Intelligence is inherited from the mother, reveals science

The intelligence It is one of the most recurring themes in Psychology and Mind. Besides having a whole section dedicated to various monographs, research and theories on intelligence, today we echo a particularly interesting issue.

Intelligence: is it inherited… from the mother?

People who are lucky enough to be smarter than average should start thanking one other person in particular: their mothers. And it is that, according to several investigations, it seems that mothers are the ones who transmit most of the genetic load related to cognitive abilities.

This would refute many of the gender prejudices that are still deeply rooted in our societies and that have cruelly accompanied women in particular for centuries. According to this information, the intelligence of the parent would not be a strong factor when it comes to predicting the intelligence of the children.

Conditioned genes, the key to everything

The scientific basis of this matter resides precisely in the existence of "conditioned genes". These genetic components, as described by biologists who have studied them in depth, behave differently depending on whether they originate from a male or female body.

Apparently, these genes contain something like a biochemical tag that provides information about where they came from, and that even reveals whether these genes will be active or not in the cells of the child. Specifically, some conditioned genes are only activated if they come from the mother. In the event that this same gene is inherited through the father, it is not activated. As might be expected, there are other genes that work the other way: that is, they are only activated if they come from the father.

X chromosome, essential in the development of cognitive potential

It is well known that intelligence is inherited from parents to children, but until recently there was no evidence that this capacity was due to a greater extent from one of the two parents. The different studies that have revealed that children have a greater probability of inheriting the intelligence of the mother suggest that genes related to cognitive abilities are located in it X chromosome.

In fact, the data that support this thesis come from afar. In 1984, a study at the University of Cambridge already detected the trend. The team of researchers analyzed certain biochemical and genetic components of the brain, and came to the conclusion that the mother's genes provide more information for the development of brain structures associated with thinking and mental operations.

To arrive at this surprising finding, the researchers worked with embryos of mice modified to reproduce only the genes of the mother or those of the father. However, when the scientists transferred the embryos to the uterus of a female mouse so that they could continue to develop, they died.

In this way, the researchers realized that there are conditioned genes that only activate when they are inherited through the mother, and that are essential for the development and survival of the embryo. Something different happened with embryos that were genetic copies of the parents: their genes were crucial for the growth of placental tissues. They also died.

The hypothesis was clear: if those particular genes were so highly essential for the development (and survival) of the embryo, it would be reasonable to think that they would be genes with great responsibilities in the organic functioning of animals and humans, and perhaps they could have a strong relationship with certain functions cerebral. A hypothesis that, after successive studies isolating variables, was validated.

Mice with amazingly big heads

Mice with a higher proportion of maternal genes had abnormally large brains, yet their bodies were very small. In contrast, the mice with paternal genes had a tiny head and a hyperdeveloped body.

As scientists began to detect which genes came from the mother and which from the father, in turn identified several cells that only contained maternal or paternal genes in different brain areas that govern different functions and cognitive processes, such as intelligence or memory.

The scientists did not find any paternal cells in the cerebral cortex, where the structures that give us life are located. allow complex cognitive functions, such as intelligence, decision-making, language and others skills.

New research and evidence

Over the years, the scientific community has been reviewing this curious genetic phenomenon. In fact, one of the most renowned researchers in the field of intelligence, Robert Lehrke, revealed that most of the intellectual capacity of newborns is generated on the X chromosome. He was even able to show that women are twice as likely to inherit traits linked to intelligence, by having the same 'X' chromosome twice.

A few months ago, another study from the German University of Ulm discovered that the genetic material involved in brain damage is closely linked to the X chromosome. In addition, they pointed out that one of the evidences of this is the fact that mental and intellectual disabilities are 30% more frequent in men.

IQ predictor

All of the above studies are very interesting and provide specific clues to the relationship between the mother's genes and intelligence. However, one of the most revealing studies is the longitudinal analysis carried out in the mEdical Research Council Social and Public Health Sciences Unit from USA.

Over a long period of time, 12,000 young people between the ages of 13 and 22 were interviewed annually. Analyzing different variables about individuals, such as skin color or sociocultural and economic level, they discovered that the indicator that best predicted the intelligence of each subject was the I.C. from his mother.

Beyond genetics

But not only genetics gives us data on this issue. There are other investigations that show that the mother plays a fundamental role in the intellectual and cognitive development of her children, through daily stimuli. Several studies suggest that the attachment, that bond of pristine trust with the mother, is closely related to future intelligence.

Attachment and its importance for the development of intelligence

Several investigations at the University of North Carolina, among many others, found that children who successfully develop a secure attachment to their mothers are capable of more complex pretend play. In addition, they are more constant and have a higher tolerance for frustration.

It seems that secure attachment offers the foundations for children to grow trusting in their possibilities, facing challenges to make an effort and solve their day-to-day problems. It is also noteworthy that the mothers who provide this secure attachment are also the ones who stimulate their children more and better so that they can advance in their cognitive development.

What percentage of intelligence is inherited?

But is intelligence really inherited? In what proportion is it so? It is often said that between 45 and 55% of intelligence is written in the genes. This makes us understand that there is also a significant part, approximately half, that develops if family, social and personal conditions are good.

And it is worth remembering that intelligence is nothing other than the ability that human beings have to solve problems. There is no specific area of ​​the brain in charge of solving problems, rather it is our entire brain in its set that works globally to address any task that requires an effort of our abilities cognitive. Also, to make matters worse, not only do we use rational thought for these purposes, but also the heuristic thinking, intuition and emotions, which are usually more related to the genetic inheritance of the father.

Stimulate the intelligence of the child

Do not pay excessive attention to the I.C. of a son. Intelligence is an extremely complex construct, which develops if the child's mind is stimulated conveniently, with challenges and tasks that, little by little, will force you to climb in your stages of development cognitive.

As parents, we must be capable of understanding that we can contribute a lot to our children's maturing and they develop more complex cognitive abilities, and this must be done, let's not forget, attending to the emotional and playful needs of the little ones in the house. Everything helps.

It may interest you: "5 tips to nurture your child with emotional intelligence"

Bibliographic references:

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• Keverne, E. B.; Surani, M. TO. et. Al. (2004) Coadaptation in mother and infant regulated by a paternally expressed imprinted gene. Proc Biol Sci.; 271(1545): 1303–1309.
• Matas, L.; Arend, R. TO. & Sroufe, L. TO. (1978) Continuity of adaptation in the second year The relationship between quahty of attachment and later competition. child development; 49: 547-556.
• Prieto, M.D. and Arnáiz, P. (1989). A cognitive approach to the assessment of intelligence abilities in Special Education. In M.P. Covers, (coord.). The evaluation of educational programs. Madrid: Spanish School.
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