4.b) Heredity vs. environment
The following points are in specific groups because it is not easy to separate the arguments in this subject. It seems there is a lack of interest in the subject, both on a personal and political level for philosophical or sociological reasons because either there is no evidence or it is denied.
We can cite the following paragraph as an example, which contains a study on inheritance in continuous variables:
Given that there is currently not a definition or an objective measurement of intelligence, it is not reliable to use the methods of quantitative genetics to research the heritability of this characteristic.
Many of the following points have this common denominator.
4.b.1. Modern materialism
A typical stance refers to the environmental influence on the development of human intelligence; it mentions both the small variations that have existed both between individuals and occurrences in the last thousand years of the human species. Furthermore, they are minimum variances, if we compare them to the differences between the intelligence of diverse species.
This vision of reality is without a doubt, the greatest obstacle for the acceptance of our postulates; it deals with a personal attitude impregnated with a kind-hearted egalitarianism and a so-called idealism.
We do not want to say this idea is necessarily mistaken but rather that its arguments are not scientific and are slightly contradictory. There is a philosophical correlation between this idealism and egalitarianism and the famous historical materialism.
We believe it is evident that human intelligence has developed a lot in the last thousands of years. Also, the significant difference in intelligence between individuals is readily observable.
It could perhaps be much higher than what is politically desirable or people, in general, would like to hear; therefore, it is denied in advance to obtain specific measurements of intelligence that are slightly less relative than the current intelligence quotients. Whatever the results of the studies are, some of them will have a more significant presence in social media.
At the same time, the connotations of a Nazi author when supporting the idea of intelligence being hereditary spreads out. It would be better not to mix politics with science in order to maintain a healthy scientific point of view.
As this point does not take us anywhere, we will finalize it with a quote from Galileo Galilei's point of view: Although there is a vast difference between man and other animals, we could say that this abyss is no deeper than what separates some men from others. He had his reasons!
4.b.2. Theory of natural selection
A certain degree of intelligence has to be hereditary; the visible difference of intelligence between different species of animals makes it palpable.
If genetic intelligence were very similar for all members of one species, it would be very complicated to explain the appearance of new species with highly superior intelligence.
The evolution of animal intelligence produced by random mutations of DNA chains is hardly convincing; it would imply that a personal computer could come from random mutations in molecules in a planet. This argument is another one of the great difficulties in the hereditary nature of intelligence; it goes against the evolutionary theory of natural selection.
Along these lines, ideas have come up that human intelligence has not changed in the last thousands of years, that we do not use our full potential. Although, the only thing these ideas achieve is to augment the problem. At some point, intelligence should increase, and logically, it is even more improbable a vast and fast increase will occur by random mutations. However, it is not proving to be problematic; everything eases over time.
Also, the problem would change dimensions because, upon rejecting the theory of mutations, we would need an alternative theory of evolution and the theory of Lamarck was not enough at the time.
4.b.3. Environment and intelligence
Presumably, the environmental conditions affecting the development of intelligence should relate to the intelligence quotient of the people sharing a living space and other variables.
These interrelations could partially hinder or hide the true origin or cause of the capacities studied in multiple regression studies.
The need for specific environmental conditions for human development is another aspect of the environment and intelligence issue. In very adverse conditions such as the lack of oxygen during birth, children rose by wolves, alcoholism during pregnancy, meningitis, or other extreme situations, there is no doubt that intellectual potential will be severely affected.
Nonetheless, in the absence of these limitations, the development of the intellectual potential will be slightly less than its maximum. In other words, the vast majority of the population in a developed country or a country without grave food shortages will find itself in environmental conditions superior to those corresponding at point X1 of the graph.
The Conditional Evolution of Life section includes a different focus to what is generally said as far as the environmental influence on the intelligence. IQ and genetic traits mainly develope throughout individuals' lives, and the improvements go to the offspring.
We could see the two stances with a slightly radical metaphor: those in favor of the environmental influence on intelligence would say that birds are all born with the potential to fly like an eagle, but some remain as ostriches and others as chickens. On the contrary, the Conditional Evolution of Life would state that the birds are born with a particular structure and that, of course, normal growth takes place in practically all of them; they perfect the art of flying during their development, and their offspring will maintain the specific structure of their progenitors.
Consequently, both postures are not so contradictory if we think of them as existing in different scales of the analysis of intelligence. The results of the EDI Study allow some approximation between both perspectives.
4.b.4. Training and IQ testing
An intelligence test is designed to measure specific capacities that do not increase easily when doing the test several times. Of course, if we dedicated ourselves intensely to the preparation of these tests, our results would be higher; but in this case, it would not even be a permanent quality.
A comparison often made to justify the environmental effect on intelligence is how physical exercise changes athletes' performance.
In these instances, we all unconsciously think about top-ranking athletes or sports professionals. First of all, it is not typical for individuals in society to be intelligence professionals in the same sense as in sports; they seem to earn less. Nevertheless, a large part of the population presumably uses intelligence daily, even though it sometimes may not seem so for some people.
Secondly, aside from exceptions of sports professionals and people who do not exercise at all, We think that inheritance fundamentally determines a person's speed in a 100-meter flat race, that is, by the physical constitution of each. Of course, unless there is terrible nutrition, which in the case of intelligence it is not very probable.
Sometimes we ask ourselves: is there a scientific base to say that intelligence and effort or performance made in a marathon behave the same as for the development of a person's potential? Are there coefficients of marathon potential with normal distribution in the population? Is the conventional male/female equality maintained in these variables? Can the difference in physical strength be justified bearing in mind educational disparities at an early age without straying away from the scientific method?
On the other hand, maybe alcohol, and some traffic accidents would have a similar effect in both cases.
More information on this subject is in the section on the inheritance character of intelligence model of the online book The EDI Study.