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Session 303: How Trauma Affects the Brain

The Therapy for Black Girls Podcast is a weekly conversation with Dr. Joy Harden Bradford, a licensed Psychologist in Atlanta, Georgia, about all things mental health, personal development, and all the small decisions we can make to become the best possible versions of ourselves.

Due to the dedicated work of so many brilliant scientists like our guest today, we have learned and continue to learn so much about how the traumatic experiences of our parents, grandparents and other ancestors are passed down. Today we’re diving into an exploration of intergenerational trauma with our guest, Dr. Bianca Jones Marlin.

Dr. Marlin is a neuroscientist and Herbert and Florence Irving Assistant Professor of Cell Research at the Zuckerman Institute at Columbia University in New York City. She studies how information learned can be passed down to future generations through transgenerational epigenetic inheritance. It’s all about understanding how traits and behaviors are passed on through generations, shaping how we act and behave. During our conversation she breaks down the science behind generational trauma and how trauma manifests in our bodies, brains, and everyday lives.

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Session 303: How Trauma Affects the Brain

Dr. Joy: Hey y'all! Thanks so much for joining me for Session 303 of the Therapy for Black Girls Podcast. We'll get right into our conversation after a word from our sponsors.

[SPONSORS' MESSAGES & Dr. Joy's Webby Award CTA]

Dr. Joy: Due to the dedicated work of so many brilliant scientists like our guest today, we have learned and continue to learn so much about how the traumatic experiences of our parents, grandparents, and other ancestors are passed down. We're diving into an exploration of intergenerational trauma with our guest today. Dr. Bianca Jones Marlin is a neuroscientist and Herbert and Florence Irving Assistant Professor of Cell Research at the Zuckerman Institute at Columbia University in New York City. Dr. Marlin studies how information learned can be passed down to future generations through transgenerational epigenetic inheritance.

It's all about understanding how traits and behaviors are passed on through generations, shaping how we act and behave. In our conversation today, Dr. Marlin breaks down the science behind generational trauma and how trauma manifests in our bodies, brains, and everyday lives. If something resonates with you while enjoying our conversation, please share it with us on social media using the hashtag #TBGinSession, or join us over in the Sister Circle to talk more in depth about the episode. You can join us at Here's our conversation.

Dr. Joy: Thank you so much for joining us today, Dr. Marlin.

Dr. Marlin: Thank you so much for having me.

Dr. Joy: I'd love if you could get us started by talking about what you do as a neuroscientist and how you got interested in neuroscience and behavior.

Dr. Marlin: What I do as a neuroscientist, I really think I have an amazing job because I get to ask questions that interest me about education, about learning, about stress, and about survival. And I have an amazing, talented group of students and trainees and fellow scientists who dive in and really look at the answers, the mechanisms, the biological aspects of these questions that we ask.

Dr. Joy: And how'd you get interested in it?

Dr. Marlin: How did I get interested in neuroscience? I started off studying adolescent education, so I was a seventh through 12th grade teacher in biology. And what I began to note during my studies as a teacher is that some of my students, I could almost tell how their day was going based on their attention in my class. And I really want to be clear with speaking about my students because it wasn't as if those that came from "bad homes" were "bad performing" in school. No, there were students who were coming from difficult situations, and I couldn't get them to pay attention in my class. And that makes total sense because if you are thinking about whether or not your siblings are safe, or whether or not your mom is okay, or how stable your household is at home, it would not make evolutionary sound sense for you to be worrying about differential equations when you're worried about what's going on at home. And so I really say it as in honoring their experiences.

But I noticed that there were certain ways I could pick up what was going on in the household based on what was happening in the classroom and it did affect their performance the way that we standardize it as teachers. And I really wanted to look into how to optimize how stress changes learning in the brain.
And I realized as educators, we didn't have much information as to how the brain worked and it was almost as if there were these scientists that had this information, but they didn't speak to educators. And so how do we bridge that gap? And so instead of bridging that gap, I became a neuroscientist and now explore how the brain adapts to parenthood for optimization of parents, how the brain adapts to stress and trauma and what that looks like, to inform our kids for many generations to come.

Dr. Joy: Had you known you wanted to go to school beyond where you had gone to become a teacher? Or was it only in exploring these questions that you decided, "I'm gonna go back to school and do something else now"?

