You might have your dad’s smile, sense of humor, and athleticism, but when it comes to your wits, you’ve got more to thank your mom. Aside from cleaning after your mess, researchers revealed that your mom might also be the reason behind the high scores in your exams.
According to psychologist Jennifer Delgado Suárez’s post on Psychology Spot, past research shows intelligence comes from the X chromosomes. Unfortunately for your dad, he only has one of them (XY) while women have two (XX), making it twice as likely that all brains come from the maternal side of your genetic makeup.
Researchers also suggest that even if a child does inherit cognitive functions from their father, they may be automatically deactivated due to “conditioned genes” that behave differently depending on their origin.
These genes have a kind of biochemical tag which allows their origin to be traced even if they are active or not within the descendant cells. Interestingly, some of these genes work only if they come from the mother.
Intelligence is believed to be among these. If that same gene is inherited from the father, it is deactivated. In fact, advanced cognitive functions like thought, reasoning, and language occurring in the cerebral cortex were found to contain no paternal cells at all. Paternal genes ended up being found in the limbic system which controls functions like food, séx, and aggression.
Researchers in Glasgow even took a more human take on the evidence and found that, across a study of 12,686 young people, the mother’s IQ was actually the best predictor of intelligence.
However, it’s not all down to chromosomes and biology. A mother’s genetics isn’t the only thing that plays a role in intelligence. According to Suárez, physical and emotional contact from the mother is just as important.
“Researchers at the University of Washington 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,” she wrote. “When [mothers] adequately gratified their [children’s] intellectual and emotional needs, at age 13 the hippocampus of the kids was 10 percent greater than that of children of mothers who were emotionally distant.”
Suárez goes onto clarify that’s not to say dads aren’t important. “Of course, this is not to say that the relationship with the father should not be as fully developed, just that because of our social structure, including some of the gender stereotypes that remain, it is usually the mother that spends the most time with her small children,” she wrote.