There is a common proverb in my Chinese dialect Fujian spoken today in China Fujian province, Taiwan, Singapore and Malaysia, which says
“A nephew is like his maternal uncle” 外甥像母舅
In modern Biology we know mother passes some genes to her children. Some disease like colorblind is carried by mother down to her sons, the mother herself is immune but her brothers are colorblind as the nephews.
Interesting behavior, intelligence are also similarly inherited from mother and maternal uncles.
Two greatest mathematicians in the history, Newton and Gauss, were the lucky nephews from their maternal uncles who were highly educated to spot the nephew’s genius, although the boys’ parents were uneducated.
Newton’s father died early, mother Hannah Ayscough had a brother William Ayscough educated in Cambridge. William convinced Hannah to send the talented boy Newton to Cambridge.
Gauss’s father was a bricklayer, mother Dorothy Benz had a younger brother Friedrich Benz, who was an intelligent man, rescued young Gauss from following his father’s footsteps as bricklayer.
I met two talented boys, one won the top International Math Olympiad prize, the other excels in the national PSLE exams, their respective mother and father are not highly educated, but their maternal uncles are top scholars.
However, there are serious consequences of (Parallel or Cross) cousin’s inter-marriage from maternal link. Charles Darwin first discovered this genetic problem because he and his wife were such cousins.
The ancient Chinese liked to marry between cousins from maternal side. We praised the practice as “close relatives getting closer” 亲上加亲. The daughter-in-law would likely get along well with the mother-in-law because of the maternal family blood link. The last Qing dynasty emperors were the products of such marriage custom, and most of them were incompetent emperors who died young.
This widely mal-practice of inter-marriage had probably been the cause of the decline of the brilliant Chinese civilization from 14th century (Ming dynasty). China went to sleep for 500 years till awaken from 1911 – as Napoleon imprisoned by the British in St. Helena Island warned the British not to wake up the ‘sleeping lion’, else China would shake the world (*) (she does today as the World’s 2nd super-power) – by the European colonizers (#) in Opium wars and the Japanese invasion.
This Antropology of Kinship Problem is interestingly a modern math problem in Group Theory, first studied by André Weil for the Australian aborigines.
Notes (*): Napoleon’s famous warning to his British enemy before the Opium Wars which humiliated China:
“Quand la Chine s’eveillera, la terre tremblera.”
(#): England, France, Germany, Russia, Japan, USA, Austria and Italy. Ironically France was led by Napoleon’s nephew Napoleon III.