I’ve certainly seen some intelligence variability in toddlers and am aware from epigenetic studies that stress can be transferred from fetus to child …but, I think a parent’s response to this is partly in his/her own hands. I think most parents (without covid-19) don’t interact with and/or teach their kids enough. My own parents certainly didn’t and I think this is worse these days with smart phones and the internet. I think parenting and social skills can be taught (maybe should be taught). I rarely use geometry in daily life, but am still very much affected by social skills and the after-affects of upbringing (as are we all - I am not throwing a pity-party). You can see a few genetic/ethnic groups who underwent huge amounts of stress and they seem to be doing very well.
Its good to study this topic, but I think the verdict isn’t clear or detailed enough yet.