Mh, trauma effect can be transmitted simply by education by parents, for instance if a parent have had a trauma with fire they can act with fear of fire and it's children simply absorb that fear observing. I do not know how this can became "genetic" but I think also something may pass during pregnancy in a way we can call "instinct" in absence of better explanations...
The “better explanations” are called epigenetics. Environmental factors can cause genes to be turned off or on and that in turn can be passed to children. So the environment doesn’t effect your DNA (Lamarckian evolution) but it can still cause your offspring to act differently.
Translating a bit for people coming at this from a CS background: epigenetics is the recognition that cell division (eiher mitosis or meiosis) is way more like fork(2) than exec(2). There's tons of current mutable state maintained across the division in addition to the more or less fixed executable (DNA).
Epigenetics is fascinating because methylation is a basic read/write layer on top of static DNA - changes can appear in a living organism and propogate to offspring.
> Even short-term substance abuse can produce long-lasting epigenetic changes in the brain of rodents, via DNA methylation and histone modification.
> Environmental factors can cause genes to be turned off or on
The principle here is straight forward, but it's not clear to me that anybody has actually demonstrated a clear 'signal' in the process.
In other words there is evidence that stress caused by fire trauma can change the way genes are expressed in an individual, and I believe there is evidence that stress from trauma can impact gene expression at the process of genetic recombination. However I've not seen any evidence that, for instance, stress caused by fire will induce any sort of specifically fire related gene expression in offspring. Would an orphan who never knew their parents have an elevated fear of fire if both their parents had survived a severely traumatic experience with fire? To my knowledge, that's still purely speculative.
The closest I've seen is the suggestion that offspring of famine survivors may have an epigentic change that makes them gain weight:
>The field of epigenetics gained momentum about a decade ago, when scientists reported that children who were exposed in the womb to the Dutch Hunger Winter, a period of famine toward the end of World War II, carried a particular chemical mark, or epigenetic signature, on one of their genes. The researchers later linked that finding to differences in the children’s health later in life, including higher-than-average body mass.
But that leaves open many questions. What other epigentic changes did these people have that seem unrelated to food/weight? And how many people who suffered from trauma unrelated to food availability have changes that effect weight gain?
The Dutch children are an odd example here, because they themselves experienced hunger in the womb. That their bodies remember this isn't surprising at all. The markers through which this is remembered are sometimes called epigenetic, the word seems to be a little fuzzy... I guess there is a small step between individual cells having persistent changes, and daughter cells in the same individual inheriting such changes. (But again unsurprising: the embryo needs to mark some cells as future-leg-material when it's only a few hundred cells, and their millions of actual-leg-cell descendants remember.)
The big and controversial step is to writing such changes into the germ-line, so that offspring of the individual cary such a memory. And my understanding is like yours, that there's some evidence for crude things (like massively stressed / starved mice having offspring who are calibrated a bit differently) but not really anything solid for the sort of finer changes we like to speculate about in humans.
It's not impossible, and it need not be un-Darwinian: your genes care more about how many grandkids you have than how many kids, and if pre-adjusting your kids to the environment is advantageous, then they certainly have the motive to do it. And there are corners of biology in which you could hide a mechanism to do this (just a little bit) where we would not yet have seen it.
But a lot of the tantalising studies seem to underplay ordinary inheritance. For example, lots of abused children, sadly, have a 1st-degree relative who abuses children. Some of whatever is wrong with the abuser may also be wrong with the victim (through no fault of anyone's!) and this may show up on all sorts of measures. Removing such things from your data is going to be super-hard, and if you succeed, you are more likely to get a boring paper.
>"The Dutch children are an odd example here, because they themselves experienced hunger in the womb. That their bodies remember this isn't surprising at all."
Good point, there's an ocean of difference between experiencing hunger in the womb, and being well nourished in a womb belonging to a woman who was once malnourished.