Dr. Marlin: Oh my gosh, no, I didn't know at all that it was an option. My heart breaks a little bit every time I say that. To think that I'm here where I am now, I'm a professor at a prestigious institution, and I didn't know this was an option. I thought if you loved biology, you could go into med school and become a doctor, or you become a science teacher. And the way that I understood doctor – working in a hospital – I didn't feel that pull, an educator was like, well, this makes sense, I guess this is what I will do. I respect so many teachers that go through it and dedicate their lives to that. It was only as I was studying to be a teacher, biology teacher (and I dual majored, I actually did biology and adolescent education, so I dove straight into biology) that I realized like, oh, there's this whole facet. You become a scientist through something called a PhD that's not just a doctor of philosophy and thinking about philosophy. You actually can do hands-on, wear gloves and do science, and that's a career choice. Like my professors who taught me had PhDs. And then it opened up this whole realm that I didn't know existed and it led me to where I am now.

Dr. Joy: Nice. Thank you for sharing that. Something that you spend a lot of time studying and that has become more of a term people are familiar with recently is transgenerational epigenetics or generational trauma. Those sound like very big words I think for a lot of us. Like, what in the world does any of that mean? So I wonder if you could give us a 101. What are we talking about when we say transgenerational epigenetics?

Dr. Marlin: Transgenerational. Let's break the whole word down. Transgenerational, trans meaning across generations. When we talk about transgenerational, what we're really referring to is a person… Let's talk about humans for a second. So a person, their grandchild would be considered transgenerational to them. Their child would be considered intergenerational. And the reason that we highlight those two differences is because when we're speaking about something being passed on through generations, my mother can pass something on to me genetically or through a conversation at the dinner table because I grew up with her, because I was constantly around her. Whereas in many situations, a grandparent, you could actually be born never knowing your grandparent. You can't be born never knowing your mother or never really interacting or having at least some connection with your mother. So intergenerational is mom-offspring, dad-offspring. Transgenerational are the grandkids. So we've got that part down.

The trans-generational epigenetic, what does that mean? Genetic, our DNA, what makes up who we are, that's the same in every one of the cells in our body. Epigenetics means above the genome, and it really is just describing these markers (we'll call them for right now) that scientists observed in the genome. So what does this mean? Our genetics are the same in every cell in our body, which means your DNA in your liver and the DNA in your skin and the DNA in your eyes, those are all the same DNA. But how do we have liver cells, eye cells, and we don't have teeth growing in our eyes? It's because certain parts of our genome can be "read" so seen, or "unread" or unseen, and that's the epigenetic component. There's certain markers that say "you're a liver cell so make your liver, do your liver thing, and you're an eye cell, so don't make liver components of your DNA." And those epigenetic markers are what differentiate certain cells from another.

When we talk about transgenerational (across generations) epigenetic (above the genome) inheritance, it's when an experience in a grandparent changes those markers that say, "become this, don't become that," and those changes are inherited in the next generation. Because we thought for a long time those changes happen, but it doesn't get passed onto the next generation because it's not actually the DNA – it's just stuff around the DNA. We're coming to see that those things around the DNA or things that change those things around the DNA are somehow being passed down. And this is really the crux of the Marlin Lab and what we study.

Dr. Joy: So we don't necessarily have any firm answers yet, but this is a part of what you are learning. We do know that it happens and a part of what you're studying is like how this happens.

Dr. Marlin: And particularly how this happens in response to stress and trauma, and how much of this is adaptive versus maladaptive. This is really what we focus on.

Dr. Joy: Got it. We talk a lot in psychology around like trauma getting trapped in the brain and our body experiencing trauma. Can you talk about what actually happens in the brain when we have had a traumatic experience?

Dr. Marlin: What happens in the brain when we have a traumatic experience? I'll start off by saying I'm a firm believer that biology wants us to survive and thrive, so any change the body has is a hopeful potential adaptation to the stimulus. What we've come to see, both as humans (as we see this as we live on this earth and walk throughout life) but also as biologists, is that certain stressors, certain traumas change the way we respond to future stressors and traumas because we've learned a different response. So that learning mechanism, that's beautiful, that's in the brain, that's well established, that's well studied, I would say – how the brain learns. And it would make sense that if you are, let's give an example of like you're walking down the block and all of a sudden you walk past the baseball field and a ball comes whizzing behind you, you jump back. The next time you walk past that baseball field, you'll keep your eyes open both ways as you're crossing the street.

