Homo Sapiens: Psychology as Seen from Evolution

By Antonio Vélez

Los temas discutidos en este libro, traducido al inglés por el australiano Kieran Tapsell, forman parte de una disciplina revolucionaria conocida como psicología evolutiva, que se ha convertido en la herramienta más poderosa descubierta por el ser humano para entenderse a sí mismo. Gran parte del conocimiento revelado por la ciencia humana se explica como resultado del proceso evolutivo, tomando como premisa la teoría de que la mayoría de los deseos, impulsos, intereses y facultades mentales humanas fueron diseñadas por la evolución de las especies. Este nuevo enfoque nos permite sintetizar un grupo ya establecido de descubrimientos, que provienen de diversas disciplinas como genética, evolución, antropología, psicología, neurología y epistemología. De esta manera es posible explicar una parte importante del comportamiento humano desde un solo principio unificado: la búsqueda directa o indirecta de una mayor eficacia reproductiva. Con este trabajo, de fácil lectura para el público general, el autor completa un ciclo de temas que comenzó con el libro Del Big Bang al homo sapiens (2004), publicado en español por Villegas Editores.

• Language: English
• Publisher: eLibros
• Release date: Aug 29, 2013
• ISBN: 9789588732718

Book preview

2009

Prologue

This book is a journey around the human being, Homo Sapiens, examining some of his behavior and explaining him from an evolutionary point of view. It tries to use a magnifying glass to look at the so called universals of human conduct, knowledge of which today is starting to set up the new and powerful discipline known under the name of evolutionary psychology. The final product is a synthesis of ideas and results already established, coming from fields as diverse as genetics, evolution, anthropology, neurology, epistemology, cognitive sciences, ethology and of course, psychology.

By universals, we mean behavior observed in all cultural studies done by anthropologists and which appear not to depend on the particular things taught within each human group. The interesting thing about the synthesis is that it turns out that an important part of the complex collection of human behavior can be explained by a unifying principle: the direct or indirect search of the greatest number of sexual partners of the best possible biological quality; that is to say, the search for the greatest reproductive efficacy.

The miraculous magnifying glass is the Darwinian theory of evolution which gives us a refreshing look at one of the oldest problems of man, that is, the reasons for behavior, the reasons for wrong behavior, for the surprises, stupidities, and contradictions, for those things running against the current of logic and common sense. The explanation which comes out is coherent with nearly everything that can be observed in human societies. And so, much of the knowledge that psychology contributes is explained as a result of an evolutionary process, on the premise that most of modern man’s desires, his impulses, interests, inclinations and mental faculties have been designed by the evolutionary process of the species to maximize reproductive efficiency.

The American psycholinguist, Steven Pinker (1977) says that man behaves as if someone is whispering inside of him what is best for his coefficient of reproductive efficacy. He says that without knowing the rules of the genetic relationship, nor the physiology of human reproduction, man has learned to behave as if he knew them, constructing systems that are directed towards the interests of evolution. What happens with foods is similar: humans naturally learn to choose nutritious things and to reject things that do not contribute calories. And they don’t let themselves be fooled.

This book says that modern man is the last link in a long and continuous evolutionary chain, in which the earlier links are animals which were becoming less and less rational as we sink back into the past. And the continuity of the chain demands that there is a certain continuity in behavior. The Austrian doctor and ethologist, Konrad Lorenz (1993) established that the human structure of feeling, thinking and acting contains innumerable historical leftovers from the era of our animal ancestors. They are leftovers that reveal themselves unpredictably. For that reason, any attempt to understand man, without having any knowledge of the species which have preceded him, is the equivalent of trying to build a house starting with the roof. The way to understand man is to understand animals, just as man himself undoubtedly appeared after having progressed along the same track as the animals. The Colombian essayist, Andrés Holguín (1998) says, with a great economy of words, The origin of man is not tied to the divine, but to zoology.

Such assumptions require man to examine animal behavior if he wants to understand himself. We first look at and analyze animal behavior, especially of the higher species that are closer to us genetically since that follows basic logic. Then we study the biological or reproductive (adaptive) advantages, taking into account natural and primitive conditions of the environment that possibly surrounded men of the past and finally we look for the mentioned behavior and its traces in man himself.

Given that it was only in recent times that we knew the details of the reproductive process, it is logical that yesterday’s man, his ancestors, and even more so, our non rational ancestors, could not understand how the devil they produced their offspring. They knew from where they came, and that it had nothing to do with the storks. It was normal for their natural impulses to point them in certain directions. On the one hand there was the urge to have the greatest number of partners, or to mate as often as possible to increase the number of heirs. On the other hand, they were impelled to defend their offspring, giving them more carriers of the family genes. As a consequence, the term, adaptive is used principally to indicate what these two purposes are trying to achieve.

When we talk about adaptive advantages in this book, this should be understood as those advantages that return the greatest amount of mating, directly or indirectly, and in the care and successful reproduction of descendants. The questions should be formulated in the past, because in life today, with high technology and great scientific development, the old natural law that the number of heirs is directly proportional to the quantity of mating, no longer applies. Besides many citizens do not want so many children any more, and they don’t have the time to bring them up and educate them. One should not lose sight of the fact that modern man is a domesticated animal, incapable of surviving if he had to return to the natural niche of his remote ancestors. Today he occupies the niche offered by the great human collectives, very far removed from where the greater part of evolution occurred. Besides, we are talking about a dehumanized niche, which is what the great collectives, the callous corporations and insensitive powerful countries really are.