I don't have that study available to me at the moment to check, but I wonder what they say about children born from those same mothers years after the famine was over. Surely they looked at that too, since if the same signal was present that would certainly enhance their findings. If the study doesn't mention those later children at all, that would suggest to me they're guilty of p-hacking.
I think it is kind of a stretch to call it epigenetics when the mother was traumatized while pregnant with the child in question. I think we need a different concept for that.
But I can well imagine that, in most cases, trauma leaves a body permanently altered in some manner and that this can potentially impact later children.
With no real scientific basis to back it up, I will suggest that if trauma is passed on to the children biologically, the degree and manner of the inheritance may vary depending upon whether the traumatized parent was the father or the mother. Logically, the fact that the biological mother (in "old fashioned" pregnancies) both contributes DNA and also serves as the incubator for the fist nine months of life, whereas the father only contributes DNA, should make a difference in how heritable such a thing is.
That makes sense, if there is any measurable effect on children who's fathers but not mothers have suffered trauma such as starvation, that would be a compelling result.
I wonder how much of the change could be explained by a change in the gut flora/fauna that was passed on to the Dutch children due to their parents' starvation.
This would also be interesting. But has the same difficulties, of looking for the effect of an exotic process, when we know that quite normal processes are also involved.
I don't know whether anyone has looked at this in mice, I mean in the torture-the-parents experiments which they do to look for epigenetic inheritance.
I agree, (mis)education is one way how we inherit trauma.
Being a parent is something generally learned from your parents (based on how you were raised), with maybe a bit of advice from books/tv/friends. A parent with a traumatic past/upbringing can easily bring that into the situation of the present with their raising of their own children, effectively "passing it on" to a new generation. These "lessons" can be very subtle because like many things learned as very young children (a lot of that through mimicry and observing your parents), people tend to take them for granted without question (until something comes up to make you consciously question it).
For example, the people that think it's fine to hit their children or yell at them because "that's what their parents did." Parenting is one of those seemingly crucial skills that is hard to learn, doesn't take a license, everyone is thrown into without practice for their first child, and can radically affect how children grow and develop.
This of course is both personal anecdata, having talked to a lot of people, and reading a fair amount of books on childhood trauma. It's a hard field to get hard scientific research on, since it's not really ethical to do that kind of research on children, but here's a recent paper of interest:
"Parents who lived through adverse childhood experiences were more likely to report higher levels of aggravation as parents and to experience mental health problems, the researchers found. However, these mental health and attitude factors only explained about a quarter of the association to their child's elevated behavioral health risks. The remainder of how the parent's adverse childhood experiences are transmitted to their child's behavior deserves further study."
So maybe epigenetics are one of these other ways things get transmitted. But I think it's a lot easier to study because it's easier to measure than something like childhood experience. Even children can't be expected to remember what really happened.
I had a mentally ill roommate - I can definitely confirm this phenomenon is possible. Especially when a close housemate isn’t willing to acknowledge their condition and allows it to progress in severity.
I'm not an expert, but it seems like this article might be blowing up a specific controversy into a general doubt about epigenetics. The stuff I've read talks about how during pregnancy, the mother transmits information about the environment to the fetus which causes epigenetic shifts. And this can compound generationally. The critical statements in this article appear to be specifically about epigenetic transmission via sperm, which I hadn't read about having strong evidence to back it up.
I don't believe it. I would have to conduct this experiment myself and see the actual reaction with my own eyes to believe it. I cannot imagine that knowledge about a smell is passed down to a descendant. Or have an explanation for the mechanism by which this happens. Why does this happen, how is the information transferred? It makes no sense.
Your ability to recognise faces, you surely realise, was passed down to you genetically? It’s encoded as hardware priors in the structure of your brain. So it’s not too hard to extend that to knowledge of a smell, similarly hardcoded somewhere. I’m not defending the original paper btw, which seems to have some faults.
I'm greatly disturbed that no one seems to have tried to replicate the experiment of huge significance since 2013. Or worse people use it as a fact, without it having been replicated.