That heightened alertness that, "ooh, let me be very much aware of my surroundings" is essential for your survival for you to get to work looking cute, and wherever you're going, and not get hit by this baseball. But when you're walking throughout life and you're not just walking past a baseball field, and you feel that constant… everywhere. "Something bad could happen." This is when it becomes maladaptive. So this is what really us as neuroscientists, the group of us that are studying these facets, are really looking at. What does it mean to learn one experience, generalize it to experiences that really it doesn't fit, and then potentially even take those memories of that one bad experience that could have been helpful in learning something (although it was an unfortunate experience), and passing it down to the next generation. Where they don't live anywhere near a baseball court, but they feel that tension every time they walk down the street.

Dr. Joy: So many things are going on in my head as you're talking about this, Dr. Marlin, and I know you've also talked a lot about racism as a traumatic experience and how that changes the DNA and changes our brain matter as black people. Like when you have had racist experiences and you're kind of looking for this baseball all the time, that does change the way we kind of show up in the world.

Dr. Marlin: Yes. I guess the unfortunate part of my work, but also the unfortunate part of my life of this study is that, do we have exact mechanisms in which racial stress changes these molecules that change this DNA? No. But we do know that… let's speak about America for example. Black Americans who are descendants of slaves are more likely to suffer from hypertension, which is high blood pressure, diabetes. Could it possibly be that what we understand and what we know as a black population, and what we experience as a black population, could have a biological ramification and mechanism? I think it's pretty unfortunate that we haven't put our finger on that. It's understudied in the realm of biology, but we know it as a people group and we know it as Americans, as all Americans, as people who come to America, people who have studied America. People all over the world see this. So we see it with our eyes but if we don't have it written down in a biological manner or written down in a first primary research publication, it's almost as if it's not really true, dare I say. And so, although I use mice in my studies, the questions that we're asking, I really hope that people take that and take it to the next level. If this is the biological mechanism that we've seen in rodents, what could it mean?

To stress a rodent, very simple, we do something like a light foot shock. The rodent's a little bit bent out of shape, and we see changes in the brain and body. What could it mean for generation upon generation of blatant trauma on a people group? And I also wanna specify by saying black people aren't the only ones traumatized by the history of slavery. Because in order to induct and induce and maintain slavery, there's another population, the white population, that had to do that. And I think it hurts us as a society if we don't address that as well. Not to put blame on where we are in 2020, but to acknowledge that ignoring that you have ancestors who for generation upon generation said yes to slavery and made a conclusion that they're better than another people group, that's damaging. And that's the level of damage that we also haven't dug into as a society because it's scary to some people. And I think we're doing damage to ourselves as a country, as a world, as our environment, by not addressing those things. Now is it exactly what my lab does? No. We still stick to the mice. But I hope that it informs those who take it to the next level.

Dr. Joy: More from my conversation with Dr. Marlin after the break.

[BREAK & Dr. Joy's Webby Award CTA]

Dr. Joy: Can you give us some examples of how trauma manifests in our bodies, brains, and everyday lives? What does this continued stress look like?

Dr. Marlin: In our model organism, the mouse, what we do is we have an animal use its senses. So we explore the world, all mammals (including humans), we explore the world through smell, through sound, through taste, through touch. We use these senses, and we explore the circuits of these senses in the brain and see if they change and how they change with trauma – both in the parent and then it changes throughout generations. So we're following up on really exciting work done by former labs that have shown that if you have a smell and you pair that with a light foot shock, it seems to change the structure in the brain and somehow that's inherited and passed onto the next generation.

I'm saying these things and I know I'm saying it as a scientist, so you may just be like, oh yeah, that makes sense. Okay, cool because she's a scientist. This is astounding. This is not something we should take lightly. An experience in a mammal is changing the structure of the brain. Biology doesn't waste energy, so if the structure's changing and neurons are changing, that's a really big deal. And so this small stressor can change the smell neurons in a mammal and then somehow that message is getting from the nose (in these studies, we use males) so it's getting from the nose to the testicles to the sperm somehow, being passed on to the next generation. So this sperm meets the egg, gets implanted into a female who's never met anyone else and then her kids are born with a change in structure. Her kids are born with their daddy's issues, the kids are born with a change in brain structure and so we're really looking at what that means. Are these offspring more anxious when they smell a smell? Are they more sensitive to things? Or are they ready to take on an environment in which this odor may come into play and survive it, and learn more quickly and run away? And these are the questions that we are asking.

