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Science confirms viral theory about inheriting your mom's nervous system—and it explains a lot

“My mom really said, ‘Double it and give it to the next person.’”

Mother struggling to comfort her child.

Think about the last time your mom—whom you love and cherish—handled a situation poorly. Maybe she lost her temper while waiting to "speak to a representative" on the phone, or raised her voice in a moment that didn't warrant it. To be clear, mothers are not the only ones who lose their cool (we'll save analyzing your other family members' questionable behaviors for another time). But since they contribute 50% of our DNA, their unique responses to stress—their triggers, defense mechanisms, and attempts at self-soothing—deserve a second look. Because, as hoards of people on TikTok are now discovering, we inherit far more than just eye color and a winning smile from our moms.

Thanks to a viral video posted by TikTok user @sierraalexndraa (also known as Sierra Saltz, a chronic illness advocate and content creator who uses her platform to explore the connections between health, energy, and intentional living), people are discovering the complex, surprising world of genetic inheritance. The post, which has garnered 15 million views and 2.4 million likes, has sparked intense discussions about passed-on family traits, inherited emotional regulation, and that maybe, we really have no choice but to turn into our mothers.


"Did you know that you didn't just inherit your mom's genes, you inherited her nervous system, too?" Sierra asks. "From the moment we're in the womb, we're absorbing our mother's emotional state, her stress levels, and even the way she regulates her own nervous system."

The news shocked the Internet, with comments ranging from vulnerable ("You forgot to hold my hand 🥺," wrote one person) to outright denial ("Great, thank you, wish it didn't, moving on," replied another).

But the most common response? "Well, this explains a lot…"


But is Sierra’s claim really true? Do we really inherit our mother’s nervous system? There was only one way to find out: We turned to science to try to explain this phenomenon. Here’s what we found.


The science behind “inheriting your mother’s nervous system”

Mitochondria tells the story. Yes, you inherit your mom’s nervous system—and your dad’s, too, don't forget. “It’s one of the basic tenets of biology: We get our DNA from our mom and our dad,” explains medical science writer Lisa Marshall. “But one notable exception has perplexed scientists for decades.”

It’s the mitochondria, the famed “powerhouse of the cell.”


mothers, science, mitochondria, genetics, nervous systemThe mitochondria is the powerhouse of the cell. Photo credit: Canva

Humans, along with most animals, only inherit mitochondrial DNA from their mothers—the result of a strange anomaly in the procreation cycle, as “all traces” of the male mitochondrial genome are obliterated the moment the sperm meets egg.

Why is this important? Well, it turns out that mitochondria are involved in almost every aspect of the human body. “The nervous system cannot possibly function without the mitochondria,” explain Dutch psychological scientist Peter Kramer and research scientist Paola Bressan in the research article titled “Our (Mother’s) Mitochondria and Our Mind.”

Besides providing our bodies with energy, these specialized powerhouses also regulate calcium in neurons, ensures synapse formation and the creation of new neurons, and maintains the delicate balance between cell survival and programmed cell death (apoptosis). Which might sound like a bunch of A.P. Biology buzzwords shoved together, for those not in the medical field.

But just imagine the humble mitochondria, working overtime to make sure everything’s in order: that our senses work, our motive skills are up-to-code, memories are created, and hormones are properly released. Unbeknownst to most, the mitochondria in our bodies are taking care of us. Almost like… a mom.


But when things go haywire, a bunch of problems tend to follow. “A place where mitochondrial trouble occurs frequently is the brain,” writes Kramer and Bressan. So, “it is hardly accidental that their malfunctioning has been associated with virtually every mental or neurological affliction on earth, including chronic psychological stress and fatigue, cognitive deficits, Alzheimer’s and Parkinson’s disease, anxiety, depression, bipolar disorder, schizophrenia, autism, multiple sclerosis, and Down syndrome.”

