Experts point out that the extra X chromosome of the mother is responsible for this and elaborate on how non-genetic factors too help a child to reach his/her full potential
It is quite common to hear parents swell with pride when their progeny has achieved something great and announce to all who would listen "She's MY daughter/son, after all!" More often than not, the parents can't reach a consensus as to who deserves credit for the child's genius. If you have ever wondered which parent you should thank for your intelligence, now you have a definite answer — your mother. Going by the theory of scientist Robert Lehrke, author of 'Sex Linkage Of Intelligence', research reveals that children get their intelligence from their mother. A child gets its natural intellectual ability from the mother and not from the father.
This is because, according to Lehrke, most of a child’s intelligence depends on the X chromosome, and since women carry two of these chromosomes (XX), children are more likely to inherit it from the mother. Men have only one X chromosome (XY), so the chances of kids taking on intelligence from their mother are doubled. An important thing to note here is that around 40-60 percent of intelligence is inherited, while the rest depends on stimulation, environment, and personal traits.
Researchers from the University of Ulm in Germany who were studying genes involved in brain damage revealed facts related to the X chromosome. Their study says that this chromosome has cognitive abilities. It is no coincidence, then, that mental disability is 30% more common among males.
The entire debate around women passing on the IQ chromosome to the kids was triggered in 1984, when a study on similar lines was conducted by experts at the University of Cambridge. The co-evolution of the brain and the conditioning of the genome were studied, leading scientists to conclude that maternal genes contribute most to the development of the thought centers in the brain. The studies were conducted on embryos of rats that had only genes of the mother or the father.
Another analysis by the Medical Research Council Social and Public Health Sciences in Glasgow, Scotland, which involved 12,686 young people (age 14 to 22), found that the best bet for their intelligence was on the mother. They were interviewed every year from 1994, taking into account several factors like skin-color, education, and socio-economic status.
Some studies also found out that mothers play an important role when it comes to intelligence in a non-genetic way. A strong bond between the mum and the child is directly tied to intelligence. The security that a mother provides is linked to the confidence and strength required to face and explore the world and the smartness to solve problems. A deeper bond is directly related to a child reaching his full potential. Traditionally, mothers tend to spend more time with the child, since they are the primary caregivers; hence, it is only natural for children to form a richer bond with the mother.
Researchers from the University of Washington scrutinized the way mothers relate with their children and found that those who were emotionally supportive and fulfilled their child’s emotional and intellectual needs, had a surprising result. They conducted a study for 7 years and found that the hippocampus (responsible for storing memories) of these kids at the age 13 was 10 percent greater than that of the kids whose mothers were emotionally not so involved.
Of course, this is not to discount the role that a father plays in a child's growth. It is important to note that even if a child has high IQ, it must be stimulated and nourished constantly with new challenges.
Lehrke R. (1972) A theory of X-linkage of major intellectual traits. Am J Ment Defic; 76: 611-619.
Zechner, U. et. Al. (2001) A high density of X-linked genes for general cognitive ability: a run-away process shaping human evolution? Trends Genet; 17(12): 697-701.