If you have a high IQ you may want to thank your mother.
That is because intelligence, among other genes, come from either your mom or dad.
Each person’s genetic code is made up of roughly 20,000 genes that determine what traits are expressed in their physical characteristics, health and even personality.
Some traits are linked to a single gene – such as eye color, freckles and dimples – whereas others are determined by multiple genes, such as hair color and height.
There are many different ways that people inherit genes from their parents.
The first is through a dominant gene – which only needs to be passed down from one parent in order for the associated trait to be expressed in their child. Recessive genes, by comparison, need to be passed down by both parents to be expressed.
Brown eyes are one example of a dominant genetic trait. If one parent has them, their child is very likely to inherit them. Blue eyes, on the other hand, are recessive – so both parents must carry that gene in order for their child to have them.
But there are also more complex gene inheritance patterns, the most common of which is X-linked inheritance.
X-linked traits are influenced by gene variants on the X chromosome. Hair color is one example, as well as conditions like sickle cell anemia or cystic fibrosis.
Children generally inherit a 50/50 split of their parents’ respective genes. But certain traits are more likely to come from mom than dad, and vice versa
Intelligence: Mom
Intelligence is another example of an X-linked trait. And because women carry two X chromosomes and men only carry one, women are twice as likely to pass on traits related to intelligence, research has shown.
A 2006 study conducted by the Medical Research Council Social and Public Health Sciences Unit in Glasgow, Scotland, interviewed 12,686 people from the ages of 14 to 22 every year between 1994 and 2004.
They found that the IQ of each study participant varied only 15 points on average from their mother’s.
Thus, the researchers concluded that the strongest predictor of a person’s intelligence is their mother’s IQ.
Famous American actress and filmmaker Jodie Foster and her two sons are an example of this.
She has an ‘genius’ IQ of 132, reportedly taught herself to read at the age of tree and was high school valedictorian.
Her sons appear to have inherited their mother’s above average intelligence. Her eldest, Charlie attended his mom’s alma mater, Yale University, and is pursuing a career in acting. Her youngest, Kit, is a research scientist at Princeton University.
Famous American actress and filmmaker Jodie Foster and her two sons are an example of this. She has an ‘genius’ IQ of 132, reportedly taught herself to read at the age of tree and was high school valedictorian
But genetics aren’t the only factor that influences intelligence.
In fact, twin studies suggest that only about 40 percent of intelligence is hereditary. Environmental factors account for the other 60 percent, such as education, nutrition and health.
Early puberty: Dad
Were you an early bloomer? If so, blame your dad.
A 2013 study published in the New England Journal of Medicine found that mutations in the MKRN3 gene are linked to starting puberty early, i.e. before age eight in girls and before age nine in boys.
For this study, researchers screened the genomes of 32 people who had gone through early puberty from 15 families.
They found mutations in the MKRN3 gene in 15 people from five of the families.
In all of these cases, the mutated gene had been inherited from the father.
The researchers concluded that these mutations ‘release the brake’ on puberty, causing children to begin this chapter of adolescence sooner than their peers.
But like intelligence, genetics aren’t the only factor that influences the onset of puberty.
While the exact cause of early puberty often can’t be found in individual cases, other potential drivers include hormonal medication, cancer and diet.
ADHD: Mom
Mel B (right) and her daughter have both been diagnosed with ADHD
If you have Attention Deficit/Hyperactivity Disorder (ADHD), it may be a result of genes that influence your mom’s brain chemistry.
A 2010 study published in JAMA Psychiatry found that children whose mothers had below-normal serotonin levels were 1.5 to 2.5 times more likely to develop ADHD than those whose mothers had normal or levels.
Serotonin is a hormone that carries messages between nerve cells in the brain and throughout the body.
It plays a particularly important role in regulating mood, sleep. digestion and sexual desire.
The production of this hormone is regulated by multiple genes, but the primary ones are TPH1 and TPH2. Certain mutations in these genes can impair serotonin production, and mothers who had them were more likely to have kids with ADHD.
Mel B (Melanie Brown) who was part of the hit pop group ‘The Spice Girls’ revealed in 2019 that she had been diagnosed with ADHD, along with anxiety, dyspraxia, dyslexia.
Her daughter, Phoenix, told Teen Vogue in 2023 that she had also been diagnosed with the disorder.
Fertility: Dad
A daughter’s fertility may be affected by a gene inherited from her father.
Human egg cells have centrioles, or cylindrical organelles involved in the development of spindle fibers during cell division. But this part of the egg cell is naturally eliminated during the development process.
If the centrioles are not eliminated, then the egg cell will not be viable.
Nicole Kidman (right), pictured with her father, has suffered from infertility and pregnancy loss
A 2016 study published in the journal Science found that some women become infertile because they inherit a dysfunctional gene from their fathers that prevents centrioles from being eliminated from their egg cells.
Nicole Kidman has shared the challenges and heartaches of infertility, including how she suffered through an ectopic pregnancy, miscarriages and failed treatments.
It was not until 2008 at the age of 41 did she give birth to her first biological daughter through IVF.
Sleeping patterns: Mom
If you struggle with insomnia, chances are your mom does too.
A 2023 study published in the Journal of Child Psychology and Psychiatry found that children of women with insomnia are more likely to develop insomnia themselves.
This suggests that children can inherit a predisposition for the sleep disorder from their mothers.
In fact, roughly 35 percent of people with insomnia have a family history of the disorder, with the mother being the most commonly affected family mother, according to a 2012 review.
But insomnia is a complex disorder that is often caused by multiple converging factors. Just because your mom has it, that does not necessarily mean you will, through it does increase your risk.
