I can offer a small, fuzzy data point on the topic of polygamy.
My best friend in Hong Kong was born into the family of a Big Man in the
pretty-much-ungoverned South China of around 1930. (His home town was
Foshan, in Guangdong Province.) Definition of a Big Man in that time &
place: the guy had his own private army! Anyway, as well as having an
army, Chan’s dad also had several wives. Chan was never sure which one was
his mother. This, he claims, caused him severe psychic distress growing up.
There must be plenty of Asians & Africans of older generations who had
similar backgrounds & can tell stories about growing up under polygamy.