In summary, every form of behavior found in modern man – the completely universal human – has adaptive functions and they are found amongst the higher species of animals. It is highly probable that they have genetic foundations. Let us not forget that genes are manifested in behavior indirectly. Hardly anyone makes love thinking of making copies of their genome, but rather does it to have fun and to satisfy their sexual impulses. They do not look after their children because they think about them passing on their genome. They look after them, says a biologist, very keenly, because they cannot avoid it. The genes achieve their "objectives’, directing the formation of neuronal nets which make sex attractive and makes people feel love and interest for their young ones, the natural fruits of sex itself.

An important and very modern subject is the spermatic struggle: semen behaves like a great organism that fights so that its owner is the one who fertilizes the woman. We continue to be manipulated by the same imperatives, looking for sex with the same intensity, independently of the fact that it is translated into more copies of our genome. This is despite the fact that reproduction in the world of today is often controlled by pills and other contraceptive methods.

Within this so called synthesis we study and put forward the thesis that we humans come into the world endowed with a considerable number of criteria for judging smell, taste, aesthetics, ethics, humor, and the dangerous. We also have a mixture of psychological characteristics that can be interpreted as archaic residues of a past that has long since gone. Cultural experiences have been added to these innate things. They modify them without making them disappear completely. The book describes and explains the different stages of sexual evolution, right up to the more complicated human sexuality. It studies the generic roles, and it tries to justify their appearance and consolidation through means of adaptive arguments. Likewise, it defends the thesis proposing the existence of an important biological component in homosexual behavior.

In the book, we agree with and support the theory of Noam Chomsky over innate linguistics and how it relates to the cerebral architecture, the recent discoveries arising from cerebral accidents and the most recent investigations over the pre-linguistic behavior of the newly born. From the field of psychology we look at Jean Piaget’s theory on the development of intelligence and we present that as the inevitable consequence of a predetermined genetic structure interacting with the exterior environment. We study the playful behavior of children and point to the importance of early stimulation for the completion of the neurological circuits. This explains naturally some astounding achievements, both physical and intellectual of some gifted people who, early in life, learned exactly those activities for which they were gifted. We take a run through the apparatus of human cognition, forged by evolution in the many centuries of adaptive change, to try to answer appropriately the niche of human beings as social animals. We study the problem of inter subjectivity and we try to explain the creativity and appearance of geniuses. Likewise, we will make a brief run through the difficult enigma of consciousness. One whole section is dedicated to studying cerebral pathologies and their strange results.

One important subject is represented by the stages of social evolution. We will show how, in this slow evolution of life through groups, some sins have appeared, like xenophobia, envy, greed, usury, the exploitation of the weak, vengeance, resentment, terrorism, hypocrisy, Manichaeism and certain unique aspects of the human species like feelings of blame, or remorse, and the sense of humor. Selfishness and altruism deserve a separate chapter. As a novelty and using an evolutionary focus, we will look at an original way of looking at economic theory, based on human nature, and not simply reason, which has given rise to a new discipline known as the behavior economics.

In addition to that, we will study some specific limitations of the human intellect, called biases, as well as other embarrassing and stupid characteristics proper to humans. Aggression, and all the things that go with it, like the impulse towards making hierarchies and territoriality, are presented as responses of an innate origin, and highly adapted in the pre-cultural past, tending to resolve a complex combination of situations created by life in community. From this picture of behavior come explanations for blind faith, the ease with which we to allow ourselves to be indoctrinated, which almost all human beings share, the conservative spirit of the old and the rebellion of adolescents, the excessive aggression of sportsmen, the violence against heretics, terrorism without boundaries, administrative corruption etc….

Almost all of the themes relating to human conduct are thorny and controversial, but none so much as the difference between the sexes. The central problem lies in the lack of equality in nature’s designs, an imbalance which, in the higher vertebrates especially, punishes the female sex by creating preferences; however, a study of man which claims to be complete, cannot ignore such important subjects, and besides, the euphemisms and hypocrisy when dealing with the subject will only create misunderstanding. Bearing this in mind, the author expects and offers apologies for certain statements which, to women’s ears might sound unpalatable.

It is not too soon to warn the reader that this book was constructed over the ruins of a first book entitled: Man: Heritage and Behavior. As well, the old book was completely demolished and reconstructed in the light of the infinity of new knowledge that has been coming in over the last two decades and that has occurred since its publication. For that reason the unsuspecting reader who knows the original book could find some subjects which sound familiar, but you can be sure that this is a fresh, modern, more ambitious and more complete book, better argued, and with greater content.

The bibliographical origins of the quotations are written in brackets with the date of the edition of the work, as they appear in the bibliography. When it is necessary, the surname of the corresponding author will also be written within the same brackets. The reader will excuse the presentation of a few quotations without bibliographical reference. The reason is that, through the disorderliness of the author, every trace of it has been lost. To help those readers who are not accustomed to biological terms, I have put in, at the end, a glossary with the scientific terms used most frequently in the book.

I want to acknowledge my appreciation of the friends and relatives who had the patience to read the originals and who helped me with their wise observations in the endless task of improving the material and reducing errors. Finally, I want to thank Villegas Editores for the work of correction and editing of the present work.

Introduction

He who understands baboons would do more

to metaphysics than Locke.

Charles Darwin, Essay on Instinct

If we wish to understand the nature

of the Universe, we have an inner

hidden advantage: we are ourselves

little portions of the universe

and so carry the answer within us.

Jacques Boivin, The Single Heart Field Theory

The history of the creation of species started around 4,000 million years ago. Our ancestors during this era were probably simple proteins – the first rehearsals for life – that started to evolve by being subjected to the filters of the original environment. Some 3,500 million years ago, the miracle of life had already occurred: the first single-cell creatures populated the aquatic environment, and they reproduced with enviable efficiency. Three thousand million years later our old relatives had acquired a bony skeleton, and dragged themselves with difficulty over the hard earth. They needed another 150 million years to become mammals and another 120 to take on the look of small monkeys. Only six million years ago, our ancestors were walking around upright. Four million years later, they were able to make rough tools of stone and bone. A million and a half years more and we already find them using fire and the ability to communicate in a primitive language so as to make a start on the dramatic ascent towards modern man.

