The question as to whether nature or nurture, heredity or environment, specificity or plasticity, is more important in the shaping of organisms, or more specifically humans, is misleading. The basic premise that one or the other is more important is fallacious. Yet, the nature-nurture problem is not meaningless.
All human variation is always the result of as much the environment as of the hereditary constitution. Genotype and environment are equally important, both are indispensable. Where exists the organism without genes? Where exists the organism without an environment? Such traits as skin pigmentation, health, intelligence, and temperament, are all determined by the interaction of genotypes with their environments. Therefore there arises the question as to the respective roles of genotype and environment. To what extent, it is thus posed, are differences due to genotypic or to environmental causes? What part of the observed variances in a given character or trait in a given population is due to diversity of genotypes, or diversity of environments? This apparent dichotomy of the hereditary and environmental factors is a false one. This is because any trait is both genetic and environmental.
The nature-nurture problem has to be stated correctly. The answer depends on which differences, features, characters or traits, are being considered. For example, the inheritance of blood groups or intelligence. Two aspects then become obvious – the contribution of genetic and environmental variables may be quite different for different characteristics. As stated previously, examples can readily be seen in comparison of blood groups and intelligence. Genetic determinants for blood, but environmental for a trait such as language, and in all probability an interactive answer for a character such as intelligence. Again, we have to be aware of the cultural determinants as well as the complexities of such a phenomenon as multifactorial inheritance. The relative weights of genetic and environmental variables are not constant, they change in both space and time. We cannot assume in humans a population fixity of characters.
Most human differences, like many animal differences (individual variations within species) lie between the extremes of rigid genetic and purely environmental causation. It is therefore extremely difficult to estimate the relative magnitudes of the genetic and environmental contributions to traits observed in organisms. The environment is responsible for a part of the observed variation in stature. If, for example, the environment became homogenous people will differ in stature because of gene variation. In antithesis, if the situation was one for genetic homogeneity we could state that environmental difference will account for a relative part of the variance in stature. This problem has been encountered in the studies of human development, earlier maturation, and increased stature in children. What is the relation of genes and environment to increased stature, and earlier onset of menarche? What is the role of genetic potential and better nutrition?
There can be no single solution to the nature-nurture problem because objectivity necessitates that the matter must be studies separately for each trait. Results will then have validity for the population studied only in context of their time and place. Without undue and unscientific extrapolation from one group to another.
The nature-nurture dispute has quite a long history. John Locke (1632-1704) put forward the tabula rasa theory in so far as he regarded the mind of the new born infant to be a blank page. A modern exponent of the view is M. F. Ashley Montagu and the theory of the innate good of man. The tabula rasa notion was the product of the intellectual progress of the Age of Enlightenment, with its concept of all men born equal. However, the principles of egalitarianism and tabula rasa refer entirely to different matters. Equality is a social concept, an economic relationship, or an ethical or juridical tenet. Tabula rasa in terms of brain development is applicable to both aristocratic and proletarian cerebri, as well as having undertones of conflict with a priori considerations.
The 19th century is often termed the Age of Science, and one protagonist in the arena of nature-nurture debates of the time was Count Gobineau, an historian cum biologists in France. Gobineau published, in 1855, a work entitles Essay of the Inequality of Human Races. The basic argument put forward by Gobineau was that all the achievements of humankind must be credited to small, creative minorities, whose natural superiority gave them credence to subdue, conquer, and enslave the more numerous and inferior common herd. In essentials his essay attempted to give scientific justification to both race and class prejudice. In England Francis Galton (1822-1911) declared that ‘…the instincts and faculties of different men and races differ in a variety of ways almost as profoundly as those of animals in different cages in the zoo.” Founder of the eugenical movement, Galton was an outstanding biologist and firm believer in the supremacy of heredity over environment, of nature over nurture.
White, in 1949, took the biological standpoint that the differences among men were insignificant as compared to their similarities. His view was that in reference to human behaviour the evidence pointed to the insignificance of biological factors as compared to cultural factors. Hence, in no way, is variation in human behaviour due to a variation of a biological nature. Mankind was thus a constant, it being culture that was, and is, the variable. The view is environmentalist whereas C. D. Darlington is an emphatic hereditarian. In 1953 (The Facts of Life, London) he expounded the view that “…owing to inborn characters we live in different worlds, viewing it through different eyes.”, and furthermore “…the materials of heredity contained in the chromosomes are the solid-stuff which ultimately determines the course of history.” Since this pronunciation Darlington has in fact made his attempt to rewrite history in terms of genetics (Darlington (1969), The Evolution of Man and Society).
It is interesting to note that in 1949 a survey compared the socio-political views of 24 psychologists, biologists, and sociologists. Of 12 who were typed as liberals and radicals, 11 were of environmental inclination. The 12 classified as conservative had among them 11 hereditarians. This is an interesting point to remember when one sees the modern nature-nurture debate with regards to black and white intelligence, that the whole matte is fired also by political stance as well as scientific viewpoint. It is disturbing that nature-nurture correlates with left and right or right and left.
All observed differences in phenotype may be caused either by genetic or environmental variables, by interaction of the two, and thus not necessarily by one or the other. Analogues are not enough, especially as variations in some traits appear entirely genetic, others entirely environmental, and still others part genes, part culture. What has to be established are the relative magnitudes of all the variant components such as trait, population, and time.
For consideration of a specific issue the hot debate about intelligence still boils. When trying to establish an IQ level we are faced with the problem of differentiating the relative contributions of heredity and environment. The problem with psychometry or intelligence testing is its point of departure. It is this point that determines the whole direction of, and nature of, investigations and interpretations. What is thus open to question is the assumption that human mental powers depend upon interaction of heredity and environment. This dates back to the biological
origins of psychometry in the late 19th century. Such a problem, as psychometry is, delimits findings because it can only postulate that either heredity or environment is the chief factors. Heredity becomes speculation clouded with statistics, and environment becomes a vague general category, confusing factors that are qualitatively different – the social and the natural. An alternative is thus – the interaction of both. The initial hereditarian assumption rules out the role of education in the social environment and human activity. It is therefore necessary to eliminate preconceived ideas about the nature of human development being equated with animal development. What has to be understood are the specific qualities of human learning and the role of education in the formation of social humankind.
The consolidation and transmission of human achievements takes place in a particular form. This is the external and exoteric – in so far as it is popular, ordinary, and is intelligibly understandable. This is a new form of phylogenetic experience, it becomes socio-political. This has arisen because the human form of specific activity is social, is productive. This is in contrast to the development of animal species, whose achievements are consolidated in the form of changes in their biological organisation, in their genetic and brain development. Human development is also consolidated by material and cultural objects, and in ideal phenomena such as language, and the science that they create. The key to human development on this level is not heredity but education.
In the course of their history humans are governed by social laws which are developed with, and by, higher characteristics of mind. Thousands of years have produced more than the millions of biological evolution. Achievements of mental development have been accumulated and transmitted from generation to generation. The historical process is rapid, accelerating, quite out of relation to the much slower tempo of the biological fixation of experience in animals. The environment and heredity cannot be reduced to a set of quantitative variables, a series of mechanical models or paradigms. Avoided has to be the pitfall of quantification for the sake of quantification which can only lead to a short-sighted empiricism or mere operational exercises. Historical reality and genetic constitution are complex, their truths being unlikely to be discovered by any dogmatic scientism – the function of which would not be to discover truth but to justify inevitabilities of the status quo.
Human Sciences (1971-1974).