I went down a rabbit hole about this while reading The Telomere Effect (recommended reading). The book goes into the good stress vs. bad stress paradigm and how it has a biological basis - literally at the RNA level. There’s a Goldilocks zone where, for example, the right amount of good stress actually increases your lifespan, and the lack thereof is actually bad for you. Of course bad stress is bad in any amount, with bigger consequences if you’re younger or, get this, in the womb. If a pregnant woman experiences a traumatic event or bad or chronic stress, that can result in lifelong issues for the kid. I don’t recall if the book went beyond RNA and into the neuroscience aspect or whether that was from further reading, but the neurological effects are significant too.

Update:

Harvard Medical School article: Understanding the stress response https://www.health.harvard.edu/staying-healthy/understanding...

Research on effect on neural circuits: https://jneurodevdisorders.biomedcentral.com/articles/10.118...

Harvard article on impact of early childhood adversity, including on brain: https://developingchild.harvard.edu/resources/inbrief-the-im...

All of this is talking about physiological changes, which are well known, not gene expression. Gene expression is entirely different than the repercussions of psychological trauma.

See the following study in Nature and scroll down to “Epigenetic reprogramming by ELS: the current landscape” -it gives an overview with citations and links included:https://www.nature.com/articles/s41398-022-02076-9

Telomere Effect also goes into epigenetic changes but isn’t solely focused on stress

Do I get to count as evidence? The stress they're talking about is clearly defined. It's ACE levels.

Before the age of 5 I was hospitalized for falling out of a moving truck and had an ace score of 9, after adoption at 5 I had an ace score of 6-7. I was regularly beaten over the head, yelled at, had food withheld--the whole 9 yards. Almost always related to academic performance because I already had ADHD and PTSD from before adoption.

I now am starting to realize that beyond being easily triggered due to PTSD, I can ONLY function cognitively if I am under stress. It's taken me a long time to figure out if what I'm dealing with is ADHD, PTSD, dissociation, or what--it's hard to pin down. I finally realized that I perform, socialize, play, create and cooperate better if I am angry, scared, worried I'll get fired, or various other social pressures that make people panic. I am useless otherwise. I have come to the conclusion that I am adrenaline deficient because my brain developed in a wash of adrenaline and learned to stay there.

In social situations I come across as aloof or disinterested, absent, withdrawn, and when I'm excited about something or seeking socialization I come across as confrontational, argumentative, or upset when I'm happy and joking. I mostly don't see a point in socializing when I am not perceived according to my internal experience.

The only time I've ever been normal and functional is the 6 months after my mom died, a time when most people are incapacitated due to the stress of grief.

I gotta say as an N=1, having early childhood stressors and head trauma have not exactly made me more pro-social, creative, cooperative, etc. To get that Optimal level of stress requires that I destroy my body with cortisol.

I'm sorry for the ordeals you've gone through in your life, but gene expression is entirely different than psychological trauma.

It’s not different, the two are tied. See my comments above, including my response to you related to epigenetic changes from stress.

The person you are responding to likely has notable epigenetic modifications that have lasted way past the initial negative environmental stimuli (in proportion to the trauma). It’s not a hopeless situation, there is literature on how to reverse and mitigate that, but it’s important to be aware of.

No. There's no proof that the gene activation differences that occur are negative. There's no proof that the gene activation differences are the cause of the psychological and behavioral differences seen by victims of trauma.

If you're old enough to be here, you've already seen all the evidence you need.

And not just humans. Pretty easy to tell if an animal has been mistreated. Kittens raised on the street, where they compete with each other for food, are nothing like those born and raised indoors.

Do you really need "hard science" for this kind of stuff?

I don't think it's unreasonable to ask for "hard science" on this. Just as you've provided an anecdote of "street kittens," I have personal anecdotes of children who grew up in abusive families who turned out to be very nice people. Of course, there may have been less visible setbacks in other parts of their development, but at the end of the day it's not a clear-and-cut A causes B to me.

You are right. It's not unreasonable to ask, however it wouldn't hurt to demonstrate some basic acknowledgement that things do seem to be strongly correlated. Even the biggest idiots understand the concept.

You are also right that not everyone (human or different animal) reacts the same. Some turn the other cheek, some will break your nose. The scars will always be there, though.

I've never seen any evidence that changes in gene expression are mostly negative. The entire point is gene expression, not that stress or trauma causes a person to behave differently afterwards. It's weird that people on this thread don't seem to understand this very important distinction.