Homo Sapiens was born yesterday. He is a product of fresh and recent evolution. He is only two hundred thousand years old or two thousand centuries, which represents some ten thousand generations. Just an instant ago, some 14,000 years in all, he started to domesticate some animals he found in his environment. He discovered agriculture, a privileged moment from which all the important cultural advances started, and that have continued in rapid succession. Culture evolves in a Lamarckian manner, that is, the accumulation of all the discoveries made in the generation before are passed onto future generations. This cultural evolution sped ahead with an explosive and amazing speed, while the evolution of body and mind continued at the slow Darwinian snail pace.

From a genetic perspective, man of today continues to be almost the same as his brother of two thousand centuries ago because biological evolution does not move in a hurry. Its seconds are measured in thousands of years and the acquired characteristics, even those that become useless, tend to last longer than is necessary. The niche, or environment in which man now finds himself, has been so completely transformed that in many important ways, modern man has become a great maladjustment. For this reason, his recently acquired rational intelligence often seems to be separate, and even in conflict with his much older emotional part. It often happens that our brain says one thing and our gut another.

We can be sure that the short period – in evolutionary terms – that separates us from the discovery of agriculture, has not been able to contribute any new hereditary characteristics to what we have inherited, or any innovations capable of molding us to the abrupt changes operating in the cultural niche that we now occupy. We can also be sure that nothing important from our old genetic makeup has disappeared completely, because the ways of biological evolution are slow and tortuous: to make and unmake things takes thousands of years. Perhaps our anachronistic genome is seriously threatening the survival of our species on which natural selection has been working continuously for thousands of millions of years. Man himself has set free forces over which he does not have control, nor does he have the ethical makeup or the appropriate intellectual equipment to cope with them.

This book is an attempt to analyze a wide variety of facets of human nature under the evolutionary prism. We apply a depth sounder to evolution in the search for behavior that ought to have been important for the survival and reproduction of our animal ancestors, and that remains within our genes through the slowness of the process itself. We will talk about the adaptive advantages that existed in the past and are not relevant anymore. We will try to explain human behavior following on the principle that reduction of everything to pure biology or to the merely cultural are both extremes without any serious foundation.

Strictly speaking, this task does not try to do more than provide speculations about human nature – sometimes simply throwing up theories as happens in a young science – supported by a rich collection of arguments set in a coherent framework. However, they are speculations that are becoming increasingly stronger with the discoveries of modern studies in human behavior. They are beginning to change dramatically the way political scientists, economists, social psychologists, anthropologists and linguists understand social and political institutions. However, we accept that these speculations are subject to discussion and revision. They will probably be modified repeatedly in that endless process that is limited by what we call the search for truth. The truth in science will always be provisional, an almost disposable object in the journey towards more precise and continuously evolving knowledge. We should then, modestly admit that we are not trying to discover the truth, but only to steal a little of it from the unknown, as Carl Sagan (1985) so well expresses it. As to the degree of truth, the Austrian philosopher, Karl Popper wrote, We can learn from our mistakes, and that is how science progresses… The history of science, like the history of all human ideas, is a history of irresponsible dreams, of obstinacy, and of error. However, science is one of the very few human activities – perhaps the only one – in which errors are systematically criticized and fairly often corrected in time. This is why we can say that, in science, we often learn from our mistakes, and why we can speak clearly and sensibly about making progress there.

In the important essay entitled The Psychological Foundations of Culture, the anthropologist Leda Cosmides and the psychologist John Tooby to whom we owe the term, evolutionary psychology, tried to look at the human psyche from the evolutionary perspective, synthesizing the best of the nativism of Noam Chomsky, the human ethology of Konrad Lorenz, and the sociobiology of Edward Wilson. Cosmides and Tooby believe that the way to understand a substantial part of the human mind consists firstly in understanding the result that natural selection was gearing towards in its design. The authors accept that evolution caused the emergence of the mind, which at the same time caused the psychological process, known as learning. Moreover, this ultimately caused the acquisition of knowledge and values that make up a person’s culture.

The psychologist, David Barash believes that we are initiating a revolution in biology, a new way of understanding why people behave the way they do. Barash (2002), says, Fortunately, this revolution is altogether nonviolent, shedding light instead of blood… and like most revolutions, this one has also been bitterly resisted by many of those who remain committed to the old ways… Thus, evolutionary theory is to biology what atomic theory is to chemistry, or the number theory is to mathematics, or gravitation theory is to astronomy.

But it is difficult to change ideas arising from old data which have become hardened by the years. We have to wait with the patience of Job. And when we really understand evolution, then and only then will we understand human beings.

William James spoke about instincts to refer to the specialized neuronal circuits that are the common heritage of all members of a species, and a product of the evolutionary path it followed. Taken together, these circuits are the basis for what is understood by human nature. It is common to think that other animals are governed by instincts, while we humans have gone beyond that and reason is our fundamental drive. We therefore think that we are more intelligent and flexible than the rest of the living world. James takes the opposite path: he argues that human behavior is more flexible and intelligent than that of the other animals because we have more instincts, not less. But we tend to be blind to them, precisely because they work with dazzling efficiency, silently and automatically and without any conscious effort.

