Mother’s genes go to the cerebral cortex, those of the father goes to the limbic system.
Everybody believes that kids’ intelligence has a hereditary component. And most of the people claim that it depends on both the father and mother. However, studies revealed that children are most likely to inherit intelligence from their mother because genes that carry intelligence come from chromosome X.
A study that was conducted in 1984 at the University of Cambridge has proven that the maternal genes contribute most to the development of the though centers of the brain. In their experiment, they created embryos of rats that only had the genes of father and mother, but they failed when they died as they are about to be transferred to the adult rat. After a few more tries, they discovered that embryos with an extra dose of maternal genes developed a bigger head and brain, but had little bodies. As for those with an extra dose of paternal genes, they had small brains but bigger bodies. As they looked closely, they identified cells that contain only maternal or paternal genes in six different parts of the brain that control different cognitive functions, from eating habits down to memory.
During the first days of embryonic development, cells can appear anywhere in the brain, but as the embryo matures, cells that had paternal genes accrue in the emotional centers of the brain: hypothalamus, amygdale, preoptic area and the septum. These are parts of the limbic system that is responsible for ensuring survival and is involved in functions such as sex, food and aggression. However, these are the cells that the researchers haven’t found in the cerebral cortex, a part of the brain where cognitive functions such as intelligence, thought, language, and planning develops.
Scientists didn’t stop investigating, Robert Lehrke revealed that most of a child’s intelligence depends on the X chromosome because women have two of them; they are twice as likely to inherit characteristics that are related to intelligence.
Genetics is not the only factor.
Kids inherit their intelligence from their mother not just because of the genetic make-up that has been proven way back 1980’s. It is revealed that the mother plays an important role in the intellectual development of children whether it may be physical or emotional contact. Some studies even suggest that a secure bond is tied to intelligence. The researchers from the University of Minnesota found that children who developed a strong attachment to their mothers have the capacity of playing complex games at the age of 2, they are more persistent and show less frustration while playing.
The reason behind it is because the children feel the strong bond, they feel secure and confident to explore the world and solve problems without losing heart. Furthermore, these kinds of mothers tend to give their children a higher level of support by helping them stimulate their potential.
Yes, kids may inherit their intelligence from their moms but it doesn’t mean that their relationship with their father shouldn’t be developed. Both parents are still important and should go hand-in-hand in helping the child reach his/her full potential. It is estimated that between 40-60% of intelligence is hereditary. It means that the remaining percentage depends on the environment and stimulation.
A child who has a high IQ must be nurtured, thus their intelligence must be stimulated throughout life with new challenges. Otherwise, intelligence would be nothing.
Sources: Luby, J. L. et. Al. (2012) Maternal support in early childhood predicts larger hippocampal volumes at school age. Journal of Proceedings of the National Academy of Sciences; 109(8): 2854–2859. Gécz, J. & Mulley, J. (2000) Genes for Cognitive Function: Developments on the X. Genome Res; 10: 157-163. Keverne, E. B.; Surani, M. A. et. Al. (1996) Genomic imprinting and the differential roles of parental genomes in brain development. Brain Res Dev Brain Res; 92(1): 91-100. Keverne, E. B. et. Al. (1996) Primate brain evolution, genetic and functional considerations. Proc. R. Soc. Lond. (Biol); 264: 1-8. Allen, N. D. et. Al. (1995) Distribution of parthenogenetic cells in the mouse brain and their influence on brain development and behavior. Proc Natl Acad Sci U S A. ; 92(23): 10782–10786.