A lot of people believe that kids inherit intelligence from their mothers. Some argue that it is scientifically proven. But what exactly is the actual truth? Read on to know what research has established.
Why do people think we inherit intelligence from mothers?
The factoid that intelligence is passed down only through your mother is aggressively moving across social media users’ trending bars after a September 14th, 2016 article published on a site called “Second Nexus” was reposted by notable accounts on different social media.
The claim has been checked by Snopes and found to be unproven.
As reported by Forbes the Second Nexus article’s main source of information for this “new research” was a woefully unintelligible March 2016 post from “Psychology Spot,” which cited a collection of studies that are decades old. They did not actually cite new research, and they misrepresented the science they used to make their claim, according to Snopes.
Fact: No, Research Has Not Established That You Inherited Your Intelligence From Your Mother.
According to Snopes, these internet claims are based on three main assumptions:
- There are specific and discrete genes that universally determine intelligence.
- Those genes are located on the X chromosome.
- That means that the genes must come from your mother.
Well, it’s all because of the X chromosome. Females have two X chromosomes and Intelligence genes are located on the X chromosomes. Therefore, it is highly likely that children will inherit intelligence from their mothers. But, there is a twist!
Genetics of Intelligence
As per prof David H Skuse, X-linked genes are relatively highly specialized for brain development (but not intelligence) relative to other genes from the rest of the genome, which do not equate to intelligence. And women get one of their two X chromosomes from their father. Despite having two X chromosomes, only one X chromosome is active in each cell of the female.
So, does intelligence come from the mother? Intelligence is inherited from the mother or father?
Tough to say! Isn’t it?
What researchers say about kids inheriting intelligence from mothers?
Two X chromosomes that a woman carries are not identical. She must have inherited one of them from her mother and the other from her father. When she delivers a child, she passes only one X chromosome to her child after two X chromosomes engage a little genetic swapping themselves. Her child receives the second chromosome from the father.
A mother can pass the X chromosome to both daughter and son, but a father mainly passes the X chromosome to a daughter. Sons get their single X from the mother of course. Since a mother doesn’t carry two identical X chromosomes, they don’t increase the odds of inheriting a specific variant.
That’s not all. There are many people carrying two X chromosomes (doubled gene dosage), but some people walk around with just one X chromosome. People with doubled gene dosage have most of the one X or the other turned off by each cell.
So, even when a person inherits an X-linked gene variant, it may or may not be used because some cells might just shut it down.
Every person has at least one X chromosome and Mother Nature doles them out to all of us – And you get an X chromosome, and you get an X chromosome! And so do you!
Once you inherit an X chromosome, short of a major deletion, you only receive whatever genes (linked to intelligence or not) are still present on that X chromosome.
A lot of articles on the internet created a big buzz with headlines “we inherit our intelligence from our mothers…” But, the editorial staff of those popular articles is only emphasizing gene variants that might be linked to intelligence and not just genes.
According to researchers, even if a person inherits half of their intelligence from their mother, that proportion is in turn fractured into several genetic variants scattered across our genomes. In short, this whole process of inheriting intelligence is quite complicated.