Cosmides and Tooby state that we have a natural ability to see, hear, speak, choose the most appropriate partner, return favors, fear sickness, fall in love, initiate an attack and experience moral outrage…this is possible because we are provided with an enormous mass of neuronal webs that regulate these activities. This function of the mental machine is so perfect that we do not notice that it is there. We are blind to our instincts - the two researchers assure us – and in consequence, psychologists who have been educated in the traditional schools refuse to study these interesting mechanisms of the human mind. They remain blind to the advances in behavior science. They do not know that an evolutionary approach provides powerful glasses for correcting this blindness about our instincts. It can highlight the intricate structure of the mind.

Evolutionary psychologists accept five basic principles: a) the brain is a physical system, governed by the laws of physics and chemistry and the circuits are designed to generate behavior that is always appropriate according to the circumstances of the environment; b) the neuronal circuits were designed by evolution to resolve problems that our ancestors frequently faced during their evolutionary history; c) consciousness is the tip of the iceberg: most of what happens in the mind is hidden from us. In consequence, conscious experience can lead us to think that our circuits are simpler than they really are, so that many problems that we think are simple are really very complex and require complicated neuronal mechanisms; d) the huge number neuronal circuits are designed specifically to resolve different adaptive problems. Today, we know that there are specialized circuits in recognizing objects, physical causality, numbers, the biological world, and the beliefs and motivations of other individuals. We also know that others are designed for activities like social learning, language and diet, in detecting movement and its direction, in judging distances, in analyzing colors, in identifying other humans or recognizing the face of a friend, in looking for sexual partners and many other unconscious behaviors. We know that infants already have a well-developed system for reading minds, and that they use the movement and the direction of the gaze of others to infer what other people want. In the end, our modern minds belong to the Stone Age. For that reason, some innate behavior is not well adjusted to the world of today. Pre-cultural man could not support himself with complicated reasoning, nor was he able to consult the poor knowledge of his culture. To survive, he had to trust his instincts and to respond to the commands programmed into his mind.

From the above, we can conclude that many computational mechanisms come out of specific command centres: they are activated in some conditions and not in others. We know that the mechanisms used for the learning of language are different to those used for other matters, like disliking certain foods, and that both in their turn are different to those used in the acquisition of phobias about heights or snakes. In addition, we are not simply dealing with speculation. Many of these neuronal circuits have been discovered using scanning machines or through the clinical study of people who have suffered cerebral accidents.

These specialized learning mechanisms have their own neuronal circuits. They have the following properties: they are complex structures to resolve a specific type of problem; all normal persons have them; they develop without conscious effort; they do not require formal instruction and they are used without being aware of the underlying logic. Finally, they are different from the general ability to process information or to behave intelligently. In summary, they have characteristics that we see in instincts.

The human brain is not designed to learn calculus but it is designed for something much more difficult: learning a language when we are hardly capable of reasoning. Those who have tried late in the life know very well how hard it is, and the limitations on the final result. But if one has the appropriate foundations, a normal person can manage to learn calculus very well in a year’s study, when ten are not enough to speak a foreign language fluently.

We are plagued by anachronisms. And that’s logical: our ancestors spent 99% of their evolutionary history hunting and gathering. Homo Sapiens appears to be well designed for a past in an open field owned by nobody, with a tiny population, living in family groups or with people they know, looking for food and other resources, finding their prey, chasing and hunting them. For that reason, the cognitive mechanisms that we now have, because they were good at resolving efficiently the problems of the past, do not necessarily generate behavior adapted to our situation. We should make it clear that although the hominid line probably evolved in the African savannahs, the evolutionary environment that determines adaptation is not determined by a place or by an era. It is the statistical composite of all the selective pressures that were applied over time in the design of an adaptation. The things that explain adaptive functions are called distals as they are referring to causes that operate in past evolutionary time.

The goal of evolutionary psychology is to describe the design of what is called human nature. In this sense, it is close to psychology in that knowledge about evolution is used to discover the structure of the human mind. This new focus concentrates on and tries to answer the eternal questions about man. Is he naturally good? Are his actions governed by reason? If both nature and the environment model our personalities, what is the exact contribution of each of them? Do we have free will? Are we selfish by nature, or is it a characteristic induced by the environment? Why do we prefer to help relatives and friends before strangers? Do we have natural and hidden incestuous inclinations as the psychoanalysts propose? Are phobias, vengeance and respect for hierarchies, religiosity, and fear of certain animals natural? Are our aggression and violence induced only by culture? Is female sexuality the same as masculine?

Returning to the purpose of this book, we have to say that it is written with the full realization that it is not saying the last word, and that there is really little that we can state with certainty. We accept as a basic premise that man is the result of a continuing evolutionary process, and that his anatomic, physiological and psychological design is evolution’s achievement in resolving in the best possible way the problems of survival and reproduction. These solutions were created in the mosaic of ecological niches occupied by the animal species that preceded us, and later on by the pre-hominids – until finally we turn up. We accept that man is one more member of the earth’s fauna. There is no room for doubting his animal origins. Excluding man from the rest of nature, as some try do, is to resign oneself to failing to understand him fully.

Natural selection is supported by only one criterion: reproductive efficacy. It has to be measured differentially, that is, with respect to that of the competitors. Evolution not only deals with winning, but in winning more than the others, and, on occasions, making the others lose. Evolution, for that reason will always be producing evil people. A practical way of analyzing it, although it is only an approximation, is by looking at the amount of mating. Evolution tries to maximize the amount of an individual’s and his relatives’ mating above the rest. This is the key to the centuries old problem that has escaped the observations of so many thinkers of the past: human nature is so perplexing and appears to be so contradictory. For example, a whole variety of human behaviors, like nepotism, are based on selfishness. Some of these behaviors we brand as plain immoral from the perspective of the human soul. But it is the human soul that causes them all.