It’s not just genetics. Beyond the cellular level, a child’s ability to tolerate stress and self-soothe begins in the womb. Research suggests that chronic maternal stress experienced during pregnancy isn't just felt by the mom, but her baby as well—potentially wreaking havoc on the child’s stress-response systems before they're even born, which could lead to future psychological complexes around relaxation and emotional equilibrium.

There’s a unique mother-daughter connection, too. A groundbreaking UC San Francisco study found that the corticolimbic system—a fancy term for the part of the brain that’s in charge of emotional regulation and is often linked with mood disorders—is “more likely to be passed down from mothers to daughters” than to sons.


There’s no need to panic

While there's a clear connection between your nervous system and your mom's, it's important to understand that this isn't the complete story. As Dr. Fumiko Hoeft, a UCSF associate professor of psychiatry who led that groundbreaking study, stresses, "The finding does not mean that mothers are necessarily responsible for their daughters' depression. Many factors play a role in depression—genes that are not inherited from the mother, social environment and life experiences, to name only three. Mother-daughter transmission is just one piece of it."


mothers, science, mitochondria, genetics, nervous systemA pregnant mother taking a deep breath.Photo credit: Canva

Also, give your mom some credit! “We are more likely to inherit the good and the bad parts of our mother’s nervous system,” Dr. Natalie Jones, a licensed psychotherapist, says. “If your mother is calm, nurturing, and manages stress well, chances are you are likely to manage things in a similar fashion.”


Inheritance does not equal destiny

The mitochondria given to you at birth are just that—nothing more. Even nervous systems can be rewired (once you're out of the womb, that is). Through engaging in neuroplasticity-boosting activities daily, like physical exercise, learning new skills (hello, Duolingo), and mind-body techniques like yoga and meditation that lower stress hormones, your nervous system can be profoundly reshaped. Your mitochondria will thank you.

Huntington's disease is caused by a single mutation in someone's DNA.

A normal protein, huntingtin, becomes warped and toxic. Over time, the toxic protein builds up, killing a person's brain cells and slowly robbing them of cognitive and motor control.

It affects about 30,000 Americans, often shows up later in life, and is fatal. Because it's a genetic disease, it can be passed down through families. It's cruel, unfair, and nobody deserves it.


But what if we could just zap away that one fatal mutation?

That's exactly what a team of scientists from Emory University and the Chinese Academy of Sciences just tried — zapping that mutation right out of the DNA. And it looks like it could work.

Working with sick mice in a lab, the scientists used a gene-editing technique colloquially known as CRISPR. On June 19, 2017, the scientists reported that once injected and inside the brain cells, the CRISPR system could read the mice's DNA, find the huntingtin gene, and snip it apart. This effectively silenced the gene, cutting off the "flow" of the toxic proteins.

When the scientists checked on the mice a few weeks later, the toxic proteins had nearly disappeared from their cells. The scientists reported that the sick mice also regained some, but not all, of their motor control.

This isn't the first trial to use gene editing on Huntington's, but it does represent a new technique.

There's currently no cure for this awful disease, but this kind of research could provide a path to one in the future.

Gene editing is still pretty new; we need to learn more about whether CRISPR is completely safe, for instance, or what the long-term effects of silencing that particular gene would be.

But if we look at the history of humanity, we've conquered many horrible diseases. We've beaten back polio and smallpox and are even tackling childhood cancer. It's not far-fetched to think that, one day, we may be able to add Huntington's to the list.

More

How one man’s DNA results influenced his work as a culinary historian and a food writer.

What do food and family heritage have in common? Well, for Michael Twitty, a lot.

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AncestryDNA

What did you have for dinner last night?

Do you think your great-grandmother — or great-great-grandmother — ate the same thing for dinner? Chances are, you probably haven't given much thought to why your meal is what it is — or whether your great-grandparents ever ate the same thing.

All images via Michael Twitty, used with permission.


But ever since he was a child, culinary historian Michael Twitty has thought about these kinds of questions.So when Twitty became curious about his own ancestral roots, food was always going to be a part of his research journey.

When he combined these two passions — culinary history and genealogy — it led him on an incredible trip exploring the food and history of the old South, one that would change how he saw his family's role in history and culture forever.