Science has some real fundamental issues atm.
Wiki points out some issues, but it seems simple to me, it needs to be replicated.
"Several criticisms were reported, including the study's low statistical power as evidence of some irregularity such as bias in reporting results.[91] Due to limits of sample size, there is a probability that an effect will not be demonstrated to within statistical significance even if it exists. The criticism suggested that the probability that all the experiments reported would show positive results if an identical protocol was followed, assuming the claimed effects exist, is merely 0.4%. The authors also did not indicate which mice were siblings, and treated all of the mice as statistically independent.[92] The original researchers pointed out negative results in the paper's appendix that the criticism omitted in its calculations, and undertook to track which mice were siblings in the future.["
People say this, but it seems pointlessly dismissive to me. I'll entertain any claim, regardless of evidence. Extraordinary claims are often the most worthy of entertaining.
My brain has no problem keeping track of speculation, provisional theories, and seeming facts. I don't have any trouble storing both "seems plausible" and "has evidence" notions side by side and juggling them accordingly.
That aside, my general assumption about evolution is that, since there's no requirement for adaptations to "make sense" and they have access to all of reality, including everything science has yet to deconstruct, that animals almost certainly rely on adaptations far beyond scientific understanding. So a claim to that effect isn't that extraordinary anyway.
What constitutes an "extraordinary" level in "extraordinary claims" is one the least-defined things in aphorisms related to science. It reminds me of what some call the "stages of change" First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.
It seems if what is "extraordinarily" unlikely can easily become "true and self-evident" then extraordinary was a more a way of fighting against things opposed for more emotional than evidentiary reasons.
My friend's dad never took responsibilites seriously, so when she was conceived, her mom was very worried/stressed as her dad was contemplating to fly to a different country with some other women forever.
When she was 10, weird depression developed and it still affects her to this date.
She isn't poor, he mom has a good job.
But is it possible the perception of environment from her mother, transfered to womb and gave her this depression?
Maybe she had depression since birth but only managed to communicate and understand it when she turned 10?
It's within the realm of possibility, but you definitely shouldn't jump to the conclusion that a particular individual's depression is rooted in epigentics because she isn't poor.
> My friends dad's never took responsibilites seriously
What kind of dad was this man then? What kind of connection did he build with his daughter?
It's so obvious from what you wrote, yet it's interesting you seemingly didn't draw the connection. edit: it may be also that your friend herself did not draw this connection or is unconsciously avoiding it.
So, so much happens behind closed doors, in every home. So much unwritten history. So much that you'll never know about someone.
We all want to love our parents and feel it is the right thing to do. Yet to heal trauma, to heal depression... you have to acknowledge the anger that has built up. Legitimate anger of being ignored, insulted, ridiculed, abandoned, shamed, and so on. Paradoxically.. it is through gradually allowing oneself to feel this anger, that the heart opens.. and we are able to love again both self and others.
> What kind of dad was this man then? What kind of connection did he build with his daughter?
I'm not sure whether you intended this, but (since we're discussing biology here) this is really two possible connections. One is that she grew up with a dad who was (apparently) a gigantic asshole. The second is that she got 50% of her genes from a gigantic asshole. Or more charitably, from someone who wasn't emotionally a great fit for 20/21st century capitalist society.
Before any study counts such things as evidence of weird epigenetic effects, it had better do a really solid job of taking these (19th C) effects into account, to see if there is anything left. And that's pretty hard to do.
She told me she doesn't love her dad and she thinks he's immature.
She visits her dad since she went to the country where her dad lives for studies.
She asked her dad for money for her studies but he refused, saying that he doesn't have any.
He also sometimes joins her in shopping and buys stuff for himself and never pays for it.
All while her mom supported her.
But she believes it's because of her, her mom has never progressed in like her dad. (Read: finding a different life partner)
The biggest problem is that she feels as if she's burden for her mom. She tried sucide at 16.