We have to understand that the search for the greatest reproductive rate appears to be disguised as something else. Nearly the whole effort of this book will be directed towards looking behind the masks that cover up this search. Sometimes they are emotions, drives, attractions, rejections or inclinations that take us in certain directions and take us away from others. They encourage us to prefer certain conditions and reject or move away from others, to interest ourselves in certain types of learning and to be disinterested in others.

The struggle for greater status is a disguise for the search for the greater number of descendants, amongst other things. So is the unstoppable and unlimited desire to acquire goods; and extreme aggression in the face of certain conditions in social life; so is the injustice in the treatment of others, in the biological sense, who carry very different genomes to ours; so is the sexual injustice that demands polygamy for oneself and monogamy or no partner at all for others; so is the hoarding of sexual partners, or polygamy; so is xenophobia, poisonous envy or unbridled avarice. All of these, that in past ages when human nature was being formed, meant a greater number of descendants as a result. This whole idea of a greater number of descendants is no longer valid, but equally, our genes do not learn so quickly. They continue to guide us in directions that appear mistaken from a rational point of view.

An animal that is perfectly altruistic, that always gives up his turn for his companions, that does not hoard critical resources when the opportunity presents itself, that does not respond violently to aggression or to injustice, that does not seek vengeance, that is not interested in sex, that works ceaseless for his relatives’ good, and that does not gorge himself when times are plentiful - this animal will not leave descendants, or will leave very few in comparison with his companions in the group. On the other hand, the lecherous, the egotists, the ones who are altruistic towards their closest relatives, the opportunists, the aggressive ones, the Machiavellis, the greedy, the miserly, will have and will leave more descendants. Consequently, these virtues will be chosen by natural selection to be incorporated in the biological package of every species even though they are sins from the human perspective. And man is no exception.

It should now be clear that man has not been designed by Heaven but by the Earth. Emil Cioran caustically says that apart from some aberrations, man is not inclined towards the good. The truth is that we carry in our souls both angels and demons. Evolution is selfish by design. It brings us the demons. Culture brings us the angels, sometimes, it is true, ready to correct or control the impulses of the first. By example, specific teaching, and the effects of culture, some men manage to control these bad genes and to behave within civilized moral norms. This design of man, absurd as it seems, has confounded the great philosophers throughout the ages. Only now, in recent times, have we begun to understand human nature, because of a few thinkers on animal behavior who have been inspired by the theory of evolution as the backdrop. The contradictions and strange things in human behavior have now been explained in this way. However, there still remain many studies of man that do not accept these ideas and continue to think that we are the exception to the rigid rules of natural selection. They think that man is the good man of the philosopher, Jean Jacques Rousseau, able to be molded perfectly by the forces of culture, but perverted by his environment. They think he has a blank mind at birth on which his environment writes. It is the educational system that pushes him into using dirty tricks to get his own way.

If we understand the above, we can begin to understand the history of man, his contradictions, his virtues and sins, and his nature. We can start to understand why so many attempts to group men into religious, social and economic systems have failed. They have proceeded from the assumption – a false one – that human nature is something that can be molded voluntarily, free from innate components that are resistant to change.

We should never forget that every man is the final product of two types of learning: the phylogenetic realized by the species in its long evolution, and the individual or biological, generated during the very short period of time during which the individual lives. The first is distinguished from the second in that what is learned cannot be forgotten – Lorenz’s words – or it is almost impossible to acquire it on purpose. This means that man is subject to two commands: the irrational or the unconscious, written in the genetic program before birth, and the rational or conscious, written after birth through all his cultural experiences. But rational control, which we all hope is the commander in chief of our actions, sadly hands over the conductor’s baton to the irrational and the emotive in a great many of our decisions.

For that reason, man is a paradox: while one I pushes him to fraud, the other rejects it. Sometimes, but rarely, the second wins and this is what consists in being civilized. Notwithstanding frightening evidence, we have a strange opposition to accepting the existence of powerful and different commands to those generated rationally. Thirty or more centuries of listening to the arguments of philosophers, politicians and religious reformers has only blocked us from the path of understanding. It is therefore the duty of civilized man to turn this idea on its head. It is a very flattering view of course, that he has about himself.

Steven Pinker maintains that the most important discovery in psychology is very recent. It involves outlining the great importance of genes in determining human personality, much more important than cultural factors. Rigorous comparative studies of pairs of identical twins, fraternal twins, and natural and adopted siblings have demonstrated that genetic factors have the greatest weight in the determination of personality. This means that we should not say, tell me with whom you keep company and I will tell you who you are but "tell me who you are and I will tell you with whom you keep company." At the same time, these studies have found that there are other factors difficult to pin down, that appear to be random for the moment, and just as important as the genetic ones. The point that Pinker emphasizes is very important but it appears to be more correct to say that the high point of psychological discovery is using the evolutionary prism to see through the human psyche. Without this vision, every attempt to understand humanity will finish in complete failure.

We will not speak in this book about nature or nurture, but more about nature and nurture. It is incorrect to say that a man is born the way he is, just as it is equally incorrect to say that he makes himself. A man is both born and he makes himself. This is the position that we will try to defend. The author believes firmly that those who look at man as the son only of his cultural environment, or see him only as a purely biological being, will only arrive at discovering a part of the truth, and a part of the truth, as the English philosopher, Bertrand Russell wisely wrote, is often a huge lie.

We have to recognize that the predominant opinion of professionals in the social and human sciences, starting from the third century, and even at this moment of great scientific development, adheres to the dogma that states that human behavior is almost entirely a product of nurture, of learning and social tradition. Part of this opposition is due to a misunderstanding of the evolution of the species, its criteria and its consequences. When the opposing view refers to these subjects, they point out immediately its faults. Paraphrasing Winston Churchill: never have so many said so much over something of which they understand so little.

