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Are child prodigies a result of nature or nurture? Is intellectual giftedness is nothing more than good genes or the result of an encouraging environment? Let's read on to check the facts.....
Nature vs Nurture

Professors are inclined to attribute the intelligence of their children to nature and the intelligence of their students to nurture.-Roger Masters

"Nature versus nurture" is a debate related to whether heredity or the environment most impacts human psychological development such as behavior, habits, intelligence and personality. It's obvious that you share your parents' DNA in the physical sense like you might have blue eyes like your father but it is difficult to explain your love of writing poetry or being a talented football player in the same way. The theory of genetic predispositions is known as the "nature" theory of human behavior and the theory that people think and behave in certain ways because they are taught and trained to do so is known as the "nurture" theory of human behavior. The understanding of the human genome has made it clear that Nature endows us with innate tendencies and Nurture enables expression of these genetic tendencies as we respond, adapt, learn and mature. People who take the position that all or most behaviors and characteristics are the result of inheritance are known as nativists, where as people who take the position that all or most behaviors and characteristics are the result of learning are known as empiricists.

What does your genome say about who you are? Genes allow human mind to learn, to remember, to imitate, to absorb culture and express instincts which are the cause as well as the consequence of our actions.
Light from many lamps:

The phrase 'nature and nurture' is a convenient jingle of words, for it separates under two distinct heads the innumerable elements of which personality is composed -— Sir Francis Galton

According to Matt Ridley as mentioned in his book "Nature via Nurture" , human nature is a combination of Darwin's universals, Galton's heredity, James's instincts, De Vries's genes , Pavlov's reflexes, Watson's associations, Kraepelin's history, Freud's formative experience, Boas's culture, Durkheim's division of labor, Piaget's development and Lorenz's imprinting. No account of human nature would be complete without them all.

In order to understand each and every one of them we need to understand genes which allow the human mind to learn, to remember, to imitate, to absorb culture and express instincts which are the cause as well as the consequence of our actions. They were right in the sense that they contributed an original idea with a germ of truth in it; they all placed a brick in the wall. They are wrong only when they try to pull somebody else's bricks out, or to claim that the wall is held up only by their bricks.

Examples similar to nature vs nurture debate Nile is actually the sum of thousands of streams and none of them can be truly called its source; the same is true for human nature and with few insects like butterfly.
Nature vs Nurture debate:

This debate is similar to the dispute between English explores regarding source of Nile. The river Nile is actually the sum of thousands of streams and none of them can be truly called its source; the same is true of human nature.

When as by a miracle, the lovely butterfly bursts from the chrysalis full-winged and perfect...it has, for the most part, nothing to learn, because its little life flows from its organization like melody from a music box. - Douglas Alexander Spalding

The nature side of this debate emphasizes how much of an organism reflects biological factors. A few examples of biologically determined characteristics (nature) include - eye color, hair color, and skin color and certain genetic diseases. Life expectancy and height have a strong biological component, but they are also influenced by environmental factors and lifestyle. An example of a nativist theory within Psychology is Chomsky's concept of a language acquisition device ( LAD). According to this theory, all children are born with an instinctive mental capacity that allows them to both learn and produce language. Emil Kraepelin was a pioneer in the development of psychiatry as a scientific discipline. He was convinced that all mental illness had an organic cause, and he was one of the first scientists to emphasize brain pathology in mental illness.

I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection. - Charles Darwin

William James believed that human beings are equipped with innate tendencies that were not derived from experience but from the Darwinian natural selection . He argued that reason could make an inference which will excite imagination so as to let loose the impulse and hence the animal richest in reason might also be the animal richest in instincts. He asserted that human beings have more instincts than animals.