Dr. Joy: Okay, so I'm glad you explained those because I was like, what's actually happening with the mice? You have the smell, you then do the shock – on the lead mice, I guess? (That is not my world!) Then do they become averse to the smell? Is that what's happening?

Dr. Marlin: Ah, that's a really good question. Based on our preliminary observations, our preliminary data, we don't see that the animals are averse to the odor in the experiment that we're doing. So you have an odor paired with the light foot shock for 10 seconds. Odor and then light foot shock, those animals will avoid. They smell the odor, they go the other way. The offspring are born, and it doesn't seem like they are affected by the odor. But the way my student described it, what she said is, look, when I go up to give a talk, I stand on the platform and I stand in front of the stage and I walk confidently on the stage and I present my slides. What you don't know is I'm sweating. Like my hands are shaking, my palms are sweating. So could it be that the mice feel a certain kind of way, and what we see with them going left or right is just too much above the threshold. We don't see the animals avoid, but do they feel anxiety when going in that corner is the question that we're looking into.

Dr. Joy: But their brain structures are definitely changed.

Dr. Marlin One hundred percent. We are consistently seeing that their brain structure, they're inherited with a different brain structure. And they've never experienced the odor, ever. Just the sperm of their dad is the only thing that's giving them this information.

Dr. Joy: You study mice, but what kinds of questions might you have for somebody who was studying humans? What kinds of things might you wonder about humans based on what you have studied in these mice?

Dr. Marlin: All of our work and everything that we do, if it doesn't go back to, not just informing, but like uplifting humanity, it drops down on my list of interests of things that go in the lab. And really it's something that we stand for and everyone who enters the lab knows that. Although we're using rodents as our model organism, it's for the helps of informing humanity. So all of these questions, we can look at the answer of like what can we picture in humans in one of two ways. I'm a neurobiologist, biologist, psychologist, all of these things by training. I will say like a biologist first. We need to understand how mechanisms work before we can apply them to humans ever. Because historically, especially in this country, we've dumped that, and we've used humans and it's caused a lot of damage and a lot of hurt.

So I take a lot of pride in saying that we treat the animals, of course, humanely and we treat the animals with the utmost respect. Everything that the animals go through, my students go through. Every foot shock, my students put their finger on that cage and they get the shock first. They understand the experience in the experiment. But we have to understand these mechanisms first and then through the larger scientific community, through psychologists who read our work, through psychiatrists who read our work and through other biologists who read our work, it grows and it strengthens. And it says, okay, well what does this look like in humans?

So that's really the first matter. We study mice on purpose, it's not because we don't have access to humans, it's because it needs to be done in order to do the work properly and understand properly how humans work. And I would say secondly, what does it mean for humans? We explore the world through our senses. Through smell and through hearing and through taste. And it seems that a lot of these mechanisms are very similar in rodents, especially smell, taste and hearing, the three that we use. Sight's a little bit different – but I also wear glasses, so I feel like I see probably as good as a mouse! But because we use smell to navigate our world and our environment and to like unlock memories and remember things, and they're associated with emotions, we use that as a proxy for mice. And I think it's a pretty solid proxy.

Dr. Joy: Very fascinating. I'm definitely interested in digging more into your work. So in an interview for the Washington Post, you said: "If I take a step back from being a scientist and I'm just a fellow human in society, we see inherited trauma playing out in many instances across the world. It makes sense. Now we need to identify the biology behind this inheritance, which will help us better understand and navigate the stresses of our world today." I feel like you have spoken to a lot of this already, but I wonder if you could say more specifically, like what do we typically inherit from our parents and grandparents through the transgenerational epigenetics?