There has been a real aversion to biological explanations or reductionist ones as the social scientists contemptuously call them. This has been most unfortunate for the advance of the social sciences. The most virulent attacks on the introduction of the biological into human behavior have come from several camps: psychoanalysts, behaviorists, Marxists, religious people, humanists and feminists. All of them feel a natural antipathy for the innate, in total disagreement with the discoveries made in the last three decades. As they are petrified in their old ideas, there is nothing that can be done. They will take them to the grave.

Against the evolutionary ideas about human conduct, there are the defendants of the so-called, Social Standard Model, a fusion of ideas taken from anthropology and psychology. The model assumes that while animals are controlled rigidly by their biology, humans are controlled by our culture. This consists in an autonomous union of values, free from biological restrictions that can vary arbitrarily from one community to another without any restrictions. The model assumes also that children are born with certain reflexes and an ability to learn. But it is a type of learning without any special biases, open to all kinds of influences and used in every field of learning. For the defenders of this 1920 Model T Ford, children learn their culture through indoctrination, through rewards and punishments and through imitation or inducement and copying their elders. According to the Social Standard Model, culture extends through the community like a contagious illness spreading from person to person, and language is the carrier loaded with this contagion.

These dreamers argue that the human animal has been liberated from the slavery of the instincts and acts to great extent in accordance with the norms imposed by its culture. For many of these bright thinkers of today, the biological study of innate human psychological characteristics is not only uninteresting, it is absurd. In a bibliographical review, the sociologist Alan Wolfe wrote that the biologization of the human being is not only bad humanism, but also bad science. And the defense of these ideas takes place with unusual aggression, a fact which one can predict from the same biological perspective of human nature that they deny.

Studies that focus on the evolution of human nature met with the same rejection that Copernicus and Darwin suffered. Human beings were disgusted by the way in which they were being displaced from the centre of the universe. The very fact of trying to study human behavior on an equal standing with other animals is taken as an insult just as it was an insult to accept that the Earth was just one of several planets in the solar system and not the biggest.

We have to recognize that part of the opposition to the evolutionary study of man arises from fear that the genes alone determine what is human. There is a genuine fear of a discredited genetic determinism. But this is a big mistake and it comes from a bad understanding of the form in which genes act on behavior. Konrad Lorenz (1986) does not agree with these critics. He says that in the light of the Darwinian theory of evolution, the thesis that humans are not the results of biology has never appeared very plausible. He suggested that the time had arrived to abandon it definitively, that human action and thought are formed and structured by biological factors and that natural selection and the adaptive advantages have become the central nucleus of our being.

In another book, written together with his colleague Niko Timbergen (1986), Lorenz said that ignoring questions about the value of survival and evolution – as for example, most of the psychologists do – not only shows short sightedness, but it makes it impossible to arrive at an understanding of the problems of behavior.

When we talk about a human characteristic, we are not suggesting that all men have it to the fullest. If we say that man is selfish, it does not mean that all of us are consummate egoists. Selfishness and all sins and human frailties come in all sizes, from the smallest S to the largest, XXL. The variability is very wide, but the majority of us are M. In all features of human beings, we find dwarfs and giants, idiots and geniuses, the ugly and the beautiful, silly people and very sharp but dishonest people, radical atheists and fervent believers, people without fingers, others with additional fingers, people with the normal complement of 32 teeth, and others like the Mongols, a complete ethnic group with only 28 (in general the wisdom teeth don’t appear). We have races, like the Nordic races of Europe, with a high tolerance for digesting milk, or those with a low tolerance, as is the case of the majority of Chinese, or practically no tolerance at all, as occurs with the Eskimos and Polynesians.

Almost all important human characteristics show a variability which can be represented very well by the normal distribution or Gauss’s bell, (figure 1). The majority of humans, those called normal, people without marked attributes and those with lots of them, make a bulge in the centre part. Others are the very few (less than 0.3%) who are the saints and the demons in the two tails. When, for example, the morality of an individual falls into the extreme of bad, his sins, expanded out, are not adaptive or attractive anymore. They are not only prejudicial for the group, but also for the individual himself, and natural selection tends to weed out the bad seed for that reason.

Figure 1. The normal distribution of Gauss’s bell describes relatively well the statistical distribution of many human traits. The area of the curve –as a percentage – is understood as between one and minus one standard deviation from the median. It is about 68.3% and corresponds to what we call normal. The area of the two tails, situated outside the three deviations, that is, the percentage of extreme cases, the very rare ones, is only 0.3% of the population. Any trait that wanders one standard deviation away from the mean is considered a big deviation, two deviations is very big and three is enormous".

Figure 2. Charles Darwin, father of the theory

of evolution. (Image: Shutterstock/Nicku)

1. Evolution

Darwin’s theory of evolution is the only theory

we have come up with so far that can explain

the illusion of design in causal terms.

Steven Pinker

Annual meeting of the Freedom

from Religion Foundation,

Madison, Wisconsin, October 29, 2004.

Man is a microbe that has come a long way.

Anonymous

Most biologists agree that the evolution of species is the process through which genes become more numerous in the genetic heritage of a population, at the expense of others that reduce in number. For Konrad Lorenz, the evolution of living organisms is nothing more than the acquisition and storage of information about the environment. Thus the fetus, still in its mother’s womb, will take with it very valuable knowledge within its own structures about the environment in which it will have to survive. From the time the humming bird breaks out of its shell, it will have a beak designed exactly for the type of flowers that will provide it with food. The horse’s hoof, says Lorenz, presupposes the form of the grasslands without it having taken a step, and fish’s fins are designed in advance to take advantage of the hydrodynamic properties of water.

