New studies, new lights
Of course, scientists continued to investigate this theory. Robert Lehrke, for example, revealed that most of childrens intelligence depends on the X chromosome, and he also showed that since women have two X chromosomes are twice as likely to inherit the characteristics related to intelligence.
Recently, researchers at the University of Ulm, Germany, studied the genes involved in the brain damage and found that many of these, especially those related to cognitive abilities, were on chromosome X. In fact, it is no coincidence that the intellectual disability is 30% more common in males.
But perhaps, one of the most interesting results in this sense comes from a longitudinal analysis conducted by the Medical Research Council Social and Public Health Sciences Unit in the Glasgow, Scotland. In this study they interviewed every year since 1994, 12,686 young people aged between 14 and 22 years. The researchers took into account several factors, from the color of the skin and education to socio-economic status. This way they found that the best predictor of intelligence was the IQ of the mother. In fact, the ratio of young people’s intelligence varied only an average of 15 points from that of their mothers.
Genetics is not the only responsible
If we leave genetics we can also meet other studies that reveal the mother plays an important role in the intellectual development of children, through the physical and emotional contact. In fact, some studies suggest that a secure bond is intimately tied to intelligence.
Researchers at the University of Minnesota, for example, found that children who have developed a strong attachment with their mothers develop a capacity of playing complex symbolic games at the age of two years, are most persevering and show less frustration during the troubleshooting.
This because the strong bond gives the necessary security to allow children explore the world and the confidence to solve problems without losing heart. In addition, these mothers also tend to help the children solving problems, thus helping to further stimulate their potential.
The importance of the emotional relationship for the development of the brain has been demonstrated by researchers at the University of Washington, who revealed for the first time that a secure bond and the love of the mother are crucial for the growth of some parts of the brain. These researchers have analyzed for seven years the way mothers relate with their children and have found that when supported emotionally their children and adequately gratified their intellectual and emotional needs, at age 13 the hippocampus of the kids was 10% greater than that of children of mothers who were emotionally distant. It is worth mentioning that the hippocampus is an area of the brain associated with memory, learning and stress response.
Can we really talk about hereditary intelligence?
It is estimated that between 40-60% of intelligence is hereditary. This means that the remaining percentage depends on environment. stimulation and personal characteristics. In fact, what we call intelligence is nothing more than the ability to solve problems. But the curious fact is that to solve problems, even a simple mathematical or physical one, comes also into play the limbic system, because our brain works as a whole. Thus, even if intelligence is closely linked to the rational thinking function, it is also influenced by intuition and emotions, that genetically speaking, are influenced by the contribution of the father.
Moreover, we must not forget that even if a child has a high IQ, we must stimulate his intelligence and nourish it throughout life with new challenges which are constantly improving. Otherwise intelligence will disperse.
Beyond what was stated by genetics, fathers should not be discouraged, because they also have much to contribute to the development of their children, especially being emotionally present. The IQ with which we are born is important, but not decisive.