Dr. Marlin: The beauty, but also the struggle when it comes to studying humans and understanding what we inherit from our parents and our grandparents, is that for some of us (some of us who are blessed enough to have this), we hear about the experience of our parents and our grandparents at the dinner table. It's because we're hearing what they went through and we're hearing their joys and their pains, and we're seeing the way they navigate the world, and we mimic that. Especially as developing humans, we mimic that. So how much of these learning, things that are happening in our brain, coincide with the epigenetics that have been inherited? Versus it's solely being learned and solely being inherited. And really the question of nature versus nurture. Because there's a whole other way of looking at this. If you have a non-genetically associated person, you have an adopted sibling in a household, are their mannerisms similar to yours and your parents? Yeah, of course. They learn that. Are their outlooks on life and culture similar to your parents, your biological parents? Yes, of course, they've learned that. And so there's one of those questions you really wanna take into consideration. Like how much of the inherited parts are also culturally inherited?

Now, when it comes to what is epigenetically inherited, these are the questions that keep us up at night when it comes to medicine and health. And I'm not giving you an answer because we don't have the answer. We've gone left and we've gone right as scientists when it comes to this. But when it comes to certain pathologies that keep on showing themselves in certain populations, it's hard to say that an increase in anxiety is solely because you saw anxious parents at the dinner table. I study a lot of people populations in America, not directly in the lab, but through our studies. One is the Jewish population. Not just those who left during the Holocaust, but even before when they were still placed in ghettos. There's a constant story of anxiety. Now, how much of this is just grandma was anxious versus generations and generations on this genetic disposition is leading to anxiety in the future? It's a question I can't give you an answer to because we don't know yet. But we see it with our eyes and that's really what I mean by that quote. We see it with our eyes and so it's great to give diligence to what we already know as humans.

Dr. Joy: Something that I have always wondered, because you do hear a lot of stories around trauma being passed intergenerationally. I have always thought if trauma can be passed intergenerationally, can joy and humor and all of those "not negative" things? Can those be passed intergenerationally as well?

Dr. Marlin: That's an awesome question, and I'm gonna answer you now as a human and not as a scientist. I do believe they are because as a black American, there's no way that we could be here if it weren't for that. That ability to say, you know what, you've gone through a lot for generations, but also strength is part of something I'm going to teach you, we're going to epigenetically have for survival, and then therefore pass on as part of our being. Does it come with its pluses and minuses, that word strength, that word diligence, that word resilience? Of course, they're triggering at this point, especially after the last few years hearing them. But doesn't mean that there's not a truth in it. And so I personally believe that that's the case. Now, when it comes to what we're studying in the lab, we're really focusing on the traumas first. Because I really hope that joy is passed down, and if love and joy are passed down, great. We have less work to do as scientists. But it's really the traumas that are going to need our brains and our attention and our minds.

Dr. Joy: What, if anything, in our environment can suppress or enhance the way that our genes work?

Dr. Marlin: Ooh, this is an excellent question. It's extremely controversial. If you look it up, you start seeing like, oh gosh, if you eat kale, kale is the answer to everything. It's like, first off, you're eating it raw and I don't even eat it like that, so I don't even know what you're talking about. There's a lot of people out there that will say like yay or nay to inducing or to creating these changes. Certain dispositions, so not for everyone for example, smoking can cause epigenetic changes. But I want that to be clear. Not for everyone. It's not that every person you study who smokes can have epigenetic changes that will lead them to cancer in the future. And that's the beauty of the nature versus the nurture. It's not beautiful to have cancer, of course, that's not what I'm saying. But the fact that not 100% of the people will have this disposition means that we're starting off with something that's natural, and then the nurture part is what's creating these epigenetic changes.

We do know, pretty consistently across the board, that stress leads to epigenetic changes. Now, across the board is exactly what I mean. As in, in all different facets. In metabolism – going back to what I chatted with you about before with diabetes and hypertension – when it comes to reproduction, having stress seems to play a really important role in lack of reproductive health. Sleep hygiene and learning. These are all things that we can put our finger on that change epigenetic markers when it comes to stress. So it's really a big component.

Dr. Joy: Are there things that we should be mindful of? Let's say we do know some things about our grandparents, and if your research is correct and the research people are doing, that we know we may have kind of been genetically predisposed to higher levels of stress or something like that. Are there things that we should be mindful of in our everyday lives?