Now she's 18 and doesn't feel sucidal anymore but negative throughts have never left her.
I convinced her to go to a doctor who prescribed her Mirtazapine 15mg. It worked for a few days then stopped working.
Now, she's avoiding doctor.
He depression is very severe. Racing thoughts overload her brain to point where she's not able to think clearly anymore.
Feels tired all time.
All her friends have left her without saying anything.
Only i am left now. I don't like seeing her like this.
I've read a lot about depression so, that i don't end up making it worse and not hurt her in anyway.
She says, stop trying for me, I'll never be cured.
But I've a strong belief to see her cured one day.
If she can afford it talk therapy is what she would really benefit from. Unfortunately talk therapy is expensive.
You can NOT change her. She will reach out eventually, or she won't. Believing "I'll never be cured" is itself a defense mechanism. That can mean she's just too young to be able to start healing. Particularly if she's still stuck in this environment, and living with those dependencies. Only when she's able to fly out of the nest, and distance herself sufficiently from both her parents, she can begin opening up.
The next best thing to help her cope till someday she find the strength to reach out, is a yoga class. That is not so expensive, even just once a week will do wonders and more effective and soothing than taking antidepressants. I talk from experience from a time when I had insane levels of anxiety. Just once a week made a significant difference.
Bless you both not much else I can say. I wanted to type more but it's too complex of a topic.
Epigenetics is largely bullshit, wishful thinking, and p-hacking. Get enough scientists who want something to be true, and you'll get a few supporting results that can't really be replicated.
The article mentions Mosche Szyf at McGill. Michael Meaney[0], also at McGill, is one of the main investigators in this area. IIRC, mice studies are convincing, in as much as the exact molecular mechanism for epigenetic transmission was tested in crossover studies. “Environmental conditions during early development shape brain development. The Meaney lab idenfitied phenotypic variations in rodent models that derive from variations in maternal care. Maternal care stably modifies the epigenetic state and expression of genes implicated in behavioural and endocrine responses to stress and learning. These studies were the first to describe the influence of the social environment on genomic structure and function.”
Although the study 'supports' epigenetics it seems obvious there are other possibilities as well. Abuse effects people mentally. Those effects can be passed on to kids behaviorally.
39 comments
[ 298 ms ] story [ 3686 ms ] thread> Even short-term substance abuse can produce long-lasting epigenetic changes in the brain of rodents, via DNA methylation and histone modification.
https://en.m.wikipedia.org/wiki/Behavioral_epigenetics
The principle here is straight forward, but it's not clear to me that anybody has actually demonstrated a clear 'signal' in the process.
In other words there is evidence that stress caused by fire trauma can change the way genes are expressed in an individual, and I believe there is evidence that stress from trauma can impact gene expression at the process of genetic recombination. However I've not seen any evidence that, for instance, stress caused by fire will induce any sort of specifically fire related gene expression in offspring. Would an orphan who never knew their parents have an elevated fear of fire if both their parents had survived a severely traumatic experience with fire? To my knowledge, that's still purely speculative.
The closest I've seen is the suggestion that offspring of famine survivors may have an epigentic change that makes them gain weight:
>The field of epigenetics gained momentum about a decade ago, when scientists reported that children who were exposed in the womb to the Dutch Hunger Winter, a period of famine toward the end of World War II, carried a particular chemical mark, or epigenetic signature, on one of their genes. The researchers later linked that finding to differences in the children’s health later in life, including higher-than-average body mass.
But that leaves open many questions. What other epigentic changes did these people have that seem unrelated to food/weight? And how many people who suffered from trauma unrelated to food availability have changes that effect weight gain?
The big and controversial step is to writing such changes into the germ-line, so that offspring of the individual cary such a memory. And my understanding is like yours, that there's some evidence for crude things (like massively stressed / starved mice having offspring who are calibrated a bit differently) but not really anything solid for the sort of finer changes we like to speculate about in humans.