Empiricists believe the outcome of a person's destiny depends on where they live The balance of nature and nurture in influencing how a child grows up varies depending on where they live, according to a new study.
View of Empiricists

The view of Empiricists that humans acquire almost all their behavioral traits from "nurture" was termed tabula rasa-"blank slate" by philosopher John Locke.. Nurture refers to our childhood, social and environmental factors. The supporters of the nurture theory believe that our behavioral aspects originate from the environmental factors of our upbringing. Harvard psychologist B. F. Skinner's early experiments produced pigeons that could dance, do figure eights, and play tennis. Today known as the father of behavioral science, he eventually went on to prove that human behavior could be conditioned in much the same way as animals. Studies on infant and child temperament have revealed the most crucial evidence for nurture theories. American psychologist John Watson, best known for his controversial little Albert experiments with a young orphan named Albert, demonstrated that the acquisition of a phobia could be explained by classical conditioning.

Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select – doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors." – John B. Watson

How do attachments develop – Is it by Imprinting? Imprinting is a genetic phenomenon that occurs in animals during their first hours of life, and theoretically in humans, too. In humans, this is often called bonding and usually refers to the relationship between the newborn and its parents. Most criticisms of the imprinting or critical period theory however, are based on its application to humans.
Principle of imprinting

Lorenz coined the concept of critical period – the window during which environment acts irreversibly upon the development of behavior. For Lorenz, the importance of imprinting was that it was itself an instinct. Konrad Lorenz , while working with geese, rediscovered the principle of imprinting (originally described by Douglas Spalding in the 19th century) in the behavior of nidifugous birds. In his classic experiment with newly hatched goslings (baby geese). For this experiment, Lorenz split the eggs from the same goose into two, randomly-picked groups. Group A hatched in a natural environment and immediately began to follow mother goose around. Group B hatched in an incubator and the first living being they saw was Konrad Lorenz. So they immediately began to follow Mama Lorenz around… All the time.

Our problem, from the point of view of psychology and from the point of view of genetic epistemology, is to explain how the transition is made from a lower level of knowledge to a level that is judged to be higher.-Jean Piaget

Jean Piaget saw a progressive, cumulative construction of mind during childhood in response to experience. Each child goes through a series of developmental stages always in the same order, though not always at the same rate. Piaget saw cognitive development neither as learning, nor as maturation but as a combination of the two, a sort of active engagement of the developing mind with the world. He thought the mental structures necessary for development are genetically determined, but the process by which the maturing brain develops requires feedback from experience and social interaction. This feedback take two forms: assimilation and accommodation. A child assimilates predicted experiences and accommodates to unexpected ones.

Infinite possibilities of human nature A culture led process acting over a long period of human evolutionary history , could easily have led to a fundamental reworking of human psychological dispositions.
Expanded form of human nature

According to Sigmund Freud, the naive self-love of men has had to submit to two major blows at the hands of science. The first was when they learnt that our earth was not the center of the universe but only a tiny fragment of a cosmic system of scarcely imaginable vastness... the second blow fell when biological research destroyed man's supposedly privileged place in creation and proved his descent from the animal kingdom and his ineradicable animal nature… But human megalomania will have suffered its third and most wounding blow from the psychological research of the present time which seeks to prove to the ego that it is not even master in its own house, but must content itself with scanty information of what is going on unconsciously in its mind.

A person is not merely a single subject distinguished from all the others. It is especially a being to which is attributed a relative autonomy in relation to the environment with which it is most immediately in contact.- Emile Durkheim

Franz Boas stresses the plasticity of human culture and expanded the human nature into an infinity of possibilities and pointed that culture is what set people free from their nature. A culture led process acting over a long period of human evolutionary history, could easily have led to a fundamental reworking of human psychological dispositions. Culture thee by co-evolves hand in hand with real genetic evolution. Susan Blackmore argues that many ideas and units of culture are sufficiently enduring, fecund and high-fidelity and that they therefore compete to colonize brain space.