Dr. Marlin: Yes. And I think the one thing I'm gonna suggest that we're mindful of is that if we are living in inherited trauma and what inherited trauma looks like (like we've been able to demonstrate) is a change in the brain, it does not mean we're broken. Biology wants us to survive. And so if biology changed our brain in a particular way, based on a stressor in the past for us to survive, let's take a second to honor what biology does which makes sure that we survive. Now with that being said, we know that stressors do change epigenetic markers. We don't know what this exactly means. It could be hypervigilance. If we are living in a war-torn, whatever that means, whether it's in our mind, in our household, in our community, or in the world, it may lead to hypervigilance, which may not be great for day to day, but also allows us to survive. So it does not mean we're broken, it means we're optimized in a way that unfortunately the universe is not changing as such.

But also it probably means that we should be delicate with ourselves and take care of ourselves. Because if we're going through and living life with inherited trauma, that potential hypervigilance (maybe because of the brain structural changes that we're seeing which means you'll be hypersensitive to things in the environment) can wear us out. And we know that living in a state of hypervigilance, where a part of our brain body or the HPA, the hypothalamus pituitary adrenal axis, it’s an axis of stress that releases stress hormones in the brain into the body, and the body back to the brain and feedback, can wear us down. It wears down our immunity, it wears down our sleep health. It wears down our metabolics. So we're ready to fight at every corner and survive at every corner, but we also have to be kind to ourselves and say I live constantly ready to fight.

I had to train and force my body to bring it back to a homeostasis by slowing down. And I'm speaking to you, Dr. Joy, not from the pulpit but standing in the crowd with us. Because I know it, but because of culture and because of the way that we are socialized, it's so hard (especially as a woman, as a mom, as a black person) to say I can sit down. I feel very strongly that my job is to do this research so I can help my people and I can help my people of the world and I can help my people of society. And that can be a really big task and I have to remind myself that if I'm not working optimally, I can't help anybody. And sometimes that means just sitting down. So that's my advice. Sit down.

Dr. Joy: Yeah, that's a good one. That's good advice. Important. And we don't always think about it in that way, but it really is important.

More from my conversation with Dr. Marlin after the break.

[BREAK & Dr. Joy's Webby Award CTA]

Dr. Joy: Something else that you spend a lot of time talking about and studying is the relationship between mother and child. Can you talk a little bit about why the bond between mother and child is so

Dr. Marlin: Once again, it's because biology is so beautiful and it wants us to survive. I'm in love with biology. So what I looked into was how the brain changes to make sure our offspring survive. And by the brain and by offspring, I don't just mean a mother takes care of her kids. And I mean that really specifically. Right now, I also wanna be very clear. When I say male and female, I'm talking about mice, I'm not talking about the human population, which I know goes well beyond male and female. I'm talking specifically about sex in mice. But even when it comes to mom mice and dad mice and their brains changing, what I showed was that virgins – these are animals that have never given birth, never mated – they can learn to be excellent caregivers through the addition of this "love drug," some people call it, but a hormone called oxytocin. Which changes the hearing centers of their brain and makes them respond to the sound of a baby crying.

So mothers will hear a baby cry, and even if it's not their baby, they'll go pick it up and take care of it. Mother mice. Whereas virgins, before oxytocin, the first time they hear a baby cry, they won't. They won't pick that baby up, sometimes they'll cannibalize it. And that may not lead to survival. But what we were able to show through our studies is that it's nature and nurture. Because it seems that if you just look at those two situations, virgin mates with a male then gives birth – great mom. What we saw in our observations was that a virgin who lives with a mom, we treat her with oxytocin, the neurons fire with electricity. The hearing centers change with electricity, and they fire differently, and it's as if they're encoded differently. They're getting a different message when the baby cries and it's no longer "attack" or "ignore," it's take care of. It's as if the brain is ready to be a mom, but it needed that learning experience and oxytocin for it to take place.

Dr. Joy: Okay. And do you do any experiments with the male mice with oxytocin? Do we see something different?

Dr. Marlin: Yes, so we do experiments with male mice, and I feel like this always gets me a little bit in trouble. We did experiments with male mice. Do they have oxytocin receptors, which is how the brain works with the oxytocin? Yes. Do they pick up pups? Yes. Virgins will learn to pick up a pup on the order of 12 hours. Males, three to five days. So in the wild, that's not as great, but also there are sex differences in the male and female brain in mice and it could just be that they're optimized for different things. The mother will feed the pups for 21 days, which means it may make more sense for her to have to hear these pups and pick them up because she's gonna be foraging and coming back to the nest, while the dad's gonna be out and about. So biology maybe has optimized these two as well.

