Comment by Aurornis
5 hours ago
Those are articles about maternal stress during pregnancy.
The trans-generational epigenetic inheritance proponents claim that trauma can induce lasting generational effects spanning multiple levels of descendants, even if it doesn’t occur during to the mother during pregnancy.
The paper this HN submission is talking about claims to have found an effect like this that persists for 4 generations.
A key problem with the inter generational trauma proponents is that they presume the effects will only be negative. However, studies like this one showed a positive adaptation. Evolutionarily, it would make more sense if epigenetic mechanisms generally conferred benefits and learned adaptations, which goes against the narratives that anything negative would produce lasting negative effects. It’s not entirely that simple, but it reveals why the intergenerational trauma equals epigenetic inheritance people are starting with a conclusion and trying to get the science to fit their narrative, which is backward from how it should be.
I agree with you there's a lot hand-wavy jumping to conclusions and claims human effects often feel like pop pseudo-science. However I do think when folks imply that epigenetic effects are negative they tend to point towards things like anxiety and fear. Anxiety very well could have a protective evolutionary benefit if you assume the next generation will also be born in a high-risk environment, but a generation later these qualities would be perceived as a negative consequence.
Another example is famine, it may be advantegous to store visceral fat in a low food environment, but if the famine ends, the next generation is more likely to carry this "advantage" which is now negative: https://www.sciencedirect.com/science/article/pii/S216183132...
I suppose one would have to follow the cohort and see if the epigenetic changes observed so far carry over into their own children. I do find it interesting that stress in the mother becomes higher BMI in the offspring. It makes sense if you're talking about animals trying to survive in a harsh environment.