Not the point of the post. The point is that, no, you don't inherit your intelligence from your mom. At least not completely. In a recent post for Forbes, science writer Emily Willingham ripped this post to shreds:
A garbled post from a website called Second Nexus has gone viral in my feeds (and possibly yours), likely because of its eye-catching headline claim that “New Research Establishes That Intelligence Is Inherited From The Mother.” The piece is bylined “Editorial Staff,” presumably because everyone was too embarrassed to put a real name on it.Ouch. She goes on to offer some education on genetics, including that 1) women "tend to" have two X chromosomes (but not always), 2) one of those X's had to come from the father, 3) and having two X's doesn't double your odds for receiving some trait because cells might shut down most of one X, reducing its influence.
But more than that, she offers a far more complex view of intelligence, reminding her audience that only about half of what we call intelligence comes from genes:
While maybe half of our intelligence as we currently define and measure it is inherited, that proportion is in turn fractured into many many genetic variants scattered across our genomes. These variants operate together in various ways to form what we view as intelligence. And each of those fragments of heredity that contributes is itself subject to a host of environmental factors, both in its immediate molecular world and inputs to the whole organism, that will influence function. And that influence continues after birth as an ongoing mutual interplay of gene variants and environment. It’s layer upon layer upon layer of interacting pieces. So no. Not just your mother. Not just the X chromosome. Not even just genes.Willingham then traces back the sources the original post used to make its claims, including Psychology Spot (a blog she calls "a dumpster fire of poor information about genetics and embryonic development"), and Cosmopolitan.
I saw many of my friends, including fellow scientists, share this hot mess of a post. Why? Willingham has one potential explanation:
Those headlines. It’s an irresistible invitation to humblebragging, whether you have a mother and think you’re a genius or you are a mother and think your children are geniuses or you’re feeling feminist and want to stake a claim that women bring the smarts to this world. That’s a pretty solid built-in audience ready to click…and share.This is not to say mothers aren't important for their children's development and intelligence. About half of our intelligence comes from genes, and short of genetic engineering, there's not a lot we can do about that. But the other half seem to be environmentally influenced. Mothers (and fathers, and really anyone interacting with children) have a lot more control here. For instance, some research shows that offering growing infants lots of stimulation can result in more developed brains - the environment can actually influence the physical. Taking children out to see the world, and experience new things, does enrich them and boost their intelligence. (Note: this is real stimulation, not on a screen - though some would argue television has deleterious effects on children, the most we can say from research is that it has no effect. And don't get me started on the Baby Einstein videos...)
In my case, I know my mom is responsible for a lot of my intelligence, not just from genetics, but from offering an enriching world. She would teach me new words and ask me to try to use them in a sentence that day. I was probably the only first-grader who knew "tumultuous." She taught me the difference between independent and dependent variables when I entered a science fair in 7th grade. And she instilled me the curiosity that continues to influence my efforts today. She's also the reason I write.
Regardless of what genes were passed on (or not), there's a lot we can do for children.