Dr. Joy: Got it, got it, okay. So what lessons or questions do you feel like your own motherhood journey have brought up?

Dr. Marlin: Oh goodness. I thought I knew everything about motherhood. I'm like, yeah, I have a whole PhD in this, I've got this. And then I gave birth. But I do think that not only was I blessed enough to be a mom of two kids, but I also had the opportunity for *[inaudible 0:33:17] a foster mom. And this comes from I think via observations. I told you I was interested in education, but I was also interested in how the brain changes because I was blessed enough to grow up in a household where my biological parents were foster parents. And so I was able to speak with my siblings about the lives that they had before they came to my home and what that looked like. And so I think something that's brought from my science to my household and to my heart is really that biology has us set up for survival. Because you don't have to give birth out of your body for biology to set up your brain to take care of an offspring. And to see that, both in the lab but also in practice, just further gives truth and credence... It's what we already know in our heart, but it's good to see it when it comes up as data. So I think that's been the biggest blessing of being able to be a parent. To know that even when I'm not the best, the way I would define the best, I have the groundwork to be good enough, and that's what my kids need sometimes. Good enough, and biology's got me set up for that.

Dr. Joy: Thank you for sharing that. You bring up an interesting thing. When you think about adoptive children and we don't always have the history of our parents or our grandparents. How can we identify or is there a way to identify inherited trauma without the insight from parents or grandparents?

Dr. Marlin: That's an amazing question and it really comes down to how do you interact with the environment, and then being sensitive. Because there may be questions that we can't answer. You don't know your parents, or you may not have information about your parents and therefore your grandparents. And many of us who have our biological parents don't know what happened four generations back. And so being aware of how you interact in different environments and being sensitive to how different environments make you feel. But also knowing that if epigenetic changes can be put on, they can be taken off. Which means that even if you don't know the trauma and trauma that has happened, it could be for the better. It's not something that's replaying, the nurture part that's replaying again in your mind. And if you find that there's sensitivities that you can't put your finger on, you don't know where they came from, being sensitive to being soft in those situations. And maybe for (speaking with a more hand wavy, non-biological term) essentially massaging those epigenetic markers off that part of your genome.

Dr. Joy: What do you mean when you say they can be turned on, they can also be turned off. Because I think there is also the conversation around people being the one in their family to break the generational trauma. And so what do you mean when you say that?

Dr. Marlin: Exactly what you said. Breaking generational curses, breaking generational traumas. We hear this commonly and we feel that in our hearts. Once again, we wanna bring credence to that. When it comes to the science and to the biology, there are many ways that our DNA sits in our body and it allows it to be read or unread – these are epigenetic markers. As well as other things that are floating around in our cells that we're still learning what they are. An example of this is something called long noncoding RNA, which is a part of our cells, but we don't really know how it's working to change the rest of everything and it can increase or decrease the response to trauma, etc. What does it mean to be turned on and off? What it means to be turned on and off is that we can add epigenetic markers. And in a lab, we can go and we can blast these epigenetic markers on and off. We can inject drugs and they put these epigenetic markers on and off.

But because there's a mechanism that has put them on in the environment… For example, if you put on a lot of weight during the winter, which sometimes happens, it changes some of the epigenetic markers in your body. And then when you lose weight in the summer, it changes some of those epigenetic markers in your body. They're not permanent, is what we're saying. Now, how to target the ones that are particular to stress as opposed to metabolics which is something I'm talking about right now, that's the question. How do we say, you know what, looking a little thick in the winter is not the issue that we're trying to focus on. We're trying to focus on the anxiety I feel walking into this room, and how do I change that if that is inherited epigenetically? And that's one of the questions we look to answer. Targeting.

Dr. Joy: Got it. Yeah, and as a psychologist I feel like there's a lot of research that talks about therapy and different kinds of things that therapists and practitioners do to help massage, as you mentioned, on the epigenetics. So I appreciate you sharing this. I think I thought that they were permanent, but you're saying they're not. The markers are not permanent.