The Big five personality traits These are five broad domains or dimensions of personality that are used to describe human personality.
Research studies:

Behavior geneticists distinguish shared family factors (i.e., those shared by siblings, making them more similar) and non-shared factors (i.e., those that uniquely affect individuals, making siblings different). The variance due to the "nature" component generally refer to the heritability of a trait. Judith Harris argues in her book that "nurture," as traditionally defined in terms of family upbringing does not effectively explain the variance for traits such as adult IQ and the Big Five personality traits.

The Big Five personality traits are openness, conscientiousness, extraversion, agreeableness, and neuroticism. These personality factors were consistent across cultures, and many experiments have also tested the heritability of these traits. Identical twins reared apart are far more similar in personality than randomly selected pairs of people. Identical twins are more similar than fraternal twins. Biological siblings are more similar in personality than adoptive siblings. The variation in personality is due to a combination of genetic factors, shared environmental influences and unique environmental influences experienced by individual and yet genetic factors play a dominant role.

Research studies estimate that the contribution of shared environment to variation in IQ in a Western society is roughly 40 percent in people younger than 20 and then falls rapidly to zero in older age groups. Conversely the contribution of genes to explain IQ variation rises from 20 percent in infancy to 40 percent in childhood to 60 percent in adults and may be even 80 percent in people past middle age. It reveals that intellectual experience of a child is generated by others ,where as an adult generates his or her own intellectual challenges. The environment is a unique set of influences chosen by the actor himself. [soruce: www.neoeugenics.net/nvn]

A twin approach to unraveling epigenetics Rapid advances in the field of epigenetics are now revealing a molecular basis for how heritable information other than DNA sequence can influence gene function.
Insights from identical twins

Studies cover siblings who are identical twins reared together (share family environment and genes), fraternal twins reared together (share family environment but only share half their genes) and adoptive siblings (share their family environment but none of their genes) and biological siblings reared together ( share the same family environment and half their genes). I n many cases, it has been found that genes make a substantial contribution and yet heritability may differ due to wide variation in environmental conditions. The variability of trait can be meaningfully spoken of as being due in certain proportions to genetic differences ("nature"), or environments ("nurture"). The field of epigenetics adds new fuel to this issue by shedding light on how environment, nutrition and social conditions affect how genes are expressed.

Personality is about as heritable as body weight. The correlation between siblings in weight is 34%. The similarity between parents and children is a little lower, at 26%. Identical twins reared in the same family have a correlation of 80% while fraternal twins reared together have only 43% similarity, which suggests that genes matter more than shared eating habits. What about adoptees? The correlation between adoptees and their adoptive parents is only 4%, and between unrelated siblings in the same family it is just 1%. By contrast, identical twins reared apart in different families are still 72% similar in weight. [source: Nature via Nurture – Matt Ridley]

Genetic diversity in a species allows it to adapt to changing environments. Genetic diversity is the variation of heritable characteristics present in a population of the same species. It serves an important role in evolution by allowing a species to adapt to a new environment and to fight off different circumstances.
Genes and Environment:

According to Matt Ridley, Genes can be defined in seven different ways: Mendelian archive(inscribed with the wisdom derived from millions of years of evolutionary adjustment);a Watson-Crick recipe(achieving its effects through creation of proteins via RNAs); a Jacob-Monod developmental switch (expressing itself only in precisely specified tissues); a Garrodian health giver(ensuring a healthy developmental outcome in the expected environment );a De vriesian pangen(reused in many different developmental programs in the same species and in others); Dawkinsian gene with attitude (in its dependence on passing the test of survival through the generarion) and finally the Tooby-Cosmides gen which integrates all the above six and defines the gene as device for extracting information from the environment . They are exquisitely good at simple if-then logic: if in a certain environment, then develop in a certain way.