It's not impossible, and it need not be un-Darwinian: your genes care more about how many grandkids you have than how many kids, and if pre-adjusting your kids to the environment is advantageous, then they certainly have the motive to do it. And there are corners of biology in which you could hide a mechanism to do this (just a little bit) where we would not yet have seen it.
But a lot of the tantalising studies seem to underplay ordinary inheritance. For example, lots of abused children, sadly, have a 1st-degree relative who abuses children. Some of whatever is wrong with the abuser may also be wrong with the victim (through no fault of anyone's!) and this may show up on all sorts of measures. Removing such things from your data is going to be super-hard, and if you succeed, you are more likely to get a boring paper.
Good point, there's an ocean of difference between experiencing hunger in the womb, and being well nourished in a womb belonging to a woman who was once malnourished.
I don't have that study available to me at the moment to check, but I wonder what they say about children born from those same mothers years after the famine was over. Surely they looked at that too, since if the same signal was present that would certainly enhance their findings. If the study doesn't mention those later children at all, that would suggest to me they're guilty of p-hacking.
But I can well imagine that, in most cases, trauma leaves a body permanently altered in some manner and that this can potentially impact later children.
With no real scientific basis to back it up, I will suggest that if trauma is passed on to the children biologically, the degree and manner of the inheritance may vary depending upon whether the traumatized parent was the father or the mother. Logically, the fact that the biological mother (in "old fashioned" pregnancies) both contributes DNA and also serves as the incubator for the fist nine months of life, whereas the father only contributes DNA, should make a difference in how heritable such a thing is.
I don't know whether anyone has looked at this in mice, I mean in the torture-the-parents experiments which they do to look for epigenetic inheritance.
Being a parent is something generally learned from your parents (based on how you were raised), with maybe a bit of advice from books/tv/friends. A parent with a traumatic past/upbringing can easily bring that into the situation of the present with their raising of their own children, effectively "passing it on" to a new generation. These "lessons" can be very subtle because like many things learned as very young children (a lot of that through mimicry and observing your parents), people tend to take them for granted without question (until something comes up to make you consciously question it).
For example, the people that think it's fine to hit their children or yell at them because "that's what their parents did." Parenting is one of those seemingly crucial skills that is hard to learn, doesn't take a license, everyone is thrown into without practice for their first child, and can radically affect how children grow and develop.
This of course is both personal anecdata, having talked to a lot of people, and reading a fair amount of books on childhood trauma. It's a hard field to get hard scientific research on, since it's not really ethical to do that kind of research on children, but here's a recent paper of interest:
https://www.sciencedaily.com/releases/2018/07/180709101155.h...
"Parents who lived through adverse childhood experiences were more likely to report higher levels of aggravation as parents and to experience mental health problems, the researchers found. However, these mental health and attitude factors only explained about a quarter of the association to their child's elevated behavioral health risks. The remainder of how the parent's adverse childhood experiences are transmitted to their child's behavior deserves further study."
So maybe epigenetics are one of these other ways things get transmitted. But I think it's a lot easier to study because it's easier to measure than something like childhood experience. Even children can't be expected to remember what really happened.
I'm greatly disturbed that no one seems to have tried to replicate the experiment of huge significance since 2013. Or worse people use it as a fact, without it having been replicated.
Science has some real fundamental issues atm.
Wiki points out some issues, but it seems simple to me, it needs to be replicated.
"Several criticisms were reported, including the study's low statistical power as evidence of some irregularity such as bias in reporting results.[91] Due to limits of sample size, there is a probability that an effect will not be demonstrated to within statistical significance even if it exists. The criticism suggested that the probability that all the experiments reported would show positive results if an identical protocol was followed, assuming the claimed effects exist, is merely 0.4%. The authors also did not indicate which mice were siblings, and treated all of the mice as statistically independent.[92] The original researchers pointed out negative results in the paper's appendix that the criticism omitted in its calculations, and undertook to track which mice were siblings in the future.["
People say this, but it seems pointlessly dismissive to me. I'll entertain any claim, regardless of evidence. Extraordinary claims are often the most worthy of entertaining.
