Genetics study and studies on cognition and human brain are both highly debatable and as of yet quite inconclusive. At any given point of time a new theory would occur which would not simply negate, but completely annihilate those which came before this.
Though we are far from coming to a definitive and conclusive theory about human intelligence and cognition, it doesn’t do any harm in being familiar with all the developments.
The study we are talking about uses the premises of genetic studies, chromosomes in particular to postulate that a child inherits their intelligence from their mother. As we know, chromosomes are ribbon like tiny structures which are made up of protein and nucleic acid.
Their main function is to carry genetic information.
Everyone has one pair of chromosomes in each cell, the females have 2 X chromosomes whereas the males have one X and one Y chromosome. Another important concept that was used in this study is that of conditioned genes.
Conditioned genes are gender specific genes and depending on the gender have activated or deactivated traits. For instance, if a person inherits a particular trait from their mother, they paternal Gene is automatically deactivated in their cells and vice versa. It can be traced whether a specific trait is inherent from the mother or father by the tagging system of genetic material which uses tags of biochemical material.
Intelligence is one of the most highly conditioned genes and is influenced by the X chromosome. Mothers thereby have a higher influence on their children’s intelligence than fathers.
The lab experiment which proved this point used mice which were genetically modified to have either predominantly maternal genetic material or predominantly paternal genetic material. In the case of the former mice, the mice developed a comparatively smaller body but disproportionately larger brain and cranium size.
It was exactly the opposite case for the latter mice. Additionally it was found that absolutely no paternal genetic material was found in the cerebral cortex. The cerebral cortex is the part of the brain which is responsible for things like language, executive functioning, advanced thinking and logical planning.
This study is not the first one of its kind to say that mothers contribute much more to the cognitive abilities of the child, instead of both parents having an equal contribution. It goes back to 1984, and a University of Cambridge study which had similar findings.
If not seen solely at a genetic level, it becomes even clearer how mothers might impact their progeny more than fathers. Mothers are the primary caregivers and responsible for the nurturing and nourishment of their child, two things which have a direct influence on a child’s brain development. Also, the child learns to look at the world through his mother’s eyes. The bond between a mother and child provides necessary context to the latter to later perceive and interpret the world.