Heritability refers only to the degree of genetic variation between people on a trait and does not refer to the degree to which a trait of a particular individual is due to environmental or genetic factors. At a molecular level, genes interact with signals from other genes and from the environment. While there are many single-gene-locus traits, many other traits are due to the additive effects of many genes. A good example of this is height, where variance appears to be spread across many hundreds of loci. Multivariate genetic analysis which examines the genetic contribution to several traits that vary together, has demonstrated that the genetic determinants of all specific cognitive abilities such as memory, spatial reasoning and processing speed overlap greatly, such that the genes associated with any specific cognitive ability will affect all others. Multivariate genetic analysis has found that genes that affect scholastic achievement completely overlap with the genes that affect cognitive ability.

Schizophrenia, Phenylketonuria are the examples of gene-environment interaction Genetics and early environment, appear to be important contributory factors for these diseases.
Examples to show gene-environment interaction

The incidence of disorders such as Huntington's disease is entirely due to genetic differences.. At the other extreme, traits such as native language are environmentally determined. However a trait is mostly shaped by both genetic dispositions and the environments in which people develop as environmental inputs may affect the expression of genes . Genes and environment work in concert, communicating back and forth to create the individual.

A classic example of gene–environment interaction is the ability of a diet low in the amino acid phenylalanine to partially suppress the genetic disease phenylketonuria. The situation is more complex in the case of Schizophrenia (a mutation in the gene Neuronal PAS domain protein 3 (NPAS3) is in some way responsible for the development of mental illnesses such as schizophrenia.) where many different genes and many different environmental factors are involved. The more you discover genes that influence behavior, the more you find that they work through nurture, and the more you find that we learn from the environment, the more you discover that learning works through genes.

The happiness gene The serotonin transporter gene (5-HTTLPR) is called "happiness gene", as variation in the promoter region of this gene influences the feeling of happiness.
Gene Expression:

The genes are activated at appropriate times during development and are the basis for protein production. Proteins include a wide range of molecules, such as hormones and enzymes that act in the body as signaling and structural molecules to direct development. The product arising out of the expression of one gene may turn up the expression of another, which suppresses the expression of a third and so on.

External factors like education, food, conflict or love may enter right in the middle of this network to influence the so called thermostats on the fronts of genes which affect the timing. We can see nurture express itself through nature. Genes are the means by which nurture expresses itself, just as they are means by which nature expresses itself. The oxytocin receptors expressed in the medial amygdala fire up the dopamine system with sensations of personal addiction towards the loved one and hence pair-bonding instinct is manifest in oxytocin receptor genes. The serotonin transporter gene (5-HTTLPR) is called "happiness gene" as variation in the promoter region of this gene influences the feeling of happiness.

Sex-determining region Y (SRY) – Gene for maleness The SRY gene provides instructions for making a transcription factor called the sex-determining region Y protein. The sex-determining region Y protein causes a fetus to develop as a male.

FOXP2: A genetic window into speech and language Tiny changes in the FOXP2 gene may have helped humans develop language. FOXP2, the most intensively studied gene associated with language.
Examples

SRY Gene:

SRY gene which is considered a gene for "maleness" switches another gene called SOX 9 which switches on and off a variety of genes in brain testis such as Lhx9, Wt1, Dax1, Gata4, Dmtr1, Amh, Wnt4 and Dhh. These genes in turn switch on and off the production of hormones, which alter the development of the body and in turn effect the expression of other genes, while some of those genes could be sensitive to external experience, diet, social setting and culture. So we can see SRY as an archive, recipe, switch, interchangeable part or health giver of maleness.

FOXP2:

FoxP2, has recently been discovered on human chromosome 7 by Anthony Monaco and his colleagues at Oxford. Foxp2 is a gene whose job is to switch on other genes –a transcription factor and when it is bust, the person never develops full language. This gene is present in many animals like mice, monkeys, gorillas and chimpanzees and hence merely possessing the gene does not make speech possible. A mutant form of FOXP2 appeared in human race with changes that alter the protein product allowing the gene to be switched on in a certain part of the brain and there by does something new by connecting parts of the brain including the region between the temporal and frontal lobes called the Sylvian fissure which is responsible for motor control of the mouth and larynx.