My brain has no problem keeping track of speculation, provisional theories, and seeming facts. I don't have any trouble storing both "seems plausible" and "has evidence" notions side by side and juggling them accordingly.
That aside, my general assumption about evolution is that, since there's no requirement for adaptations to "make sense" and they have access to all of reality, including everything science has yet to deconstruct, that animals almost certainly rely on adaptations far beyond scientific understanding. So a claim to that effect isn't that extraordinary anyway.
It seems if what is "extraordinarily" unlikely can easily become "true and self-evident" then extraordinary was a more a way of fighting against things opposed for more emotional than evidentiary reasons.
When she was 10, weird depression developed and it still affects her to this date.
She isn't poor, he mom has a good job.
But is it possible the perception of environment from her mother, transfered to womb and gave her this depression?
Maybe she had depression since birth but only managed to communicate and understand it when she turned 10?
What kind of dad was this man then? What kind of connection did he build with his daughter?
It's so obvious from what you wrote, yet it's interesting you seemingly didn't draw the connection. edit: it may be also that your friend herself did not draw this connection or is unconsciously avoiding it.
So, so much happens behind closed doors, in every home. So much unwritten history. So much that you'll never know about someone.
We all want to love our parents and feel it is the right thing to do. Yet to heal trauma, to heal depression... you have to acknowledge the anger that has built up. Legitimate anger of being ignored, insulted, ridiculed, abandoned, shamed, and so on. Paradoxically.. it is through gradually allowing oneself to feel this anger, that the heart opens.. and we are able to love again both self and others.
I'm not sure whether you intended this, but (since we're discussing biology here) this is really two possible connections. One is that she grew up with a dad who was (apparently) a gigantic asshole. The second is that she got 50% of her genes from a gigantic asshole. Or more charitably, from someone who wasn't emotionally a great fit for 20/21st century capitalist society.
Before any study counts such things as evidence of weird epigenetic effects, it had better do a really solid job of taking these (19th C) effects into account, to see if there is anything left. And that's pretty hard to do.
She visits her dad since she went to the country where her dad lives for studies.
She asked her dad for money for her studies but he refused, saying that he doesn't have any.
He also sometimes joins her in shopping and buys stuff for himself and never pays for it.
All while her mom supported her. But she believes it's because of her, her mom has never progressed in like her dad. (Read: finding a different life partner)
The biggest problem is that she feels as if she's burden for her mom. She tried sucide at 16.
Now she's 18 and doesn't feel sucidal anymore but negative throughts have never left her.
I convinced her to go to a doctor who prescribed her Mirtazapine 15mg. It worked for a few days then stopped working.
Now, she's avoiding doctor.
He depression is very severe. Racing thoughts overload her brain to point where she's not able to think clearly anymore.
Feels tired all time.
All her friends have left her without saying anything.
Only i am left now. I don't like seeing her like this.
I've read a lot about depression so, that i don't end up making it worse and not hurt her in anyway.
She says, stop trying for me, I'll never be cured.
But I've a strong belief to see her cured one day.
I wonder what can i do from here.
It's a decade of depression.
You can NOT change her. She will reach out eventually, or she won't. Believing "I'll never be cured" is itself a defense mechanism. That can mean she's just too young to be able to start healing. Particularly if she's still stuck in this environment, and living with those dependencies. Only when she's able to fly out of the nest, and distance herself sufficiently from both her parents, she can begin opening up.
The next best thing to help her cope till someday she find the strength to reach out, is a yoga class. That is not so expensive, even just once a week will do wonders and more effective and soothing than taking antidepressants. I talk from experience from a time when I had insane levels of anxiety. Just once a week made a significant difference.
Bless you both not much else I can say. I wanted to type more but it's too complex of a topic.
[0] https://douglas.research.mcgill.ca/michael-meaney
Of course.