Twitty decided to embark on a journey to learn the truth about his heritage by taking an AncestryDNA test.

"For African-Americans, the desire to know what makes up your conglomerate blackness is deep," Twitty says."It's in every one of us, and we take that journey very seriously. We want to know who we are and where we come from ... because of slavery."

Not only did he want to know where his family came from but also whether some of the stories passed down in his family were true — including the stories about his white ancestors, the people who had once held his family in bondage.

"We had an incredible oral history that said a lot of things about who we were," he says, "and quite frankly, we couldn't always prove those things."

For example, he had been told that his ancestor was a captain, and his family believed they knew his name and the story of how his great-great-great-grandmother was born, but there was no way to prove it, no birth certificate to name him as the father, because she was born a slave.

Twitty not only wanted answers, he wanted to understand what it was like to live his ancestors' life. So, he embarked on a journey from Maryland to Texas and back again.

During that time, he immersed himself in old records, bills of sale, and other historical documents on Ancestry.com.

He also visited restored plantations, farms, and battlefields.

He met with a 101-year-old man who had lived through the Jim Crow years, he spoke with Civil War re-enactors, and he spent a lot of time eating and cooking alongside black, white, Native American, Latino, and Asian chefs to understand their role in the shaping of southern history and culture.

To better understand his ancestor’s experience, he picked cotton for 16 hours, primed tobacco, plucked Carolina rice, cut sugar cane, and sucked on red clay.

He also took an AncestryDNA test to get to his genetic roots.

The results revealed that his origins were 69% African and 28% European. His ancestors had come from such places as Ghana, Senegal, Congo, and Nigeria while his European ancestors were largely from Scandinavia and the Iberian peninsula.

Michael Twitty's AncestryDNA results.

He encouraged others in his family to take the tests too — including his grandfather, an uncle, and his cousins — and because his AncestryDNA results allowed him to compare his DNA against a large population of others who had also taken the test, he was able to slowly piece together a much clearer picture of who his family was, where they came from, and how they moved around the United States.  

In fact, with the help of his AncestryDNA results and records from Ancestry.com, he was able to identify and name at least a dozen new ancestors, black and white, going back two centuries — helping him prove that a lot of those old family stories were, in fact, true.

"When you can actually take your genealogy — your genetic genealogy — and see that yes, indeed, you are a part of these historical practices, migrations, journeys. When history is a narrative … all of the sudden, you're real," Twitty says. "You're real in a way that a book can't tell you that you're real."

This trip also showed him how much his family's story overlapped with the history of today's "southern cuisine."

The forced migration of domestic slaves transformed food in the region because cooks brought their tastes for certain food with them. And his family was a part of that story.

For example, he says, "soul food was a cuisine, a memory cuisine brought by people who were migrating to other parts of the country from the South, but it was based on that survival cuisine that we made in the old South that kept us going for generations."

Twitty's quest to learn more about himself and his roots had a dramatic effect on his work as a culinary historian and food writer.

It changed how he saw the role of food both in his family and in the old South as a whole — and it changed how he felt about history. Knowing who his ancestors were, seeing the records of their lives, learning where they were from, and discovering the role that they played in the history of food and the South brought that history alive for him in a way nothing else could.

This led him to write a book called "The Cooking Gene," which will be available this August.

"I wanted to take our entire country on a journey, and I wanted to use that information from the ancestry test to backup my claims," Twitty says.

"This is where soul food comes from in Africa — look at my genes. My genes show that yes, it did come from Nigeria and Senegal and Congo and Ghana and other places. That story is in our blood — it's in our bones."

Twitty believes others might find themselves creatively inspired by their results too. "Your AncestryDNA results can be a new way into whatever your creative passion [is]," he says."A memoir or cookbook is just one outlet, it could be a quilt, a garden, a social media group, a novel, you might travel ... your results are an infinite invitation."

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AncestryDNA

When Shayna Watson decided to get an AncestryDNA test to reveal her ancestry on her 30th birthday, she had a certain idea of what the results would look like.

