depression

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.”

The 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."

A 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.