unobservable directly, and exerting a gravity force. But in fact, we do not know.

Even in our conceptual and sensorial framework, it is difficult to reproduce an environment accurately, and therefore to make perfect predictions, because our measuring instruments are limited. And we know that very small differences in initial conditions, which are not always measurable, can produce very different results.

This was observed by a meteorologist named Lorenz in the sixties. He made weather forecasts based on complex mathematical formulas taking into account climatic conditions such as wind speed, temperature and pressure. By entering more digits after the comma, so by entering more accurate measures, the results become far different. He concludes that subtle variations can produce big changes.

A butterfly flapping its wings in Brazil can produce a tornado in Texas.
Edward Lorenz, 1972

Before Lorenz, Mary Lucy Cartwright and John Edensor Littlewood had observed a phenomenon as surprising, during the Second World War, about radio waves. When the amplitude of the radio waves was particularly small, their transmission became more unstable, in other words, unpredictable.

When one goes to extremely small scales, at the level of the supposed constituents of the atoms, the predictability becomes harder, and the physicists calculate probabilities of events. This is the domain of quantum physics. Some observations go as far as to defy common sense, for example the fact that a photon or an electron can behave sometimes as a wave, sometimes as a particule.

Only in the mathematical world, our conceptual world, can we produce perfect predictions. The knowledge that we have in other disciplines are simple observations from which we have identified recurrences giving us a sufficient predictability on our scale of time and space, and which can sometimes be described with mathematical formula.

Thus, no human being can fully define reality, because we are limited in what we are able to observe and to conceive. We can observe redundancies and deduce rules, they remain valid for our level of observation only, in an environment under control.