Interesting stories!

My father comes from a highly educated family where everybody had a University degree (a 'simpler degree' for the girls, PhD or equivalent for boys).
My mother went to school only until she was 14 and then started to work. Neither her father, nor her mom (my grandparents) had high studies. Yet, now I recognice several signs of giftedness (and underachievement) in her and her family.

I think that while for having a PhD one must have at least 1-sigma above average, the oposite is not true: not having any higher education does not mean that one cannot be at 2 or even 3 sigma above.