The region in the brain responsible for both speech and gesture is called Broca's area. Language does not spring fully formed from the brain as it is learned from other language-speaking human beings. This capacity to learn is written into the human brain by genes that open and close a critical window during which learning takes place. If a child is not exposed to a lot of spoken language during the critical learning period, he or she will always struggle with speech even after having FoxP2 gene.

Role of HOX genes in human development. Hox genes specify developmental boundaries and determine cell fate during morphogenesis. Recently, two human syndromes, synpolydactyly (fusion of digits) and hand-foot-genital (limb malformations and urogenital defects ) were shown to result from mutations in HOX genes.
Genes responsible for human development

Hox genes:

Hox genes are switched on and off in different parts of the body at different times which results in different subtle effects, depending on where, when and how they are switched on. The switches that control this process are nothing but stretches of DNA upstream of genes and are known as promoters. Small changes in the promoter can have profound effects on the expression of a Hox gene. The source of the difference between the body shape of mice and chicken lies in the promoter attached to the HoxC8 gene that helps shape the thorax of the body. The promoter is a 200-letter paragraph of DNA, and in the two species it differs by just a handful of letters, but still alters the expression of the HoxC8 gene in the development of the embryo of chicken or a mouse which means the chicken makes thoracic vertebrae in a different part of the body than the mouse. In the python, HoxC8 is expressed right from the head and goes on being expressed for most of the body and hence they have one long thorax and ribs all down the body.The expression of a gene can be altered by adjusting the sequence of a promoter or adding a new one and to make changes in the body plan of animals, all you need do is switch the same ones on and off in different patterns.

The genome is not a blueprint for constructing a body. It is a recipe for baking a body. You could say the chicken embryo is marinated for a shorter time in the HoxC8 sauce than the mouse embryo is. Likewise, the development of a certain human behavior takes a certain time and occurs in a certain order, just as the cooking of a perfect souffle requires not just the right ingredients but also the right amount of cooking and the right order of events. As the hox story illustrates, DNA promoters express themselves in the fourth dimension: their timing is all.

The gene that made us human! Scientists decode a critical gene that may have led to the evolution of our big brains
ASPM gene:

The ASPM gene provides instructions for making a protein that is involved in cell division. This protein is found in cells and tissues throughout the body; however, it appears to be particularly important for the division of cells in the developing brain. Studies suggest that the ASPM protein helps maintain the orderly division of early brain cells called neural progenitor cells, which ultimately give rise to mature nerve cells (neurons). By promoting the division of neural progenitor cells during early brain development, the ASPM protein helps determine the total number of neurons and the overall size of the brain.

Geoffrey Woods discovered that 16th to 25th exons of this gene contains a characteristic motif which is usually 75 letters long and repeated over and over again. This sequence codes for amino acids isoleucine (abbreviation for I)and glutamine (abbreviation for Q). The repeats seem to be in proportion to the number of neurons. ASPM seems to be working by regulating the number of times the neuronal stem cells divide and there by decide the number of neurons.

Gene-environment interactions It is the complex interplay between our genetic makeup and our life experiences.
The reality is not digital:

If we follow a particular recipe, word for word, in a cookery book, what finally emerges from the oven is a cake. We cannot now break the cake into its component crumbs and say: this crumb corresponds to the first word in the recipe; this crumb corresponds to the second one in recipe.- Richard Dawkins.

The processes involved in behavioral and psychological development have certain metaphorical similarities to cooking. Both the raw ingredients and the manner in which they are combined are important. Timing also matters. In the cooking analogy, the raw ingredients represent the many genetic and environmental influences, while cooking represents the biological and psychological process of development. This metaphor however does not capture the alchemy of development in which two ingredients lead automatically to the production of a third and so on. The development of a certain human behavior takes a certain time and occurs in a certain order, just as cooking a perfect souffle requires not just the right ingredients, but also the right amount of cooking and the right order of events.