"I expected to see African, I expected to see a little bit of European, just based on colonization, and I definitely expected to see at least a little Native American," she says.

Watson had grown up with stories of her partial Native American heritage. In fact, her father had proudly shown her photographs of her grandmother on a Pequot reservation.  


When Watson was asked, frequently, throughout her childhood and adulthood, "What are you mixed with?" in regards to her distinctive curly hair, she had responded with "Native American" — although she had never known for sure.

Image courtesy of Shayna Watson.

"I get my ancestry results back and there's not even a drop of Native American," she says.

"It was a shock."

Immediately, she took a screenshot of the results and sent them to her mother, followed only by a question mark. Questions initially popped into her head — like "Am I adopted?" "Is my dad really my dad?" But that wasn’t it. She wasn't adopted. And her dad was her dad. There was just more to the story.

Screenshot of AncestryDNA results via Shayna Watson.

"It made everybody kind of stop and recognize that a lot of the oral history that we know in our family may not be true," she explains. "It opened up this conversation of whether my grandma was passing as Native American at the time."

That discovery led Watson to some difficult questions about her family's history. Had her grandmother been told the same stories she had? Or did she have to downplay her African heritage because of anti-black sentiment she faced?

Watson continues, "I think what the DNA test did that was great for me and my family was that it kind of allowed a truth to be told without people having to tell the truth."

Screenshot of AncestryDNA map results via Shayna Watson.

The experience has even inspired Watson's mom to take her own AncestryDNA test, and she is eagerly awaiting the results.

In addition to revealing her family’s past, the AncestryDNA test results helped Watson better understand how her ancestry can inform her identity.

Once the initial shock of not having any Native American heritage died down a little, Watson was able to really process her results, which showed that 73% of her ancestors came from the continent of Africa and 25% came from Europe, mostly Scandinavian regions.

"I was kind of pleasantly surprised with the percentage African-American that was there," she says. "With us black Americans, it's not an easy narrative to come back and see such a large percentage of European because, for a lot of us, we know what that means. We know the tough history behind that."

Seeing such a large African percentage, she felt relief.

Finding out her family history and where they came from, she says, has given her more confidence in her identity as a black woman. Knowing that some of the unique physical characteristics she receives compliments on are, in fact, a result of her African ancestry has become a source of pride for her.

Image courtesy of Shayna Watson.

"There was a lot of times when I was growing up that I kind of clung to this idea that I was mixed with a bunch of things and I used that to set myself apart a little bit," she says.

"Now when people ask if I am mixed with something, I say 'no,'" Watson says.

"Hearing that question again as an adult," she wrote in her article for The Root, "especially now — when I know the legacy of squeezing into spaces in order to exist that has come out in my history — has really shifted the way I view beauty and blackness."

Watson is a writer by career, and while telling her story to others, she found it resonated with a lot of people. So, she decided to write about her experiences of digging into her ancestry in the hopes of inspiring others to do the same.  

"I think for those of us that are labelled as minorities in this country, it's a difficult place to find where you fit in," Watson says. "What this allowed me to do was decide for myself — even though the results came back with six different places I was connected to — it allowed me to decide where I wanted to identify."

For her birthday this past year, Watson took a vacation to Africa and spent a lot of time exploring Morocco.

Watson on her trip in Morocco. Image courtesy of Shayna Watson.

"That trip … it definitely felt different, just knowing that such a huge percentage of me was from where I was standing," she says. "And it definitely makes me want to go back and visit Nigeria and Congo and all of the places that showed up on my results that I never knew I had a direct connection to without doing this test."

Watson says that she recommends that other people take the test too even if they think that they know what the test will show.  

"There are so many things in your ancestry that  your  family may never know to tell you ... It lets you get a part of [your past] that you could never get just from talking to people and family members," she says. "Even if you think that you know, and even if every story going back in your family is from a certain place, I would still suggest doing it because we are such a melting pot and it's a beautiful thing."

Did you know? April 25 is DNA Day. Have you celebrated your heritage today?