What they found was that the mice with very specific defects of mitochondrial energy production experienced profound deleterious effects from the level of the cell all the way through to the entire organism. Their organs, their axes, and the entire mouse failed to adapt to the insult of restraint stress if the right defect in energy production was introduced. Some were more deleterious than others, but the overall point stands: if you can’t produce energy under stress, whether it’s psychological or physical materialist in its nature, you fail to adapt down to the level of your lived biology.
In my speculations, though this hasn’t been shown to be the case in humans yet, there is no reason to suspect that our own responses to psychological stress aren’t mitigated in the same or similar ways, and modern life in bureaucratic, systematic civilizations is one long constant stressor of domination that strips people of their autonomy. I think on a near societal scale we are experiencing learned helplessness from chronic psychological stress, and the people who have successfully evaded state control to self-determine their circumstances not only have a desire to do so, they also have real, material, physiological advantages, if the story I’ve woven together makes sense.