Dr. Marlin: And I have to thank you from the bottom of my heart because I found my therapist through you. On the website. So I'm not just massaging stuff off that I do on the genome. That's there, but also preventing and preparing for future stressors that are 100% going to come. I'm a human on this earth, the stressors are going to come. But finding ways to adapt in response to them, even something as simple as the way you respond in a stressful situation, can change those epigenetic markers or prevent them from even going on.

Dr. Joy: As I'm listening to you talking, as a fellow parent, I think a lot of us are thinking about, okay, how do I not pass this on to my child or my grandchildren?

Dr. Marlin: Gosh, every day. I'm talking to you, but I'm talking to myself. Like Bianca, it's fine. You're fine. You're gonna be massaged off. My kids are black and Jewish, it's like, o gosh, y'all.

Dr. Joy: What advice would you give to fellow parents or caregivers who don't want to pass on any generational trauma? Like what kinds of things should they be mindful of, or what kinds of practices may they want to engage?

Dr. Marlin: If you're a parent right now, it means that your kid is there, it's born. So we're not talking about the genetics. You're staring at it, it's staring at you. But when it comes to your epigenetics, I think one important thing we can teach our kids… and by teach I really mean demonstrate because not everyone's going to be out there, is going to be a child psychologist or have the time or the bandwidth to practice these things. But in modeling how we navigate certain situations and modeling what stress looks like and modeling what taking care of yourself looks like and modeling what sleep hygiene looks like and modeling what… We could use the word self-care, but self-care is world care. It's like societal world care looks like. We could be priming our little ones not to take on epigenetic markers of stress that aren't beneficial to them because they're able to navigate these situations. And even doing a little bit of the massaging, because as they start to take care of themselves, as they start to honor the parts that are not going to heighten that anxiety when it's unnecessary, those can be the steps taken.

And you can sit yourself in a spiral of, whoa, this happened to me and then I decided to give birth, am I wrong for doing that? Should I not have passed these things on? People have been giving birth since the beginning of time. We're not gonna stop giving birth. So I just hope that what our work shows is that you shouldn't be afraid of taking these steps. You shouldn't be afraid of giving birth, you shouldn't be afraid of what you can pass down as much as how you can prevent anything going further. And that's something we can do in the here and now and that's the nurture part. We can't control the nature, but we can control the nurture. And no, there's no pill you can take, it's not gonna happen with more kale, but it can happen with things like therapy, like working through your emotions, like modeling healthy emotional responses. And keeping stress at a level that is low when it needs to be. And not ignoring stress, because stress is also adaptive and sometimes needs to be high. It just doesn't need to be high all the time.

Dr. Joy: Dr. Marlin, where can people stay connected with you and all of the incredible work that you're doing? What is your website as well as any social media handles you'd like to share?

Dr. Marlin: Oh, yes, thank you. Thanks for asking. I'm looking forward to sharing all the exciting work coming out of the lab. My lab website is And on Twitter, I'm @BJMarlin. As well as Instagram, @BiancaJonesMarlin.

Dr. Joy: Perfect. We'll be sure to include all of those in the show notes. Thank you so much for sharing with us today, Dr. Marlin.

Dr. Marlin: Thank you so much for having me, Dr. Joy.

Dr. Joy: I'm so glad Dr. Marlin was able to share her expertise with us today. To learn more about her and her work, visit the show notes at And don't forget to text two of your girls and tell them to check out the episode as well. If you're looking for a therapist in your area, check out our therapist directory at

And if you want to continue digging into this topic or just be in community with other sisters, come on over and join us in the Sister Circle. It's our cozy corner of the internet designed just for black women. You can join us at This episode was produced by Fredia Lucas and Ellice Ellis, and editing was done by Dennison Bradford. Thank y'all so much for joining me again this week. I look forward to continuing this conversation with you all real soon. Take good care.


Discover the transformative power of healing in community in Dr. Joy Harden Bradford’s debut book, Sisterhood Heals. Order your copy now!

Sisterhood heals
Order Now

Looking for the UK Edition?
Order here

Discover the transformative power of healing in community in Dr. Joy Harden Bradford’s debut book, Sisterhood Heals. Order your copy now!

Looking for the UK Edition? Order here