I don't think the activism/sociological angle here was supposed to be interpreted as being about targeted reconciliation toward existing victims of violence / their descendants. Even if those people are potentially "living life on hard mode" as a result of previous violence. (After all, finding and helping those people would require complex infrastructure and lots of money.)

Rather, I think the thrust of the implicit activist argument would be closer to:

1. Experiencing violence turns out to be even worse for you than we thought — and in non-recoverable ways! (You can't therapy your way out of epigenetic changes.)

2. And so more should be done to prevent/ameliorate violence and its impact on people, before it can cause durable epigenetic changes;

3. ...and some "low-hanging fruit" in reducing this impact for minimal cost, would be to supply more resources (e.g. shelters; crisis lines; social workers; restraining orders that actually work) specifically to groups who are demographically most likely to become victims of violence.

4. And maybe we can even use this correlational data to measure interventions like these, sampling the epigenomic changes in these vulnerable populations over time (repeated cross-sectional study), to know if marginal increases in certain types of resources actually have measurable impacts on "cushioning" these populations from violence, enough to prevent these epigenetic changes.

Use this (faulty) explanation to make a statement about the impact of violence -> direct resources to one demographic or another based on that (faulty) explanation of why it's important.

Your fourth point is entirely valid, if we were performing these measurements & experiments at a large enough scale to have a valid baseline in the first place (which GP was arguing is not the case).

Incorrect. The parent comment was talking about using epigenetic measurements of specific people to decide if they get resources. The child comment was not talking about doing that, instead saying that this research can be used to argue for more resources in general.

The only mention of demographics in the child comment was about groups likely to experience violence. Those groups would have no markers. It would be purely about how we can most effectively reduce violence.

The only measurements suggested in the child comment would be for statistical purposes.

If you want to direct resources to groups "likely to experience violence" based on other statistics anyway, then you don't need this type of research to do it. And if you're going to use this type of research in support of that, then it is just as important that it's accurate as it would be if you were using it at an individual level.

The parent comment called out "puny sample sizes." That would be relevant to the "statistical purposes" suggested by the child comment.

It's bad in a very different way, with a different level of impact. And there are ethical issues with that kind of use even if the research is right which don't exist with the broad statements they were suggesting.

> If you want to direct resources to groups "likely to experience violence" based on other statistics anyway, then you don't need this type of research to do it.

You do if you're trying to convince people to allocate the money, because longer lasting damage makes it more important.

> And if you're going to use this type of research in support of that, then it is just as important that it's accurate as it would be if you were using it at an individual level.

It's not. The consequences of screwing up individual diagnoses are much worse than the consequences of a funding campaign having a false premise.

Isn't that exactly what the study purports to show? Why would psychological trauma (i.e. negative nurturing) effect epigenetics but not psychological healing (i.e. positive nurturing)? What we consider "trauma" by modern standards would have been experienced by a huge fraction of every prior generation, and over the course of generations the entire population countless times over via epigenetic inheritance. Either it works both ways, even if unevenly, or it's BS (the framing if not the science). Ideological motivations aside, it just happens to be much easier to identify and track discrete incidences of severe trauma.

Yes, you can cushion people from the effect of trauma as it's happening, by providing resources at or soon after the point of trauma.

But your epigenome is a record (almost exclusively) of stuff that was observed during your development — it's a log, not a state database.

A particular epigenome-affecting gene process would look like: "when I was -6 months old, a process kicked off that began expressing a gene. This gene caused the expression of a protein that acted to detect whether there was enough magnesium in my blood or not. It detected that there was enough — and so the protein recorded [by not methylating anything] that I shouldn't silence any of the copies of the magnesium-transporter in my intestinal-lining tissue cells. Then, the buildup of the protein caused the expression of another gene, which methylated [silenced] the first gene, permanently deactivating this magnesium detection step from happening again."

Which means that trauma during early development — if it is not cushioned at the time, such that its impact is felt fully* — will lead to some epigenome-affecting process that looks for "impact of trauma" observing said trauma as happening at the time it activates, and so recording it. That record, within the cell-line descending from the cell that made that observation, is now permanent; that tissue will now do whatever it does with that knowledge, from then on, for the rest of the organism's life.

Treating the trauma later, will help the organism psychologically, but will not change those markers (and whatever biological effects they have), because they are markers of "what was at a certain point", not "what is."

That's a leap. After all, emotionally distressing experiences presumably caused the epigenetic changes to begin with, so why couldn't other mental experiences alleviate them? Not that we know how to do this at this point, I'm just stating that your claim is not a fact.

Crucially, because these "setup programs" silence themselves after running, these "setup programs" each only have one opportunity to run, at some genetically-defined point in an organism's lifecycle. The information is only collected once. Whatever this "setup program" observed at that point, that's what the epigenome records. There is no second chance to set it differently.

I don't know much about this violence finding, but one famous finding in epigenetics is that mammals whose mothers were often food-deprived during gestation, end up with a marker that correlates with the phenotype of eating more / being more food-motivated / tending more toward gathering more food than is necessary for their immediate satiation.

At least in the case of this food-deprivation finding, there is nothing you can do to/with the animal afterward, that reverses the impact of this epigenetic change. The animal's body doesn't go back and re-evaluate whether or not it "should" be more food-motivated, because the fact it's basing its food-motivation calculations off isn't about what's true now — it's about what was true then. The marker doesn't mean "the environment is currently food-poor", it means "the environment was food-poor when I was -6mo old."

(In fact, these early-natal-development epigenetic markers aren't even necessarily what you might call runtime flags — they're more like an #IFDEF statement in the DNA "codebase", their values first calculated during the long, continuous "build process" of development, and then macro-expanded later in that same build process to hard-code other things — e.g. how certain proteins/tissues and their chemical receptors get built. By the time a baby is born, that marker might actually have no further relevance, having done all its work and made its downstream impacts during gestation. If we had "epigenetic CRISPR" and turned that marker off in an adult person, doing so would only impact whatever that gene does after development — which might be "nothing.")

I just want to add the obvious addendum again: that we know of. We've tried a few obvious things and that didn't change the behaviour, but that doesn't mean much in something this complex.

The argument that "brains are rewired" or "generations of genetics are harmed" is popular in 'trauma informed' arguments for compensation or government help.

*edit

Anyone downvoting me should go read this study. The number of individuals exposed to the initial dose is in the single digits. There is no attempt to account for confounding variables. No mechanism is known that could account for the proposed effect. The preceding animal study they referenced has been HEAVILY criticized for methodological issues.

If you're speaking from an american perspective, this hand-wringing is unnecessary: we leave our own citizens exposed on the street. If we were capable of making decisions about who deserves xyz in the first place we wouldn't be living in such an obvious shithole to begin with. Maybe we should set our standards much lower if we aim for research to actually benefit humans.