The term, evolution is associated with adaptation and with the progress and improvement in organisms by increasing their organizational complexity. Evolving in general means that certain characteristics spring up naturally to give the greatest efficiency in the execution of the tasks that are typical for the individual. These characteristics are the best adjustment with the external environment, the best use of energy, more autonomy and control over the environment, and greater economy and excellence in design.

The essence of the theory of evolution of species, set out by Charles Darwin and independently and almost simultaneously by Alfred Russell Wallace, continues to be current thinking. The evolutionary process comes about from two opposing mechanisms. The first is the creation of hereditary variations that nature itself provides. The environment provides the second in the ecological niche that brings about the selection. The model is breathtakingly simple. It can explain in a few lines the highest level of complexity known on this planet, the complexity of life. Even more than that, it is the only mechanism known that can generate complexity spontaneously, to the point where it creates an illusion that behind everything is an intelligent designer.

THE DARWINIAN MODEL

One easy way of understanding the essence of evolution is to observe what happens on a farm – Darwin was inspired by what he saw. Farming has shown in real life the process by which man has managed to modify significantly for his own benefit, a broad collection of animal and vegetable species in just one hundred and forty centuries. The successes of this procedure, known as artificial selection, have been numerous and momentous in the evolution of human culture. In only 14,000 years of domestication from the wolf, man has obtained a wide variety of breeds of dogs, some as different in shape and size as the miniature pinscher and the St. Bernard. Leghorn hens in 1930 laid an average of 120 eggs a year. Now they lay more than 300 a year. A Friesian cow is a machine for producing milk. Many of them produce the astounding quantity of 80 litres a day.

Figure 3. Alfred Russel Wallace, coauthor, with Charles Darwin of the theory of evolution.

(Image: http://en.wikipedia.org/wiki/File:Alfred_Russel_Wallace_-_Project_Gutenberg_eText_14558.jpg)

Evolution occurs by means of the Darwinian evolution machine that is made up of the same mechanisms that the farmer uses to improve his animals: variation and selection. The first adds the second keeps it. Individual carriers of hereditary novelties appear. They can be anatomical, physiological or psychological, and their principal causal agents are variations in the genetic material. These genetic collections improve the reproductive efficacy in the niche occupied by the species by maintaining stability. They will tend to propagate themselves in the population to the detriment of other alternatives in a competition called natural selection. To survive in the world is like a lottery: greater reproductive efficacy is the same as having more tickets. The genetic material of the winners and its particular characteristics spreads throughout the population, and finishes up forming part of the features of the species. The biochemist, Steve Jones (1998) says that evolution is like an examination in two subjects. We have to pass both to get through. The first test is to stay alive long enough to have the opportunity to reproduce ourselves. In the second, the mark depends on the number of descendents. Those who do not get to adulthood or do not leave descendents, miss the evolutionary year.

Darwin speculated that if by chance an individual in a population were better adapted than its companions to survive in the environment that it occupies at the time, it would tend to leave more descendants than the others. For that reason, in the classical model, we talk about fitness, as a way of measuring the capacity for survival of the progenitor and its heirs. That translates in the end into a greater number of descendants.

It happens often enough that people who have studied the Darwinian model for the first time have been confused by the concept of adaptation, as they almost certainly have observed a profusion of non- adaptive characteristics in living things. Darwin himself, after the publication of Origin of Species realized this deficiency. He had to modify his model, introducing what he called "sexual selection", an indispensable complement to his coefficient of fitness. Darwin reasoned liked this: if a particular individual, because of his attractive feathers has great success with females, or because of his greater physical size, or the length and strength of his horns, can defeat his rivals and appropriate to himself a numerous harem, the disadvantage of a greater vulnerability, if he has it, is compensated by increases in a greater reproductive rate. In short, he has a shorter life span but a more pleasant one.

SEXUAL DIMORPHISM

When evolution wants reproductive capacity, natural selection turns into sexual selection. The greater size and profusion of decoration in the males of several species bears witness to a common occurrence in the evolution of mammals. Although greater size in some conditions represents a lack of adaptation, it serves to give access to more sexual partners: the decorations that make it sexually more attractive. This morphological asymmetry is known by the name of sexual dimorphism. Lions are stronger and more robust than lionesses, and in addition, they have imposing manes; the male West African baboon is double the weight of the female, and the same thing occurs with gorillas and orangutans. The male sea lion is disproportionately much larger than the female. In the human species and amongst chimpanzees also, there is dimorphism, although it is moderate; the females have approximately 80% of the weight and size of the males.

Figure 4. Sexual dimorphism is over the top with sea lions. In the photo, a male is watching over the possession most appreciated by his genome: the harem. (Image: Shutterstock/Manamana)

Brilliant decorations, colors and apparatus are a visual resource with which males attract females, but they also attract predators, because the ornaments make them stand out more and become more visible. In the same way, overloaded plumage increases their vulnerability to predators. Endocrinologists say that it is associated with high levels of testosterone that provide undesirable immunosuppressant effects. However, given their proven biological success, they must have gained more by their greater attraction to the opposite sex, than what they have lost to the jaws of carnivores, or by being plagued by infections. Luxurious plumage would be a clear lack of adaptation, but it brings them a greater amount of mating, with a balance in their favor: a greater number of offspring. This implies that the fittest do not always survive.

SOURCES OF VARIABILITY

Biological variability comes about from alterations in any of the components of the system that supports life and includes genetic and environmental factors. We will explain how the cell’s primary function is to be under the command of genetic instructions, but the laws of physics and chemistry produce certain effects that do not depend on such instructions. In all cases, the genes use the laws of physics to carry out and promote their functions.

