It is interesting that there is mentioned speculation of physical developmental conditions that determine intelligence. Yet, there is no mention of mother's methylation factors that are known to produce conditions or disease in the new born. Certainly there is opportunity to explore methylation's affect on the G-factor.,(reply>), @nehorlavazapalka I've read about maternal stress affecting development &amp; plasticity of the visual cortex as well as structural changes in the amygdala.,(reply>), @nehorlavazapalka I've read about Maternal stress leads to overweight in children. Are there other links less talked about?,(reply>), @Rusty yB yes, all the effects appart from direct genetic control are very weak, as they should and need be,(reply>), @nehorlavazapalka so it is very well understood?,(reply>), almost certainly near 0