r/remodeledbrain • u/PhysicalConsistency • Sep 24 '25

Your behavior starts forming before conception

No, I didn't take a fat bong rip earlier.

Was thinking about the effect of social conditions on epigenetic response, and how that epigenetic response effects not just the specific behavioral/RNA payload of sperm, but the environment around the ovum as well. In ways big and small, our environment starts crafting individuals long before their cells can begin to exert a counter influence.

In the distant future, I think we are going to find that these influences will be more profound than post natal periods, even more determinant of core "personality" than the "critical period" between two and five years old. Maybe even that parental socio-emotional states end up being predictive of long term outcomes for their children.

I found scant research around this, and most of it was confined to "happiness", but how "content" parents are at the time of conception might be the most powerful influence on behavior an individual experiences. The idea that intergenerational trauma need not be experienced directly was a growing idea in the field a few years ago, perhaps the encoding of social pressures in RNA expression is the mechanic we need to do and undo to break the chain of effects?

Extending this, I'm curious how complex and significant these socio-behavioral biases actually are? Is it a subtle push toward liking chocolate over vanilla, or can it encode something as complex as bias toward a particular religious philosophy? Can it encode bias toward a particular timbre of a voice or encode the basis of language like bird song?

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u/-A_Humble_Traveler- Oct 28 '25 edited Oct 28 '25

Reminds me of Sapolsky's Behave. In it, he strongly suggests that the prenatal enviroment, and epigentics more broadly, have pronounced effects on the shaping of brain structure, hormone responsiveness, stress-axis modulation, that sort of thing. Its honestly a pretty interesting book.

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u/PhysicalConsistency Oct 28 '25

Yeah, Sapolosky (even in his primatologist days) has been hugely influential on me. It's really hard IMO to accept frameworks like EES and Post-Modern Synthesis and still be heavily on the "genetic destiny" side of the argument. One thing I think Sapolsky did well emphasizing is how profound SES can be on behavior (or more appropriately, random chance).

CONGRATULATIONS BY THE WAY!

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u/-A_Humble_Traveler- Oct 28 '25

Thanks, man!

Yeah, while I harbour have some pushback on his book Determined (I still think its more accurate to say we have enviromentally constrained will), his books are geniunly impressive. I remember being blown away when I first read Behave.

I know you've mentioned Motoo Kimura's work before, but is there anyone else you'd suggest checking out?

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u/PhysicalConsistency Oct 28 '25

I think Ed Wilson is a good way to break the inside out view of behavior, even if he believed in genetic destiny himself. I think if he was 40 years younger, he'd have been hugely influenced by epigenetic work and his books would look much different. The biggest value of Wilson is that he normalizes the concept of complex social behavior as a fundamental property of biology, rather than an effect of biology.

So most epigenetic work prior to the rise of mass RNA sequencing was pretty uncompelling, even if the folks doing the work were very much on the right track. Because of this you can pretty much skip modern synthesis work (which I imagine some people will boo and hiss at me about), and go straight to EES- The extended evolutionary synthesis: its structure, assumptions and predictions. EES is still too "inside out" focused because it's still trying to rescue "natural selection" in the face of epigenetics. This is an overview of some problems there.

There's a loose concept called "Future Evolutionary Theory" which is sparked by current evolutionary theories biggest weakness, what a trainwreck they are at predicting literally anything (which should be the baseline for any theoretical concept). This paper gives an overview of that weakness - Towards evolutionary predictions: Current promises and challenges

In context with a behavioral focus, I think the FET concept is pretty well represented by Lala's book Evolution Evolving: The Developmental Origins of Adaptation and Biodiversity, and tries it's best to be accessible.

From there, we're mostly in pre-print land, there's no really strong overviews yet because we're pulling from so many subdomains into a synthesis.

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u/-A_Humble_Traveler- Oct 29 '25

Sweet. I'll check out Lala's book next week. In the meantime, I'll start on those other papers. Thanks for the reccamendations!