Neuroscientists have determined that the intelligence a person inherits at birth, increases during the growth to maturity. In this article I examine how this phenomenon emerged. It turns out to be related to a decrease in skull growth over the last 400,000 years of human development. Here it is assumed that in the final stage of the creation of mankind the increase of intelligence was more and more the result of an increase in mutual wiring between the neurons instead of an actual increase in neurons. This article is a continuation of article 1 with the title WITHOUT HANDS NO INTELLIGENCE.
In a previous article a theory F about intelligence was launched.
The basis of this theory is that an animal with intelligence is able to invent new manipulations that are advantageous to him.
That intelligence was the "engine" that established the evolution of a squirrel-like animal, living 60 Ma ago,
to a chimpanzee 54 Ma later (Ma = million années).
That article also describes the concept of arsenal (= total number of manipulations which the animal possesses)
and that also this number is measurement for his intelligence (the so called Intelligence Number = IN).
The behaviour of the Chimp was used to demonstrate the operation of this new theory,
because it is an animal whose behavior in the wild has been studied very thoroughly.
The previous article actually describes the beginning of the evolution from animals to humans.
This article discusses the end of that evolution because that is when a new kind of a intelligence growth took place.
It is first necessary to explain something. In the book you will read that in the final stage of the creation of mankind, there were other accomplishments, in addition to the manipulations, that were to result in the growth of the intelligence. An accomplishment in that late stage is for example: 2x3=6 as a memory storage to be able to calculate or the law of Archimedes also as memory storage in order to design floating devices.
That means, that with coming up with these accomplishments, the arsenal also gets larger and thus his IN grows. A manipulation is also an "accomplishment". Now you know what is meant if you come across this word.
This article is derived from a book by the same author. Title: zonder Handen geen Intelligentie (without Hands no Intelligence), In that book, you will find the citations and bibliography. The objective of this article is to show the lines along which the mind went for building theory F.
After hominids the evolutionary growth of the intelligence virtually came to a halt.
In a previous article I described that the ancestors of the chimpanzee came to an evolutionary growth
of their intelligence thanks to their hands. The growth continued through to the successors of the chimpanzee.
These successors were confronted with a profound change in their environment or habitat.
Somewhere in East Africa a crack in the Earth's crust arose 10 Ma years ago due to Earth plates drifting apart. That crack was filled up with magma. At the same time high mountains were formed along the edges of the crack. A narrow area running from North to South arose, called a rift (valley). Because of the mountains the humid winds of the Indian Ocean could not penetrate through to the rift valley anymore. Due to the local climate change the rift valley evolved from a rainforest to a savannah with only sporadic arboreal vegetation. The chimps living there were forced to leave the trees and start an existence on the ground. The chimpanzees living outside that strip, which is a vast area south of the Sahara, remained tree dwellers to the present day. It is more correct to speak of a common ancestor of mankind and the chimpanzee to whom this occurred. This common ancestor, which very much resembled the Chimp, ended up on that spot in a new habitat.
He learned to walk on two legs and how to use his hands to make cutting tools from a boulder. He became more capable because he developed an opposable thumb. For millions of years he continually developed manipulations, his arsenal became bigger still and his Intelligence Number IN grew steadily. He became more and more hominid.
So, approximately 0,2 Ma years ago, Homo sapiens arose, still in East Africa. He was almost our equal in appearance, but not yet in intelligence and he could already communicate pretty well with his peers using spoken language.
But he also was confronted with two effects that restrained the evolutionary growth of intelligence.
Effect 1 arose by the invention of new manipulations in different minds, which were no longer copied by peers.
Up to a certain point in the evolution a new manipulation arose in one mind
and the community took advantage of this by imitating and demonstrating it to the offspring
(it is to be understood that a following new manipulation arose in another mind and generations later).
Hence the arsenal stayed equal in composition for everyone. But gradually some of the new manipulations were not copied any more by the community. Arsenals with different compositions arose. That was a result of specialization: for some people were skillful at making stone tools, other at making baskets. But everyone took advantage of that specialization by exchanging goods or services, without adding the new manipulations to their own arsenal.
That meant that the individual arsenals grew slower in size and that again meant that the maximum number of manipulations that were applicable for the intelligence obtained at that moment, was reached later. The moment that the next step to enhancing intelligence occurred (by a mutation) therefore also moved up further in time. The resulting effect of all of this was that intelligence growth began to level off.
As said the advantages came about by exchanging goods and services. But this could only happen if negotiation was possible and that requires language and a notion of numbers.
Looking at the development of language, which started about 1 Ma ago, it is likely that these capabilities had reached a sufficient level to negotiate about commerce around 0.2 Ma ago. So that is when the slowdown of the growth to higher intelligence started.
Effect 2 was the growing size of the population.
Starting from 0.043 Ma, the time that Homo sapiens arrived in Europe, the population there grew rapidly.
Distribution of a new trait in a population occurs faster when that population is smaller in size.
Conversely, the opposite happens in a large population. So also for this reason the growth of intelligence decreased.
The two effects caused a decrease in the evolutionary growth of the intelligence.
So we face the mystery that a population in its last phase of development barely grew in hereditary intelligence. While we know that it is precisely at that stage a society was formed, characterized by techniques with an immense diversity. A variety that indicates a very high intelligence.
Now read how this came about.
We only inherit part of the intelligence that we possess at adulthood
Scientists have determined that part of our intelligence arises during our youth.
Thus the intelligence we have with our birth, increases further during our growth to adulthood.
Here we talk of "a part of our intelligence", so there must be a measurable intelligence in terms of size or ability. We all know the IQ intelligence quotient to help measure the size of a person's intelligence. However that does not measure an absolute size of intelligence but only how one’s intelligence relates to the average intelligence of the population in which one lives.
However, it appears from analyses of many IQ- results, that it is possible to determine the ratio between the inheritable- and the growth-intelligence without involving absolute values. So one could still determine the law mentioned above.
In the previous article it is explained that intelligence as defined by theory F is very plausible and that therefore this increase is also valid for this theory. So far intelligence is mentioned as a congenital feature and it appears now to be only a part of the story. That phenomenon started sometime in the past and has slowly grown to the current size, in nature nothing ever arises all of a sudden. Now suppose that there was a mutation in hereditary characteristics by which a property arose that caused the intelligence to increase every time that a new accomplishment was invented and was added to the arsenal.
So the growth in intelligence became independent of an evolutionary development. Although it still remained dependent on the ability to achieve a new accomplishment. This means that devices must also be available to achieve the new accomplishment. Remember: a horse with a human brain cannot accomplish the accomplishments devised by human-intelligence because it misses the devices for that.
An innate property was formed that meant the same for any mortal: namely growth of intelligence every time that a new accomplishment was added. That is exactly what happens during the growth to adulthood. A baby starts with an empty arsenal and spends his youth taking over arsenals with accomplishments from his teachers (parents, school teachers etc.). In the new situation this growth also depends on a new accomplishment. That remains the guiding principle, it is part of the intelligence theory F.
The thus formed intelligence is called growth-intelligence , a new way of intelligence growth besides the hereditable-intelligence. The two kinds of intelligence are exactly the same to each other when it comes to the functioning inventing new accomplishments. They differ only by the way of genesis. It is assumed that this mutation occurred about 0.4 Ma ago and that from that moment on, this mode of intelligence growth next to hereditable-intelligence gradually grew. The growth-intelligence completed virtually mankind.
Now we still have to discuss those 0.4 Ma. The following reasoning leads to this date: a brain function is based on a specific interaction between brain cells, the neurons. This connection is achieved by the axons and branches (see figure).