4.b) Heredity vs. environment

Philosophy of History and evolution of intelligence. The influence of environment and heredity in intelligence. Arguments of the theory of natural selection against the role of genetics.

The following points have been grouped together because it is not easy to separate the arguments against what is being stated and current difficulties; if both things are not due, to a great extent, to the lack of a true interest in the subject, both on a personal and political level for philosophical or sociological reasons.

We will site the following paragraph by way of 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; this means referring to 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 subjective attitude impregnated with a kind-hearted egalitarianism and a so-called idealism.

I do not want to say that this idea is necessarily mistaken but rather that its arguments are not scientific and are slightly contradictory. It seems that there is a certain philosophical correlation between this idealism and egalitarianism and what we could call historical materialism, or if you prefer, modern materialism.

To me, it seems obvious that human intelligence has developed a lot in the last thousands of years. In the same way, the great difference in intelligence between different individuals is easily observable.

This could perhaps be much greater than what is politically desirable, and for this, is denied in advance to try to obtain certain measurements of intelligence that are slightly less relative than the current intelligence quotients. The curious results of certain studies are deliberately hidden or silenced while publicity is given to other studies that we could call 'substitutes.'

At the same time, the connotations of the Nazi idea that intelligence can be hereditary is often indicated. The danger of this way of thinking is that if we end up demonstrating that intelligence is like this, it would be proving that the Nazis' ideology is correct. I would say that it is clearly better not to mix politics with science if you want to maintain a scientific point of view.

As this point does not take us anywhere, we will finalize it with a quote from Galileo Galilei's personal 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

It is generally accepted that a certain degree of intelligence has to be hereditary; this is demonstrated by the visible difference of intelligence between different species of animals.

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 a highly superior intelligence.

Saying that the evolution of animal intelligence has been produced by random mutations of DNA chains is hardly convincing (it sounds like science-fiction) due to the evolutionary lottery that it would be implying. This consequence is another one of the great difficulties in the fundamentally hereditary nature of intelligence; it means having to directly face 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 out full potential, etc. Although the only thing this achieves, if you think about it, is augment the problem. At some point, intelligence should increase, and logically, it is even more improbable that this big increase would be produced by random mutations. This does not however prove to be problematic; everything eases over time.

Also, the problem would change dimensions because, upon rejecting the theory of mutations, an alternative theory of evolution would have to be found that would provide a coherent model.



4.b.3) Environment and intelligence

Presumably the environmental conditions that could affect the development of intelligence will be related to a greater and lesser extent to the intelligence quotient of the people who share a living space, and other variables likewise related.

These interrelations could partially hinder or hide the true origin or cause of the capacities studied in multiple regression studies.

The need for certain 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 not doubt that intellectual potential will be seriously affected.

However, in the absence of these serious limitations, the development of the intellectual potential, in my opinion, will be slightly less than its maximum. In other words, the wide majority of the population in a developed country or a country without serious food shortages will find itself in environmental conditions superior to those corresponding at point X1 of the graph.

The GTCEL section includes a different focus to what is generally said as far as the environmental influence on the intelligence. According to this, intelligence and all genetic traits are developed throughout individuals' lives and these improvements are also incorporated into genetic information.

The two stances can be clarified 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, others as chickens, etc. On the contrary, the GTCEL would state that the birds are born with a determined structure and that, of course, normal growth takes place in practically all of them; they perfect the art of flying during their development and the children will maintain this structure.

Intellectual power
Intellectual power

Consequently, both stances are not that contradictory if we think of them as existing in different scales of the analysis of intelligence. I hope that the results of the EDI Study will allow some approximation between both perspectives.

4.b.4) Training and IQ testing

It is worth pointing out that an intelligence test is designed to measure certain capacities that do not increase easily when the test is repeated. 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 normal for individuals in society to be intelligence professionals in the same sense as in sports; they seem to be paid less. On the contrary, 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, I think that a person's speed in a 100-metre flat race is fundamentally determined by inheritance, that is, by the physical constitution of each individual.

Sometimes I ask myself: 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 tobacco, alcohol, and some traffic accidents would have a similar effect in both cases.

More information on this can be found in the section on the inheritance character of intelligence model which is included in the online book The EDI Study.