The development of an organism is a complex process that inseparably involves the genes and the environment. The genome is like a symphony score, that molds the result, but the conductor of the orchestra, the musicians, the instruments and the building are fundamental to the final result. The mathematician, Ian Stewart (1999) summarized it by saying that genes are not a detailed plan. They are like a recipe. The cell carries out its genetic instructions. The laws of physics and chemistry produce certain consequences and when you combine them, you get an organism. The genes complete the laws of physics; they do not replace them nor overcome them. For that reason, we now talk about epigenesis, originally a biological concept, to refer to the development of an organism under the joint influence of heredity and the environment.

And when we talk about environment, we can be dealing with the cell (the complete organism in single cell creatures, and the egg or ovum in multi-cell creatures), which is a particular entity at the disposal of its owner alone. Or, we can be talking about the uterus of mammals, also the private property of its owner. We can be talking about the external environment, affecting everyone. There can be different proteins in the same gene, according to the environmental conditions. Sometimes the final product depends on the type of cell in which the reading of the gene is carried out. That is, the environment affects the end result , but the reading of the genetic code depends on the environment in which it is expressed. For example, in caimans, crocodiles and lizards, the incubation temperature of the environment determines the sex, in such a way that high temperatures give rise to females; low temperatures to males. In the same way, during the development of the embryo information from neighboring cells is used, that is, the development also depends on the cellular context.

Another important factor that participates in this development is a collection of proteins called epigenomes that accompany the genome and carry out a prominent role in the final expression of the genes, as they act to accelerate or to put a brake on the action of some of them. There is speculation that the epigenomes are what causes sicknesses that affect identical twins in very different ways, like schizophrenia, bipolar disease and cancer. Although identical twins, at birth, possess the same epigenome, on growing up they create differences as a response to the forces of the environment.

The number of genes that constitute the human genome is no more than 25,000, a figure well below our expectations, given that to be a human being is to have considerable complexity (it is calculated that the human proteome, that is to say, the collection of proteins produced in the organism of man, is formed by 100,000 of them). But they have discovered that such a low figure hides a surprise, as more than three quarters of the genes possess a multiple personality, that is, they give rise to several different proteins that explode the number of functional units (Ast 2005). Like good magicians, from one sole gene, nature takes several rabbits out of the hat.

The function of some genes consists exclusively in putting some of them into action and in blocking others. It is not then necessary to invent more genes to bring about important transformations in the phenotype, but all that is required is to block or activate them, following intricate guidelines that they already have. It can happen that they activate one gene, that in its turn activates another, and this one, in turn, blocks the action of a third and this one of a fourth…., These sequential functions can increase astronomically, in an explosion of numerous combinations from about 25,000 of these human genes. This resolves the enigma of why an apparently small number of genetic instructions are codified in creatures of such complexity.

The richness of genetic variability is fed from various sources. Amongst the principle ones are the mutations that occur as much in the nuclear DNA as in the organelle. Second, there are the genetic combinations resulting from the reproductive process in those species that cross sexually. Third, there is the crossing over or genetic recombination, a process of interchanging genes between homologous chromosomes that occurs during meiosis, the cellular division that gives rise to gametes. Fourth and finally, there is the transference of genetic material between individuals, the principal source of diversity in single cell organisms, and whose existence has been proved in other species, including humans.

The variations or novelties of DNA appear by chance. Often, they translate into defects, or the carrier does not receive any biological benefit, and the novelty therefore disappears. On other occasions, they improve the reproductive qualities of the carrier. If the happy improvement is not lost by accident, the genetic pool of the population will go on being enriched in those genetic collections that possess the fortunate mutation. It is then said that the species is evolving because, strictly speaking, to evolve means to modify the genetic heritage of the population. It is important to point out that in the process just described, there is nothing certain or determined beforehand. It can happen that the novelty, notwithstanding that it improves the reproductive rate of the individual carrier, will disappear without trace because of an accident, an inopportune infection or significant climate change.

SELECTION CRITERIA

The term fitness is unfortunate. Although it is closely related to reproductive efficacy, the crucial factor in the evolutionary process is not the same. And, it is true that to have a high reproductive efficacy, its anatomy, physiology and psychology must fit in with, and be consistent with the ecological niche that it occupies, that is to say, it needs to be better adapted to the environment. But this is just the beginning. It is a necessary condition, but that is not enough. An individual may be well adapted to his environment but he may not have access to partners or he may be sterile, in which case his reproductive efficacy is nil. Or, he can be perfectly adapted and be very successful with partners, but at the same time he may be very careless about his offspring, which lowers his net reproductive efficacy. Evolution has as a supreme commandment, one that must be respected: save your skin or your kin (Barahs 2002).

Darwin recognized very early that his evolutionary model was not capable of explaining the appearance of altruistic behavior. It seems to be a negative factor, showing a lack of adaptation, because in some ways it operates against the reproductive efficiency of the individual himself. To remedy this defect, the evolutionist William Hamilton proposed to add the so-called, kinship selection or inclusive fitness to the original model. The idea behind this factor of selection is that any mutation that favors altruistic behavior for the benefit of relatives involves the carrier investing its already existing biological resources in caring for its young or in helping all of those who are carriers of similar genomes to his own. This mutation will have better possibilities of being propagated in the population because a certain proportion of its direct relatives will also be carriers of the same altruistic mutation.

One way of making sure that the concept of adaptation does not lead to errors is by including three factors in the idea of the coefficient of reproductive efficacy. They are the three fundamental factors of biological success: first, adaptation, or the adequate adjustment of the organism to its present ecological niche; second, effective and long term fertility, or the capacity to give birth to fertile, healthy and also well adapted offspring; third, the capacity or willingness to invest biological resources in descendents and in near relatives, virtues known under the name of family altruism.

We should not forget that reproductive efficacy is a relative