The interaction of both genes and environment affects the development of a person right from the time we are in the womb as genes interact with hormones in the environment to signal the start of a new developmental phase. Similarly, even if a person has inherited genes for taller than average height, the person may not grow to be as tall as is genetically possible if proper nutrition is not provided. It has been suggested that the key to understanding complex human behavior and diseases is to study genes, the environment, and the interactions between the two equally.

Both nature and nurture play an important role The free will and our personal experiences influence who we will be when we grow up.
It is Nature via Nurture

Donald Hebb is said to have answered a journalist's question of "which contributes more to personality-nature or nurture?" by asking in response, "Which contributes more to the area of a rectangle, its length or its width?". The area of a rectangle is the product of its length and width and hence depends on both of them.. Researchers on all sides of the nature vs nurture debate agree that the link between a gene and a behavior is not the same as cause and effect. While a gene may increase the likelihood that you'll behave in a particular way, your free will and your personal experiences influence who you will be when you grow up.

Environment influences the gene expression which is a long and circuitous path with many feedback loops before the code in genes is translated into physical features or behavioral traits. We are really asking ourselves the wrong question when we wonder if nature or nurture has a more powerful influence on who we are, as both of them play an important role. Our cells carry instructions for all the essential characteristics of humanity, but the process of developing from embryo to adult takes place in a physical and social environment that influences how these genes are expressed.

An example of circular causality - A flock of birds twisting and turning in unison Birds mostly fly along and it is impossible to find a linear sequence of cause and effect. It focuses on closed interdependencies.
Conclusion:

It is Circular causality of Nature via Nurture

According to neuroscientist Walter. J. Freeman, circular causality is an alternative to linear causality as linear causal chain cannot reconcile free will against universal determinism. Neurons in the brain get feedback from their recipients even before they finished sending messages and the response alters the message they send which in turn alters the response and so on. When thousands of neurons are involved in this process you will get sudden transitions from one pattern to another.

Consider a flock of birds twisting and turning in unison as they fly along and it is impossible to find a linear sequence of cause and effect. The cause itself (one of the birds turning to say left) seem to be influenced by the effect(the neighbor turning) as they move forward in time while influencing themselves. Similarly, if we take the example of getting up from bed, you will find it difficult to find the first cause of the actual moment of rising from bed, as it is buried in the circular process in which thoughts (like "I must get up"; "Let me sleep for some more time")and experiences (say alarm from the clock ) fed off each other.

Genes or environment ? When someone achieves greatness thanks to an innovation or other breakthrough, it is usually agreed that the individual has a high level of intelligence. Often, when exploring the background of the individual, the influences of nature versus nurture are questioned.
Genes are also steeped in circular causality

CREB genes that run learning and memory are the cause of behavior and they are also the consequence. Their promoters are designed to be switched on and off by events leading to transcription factors which are devices for switching on the promoters of other genes and those genes alter the synaptic connections between neurons; which in turn alters the neural circuitry, which in turn alters the expression of CREB genes by absorbing outside experience and so on round the circle. This is memory but other systems in the brain are also similarly circular as sense, memory and action influence each other through genetic mechanisms while translating experience into action. Free will is nothing but the sum and product of circular influences with varying network of neurons, immanent in a circular relationship between genes.

In Walter. J. Freeman's words "Each of us is a source of meaning, a wellspring for the flow of fresh constructions within our brains and bodies". There is no "me" inside my brain: there is only an ever changing set of brain states, a distillation of history, emotion, instinct, experience and the influence of other people and even chance. The more you discover genes that influence behavior, the more you find that they work through nurture and the more you find that we learn, the more you discover that learning works through genes. Genes extract information from the environment and they express themselves in response to the environment, though each of them individually has a well defined, predicable and deterministic messages to be carried out with due diligence.

References:

Biology: Science for Life; with Physiology; Colleen Belk, Virginia Borden Maier

Genetics: A Conceptual approach

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  • http://science.howstuffworks.com/life/evolution/nature-nurture.htm
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