Fourth cousins dating
Just to make my example easy, say the couple had 10 children who had 10 children each, for 100 grandchildren.
For one thing, people whose great-great-grandparents had lots of kids will obviously have more third cousins.Long answer: In 26 out of 50 states in the United States, and many other countries, first cousins can marry.Second cousins, third cousins, first cousins once removed, and any other cousins except first cousins can marry in all 50 states and every country in the world.The team found that women born between 18 and who partnered with a third cousin had an average of about four children and nine grandchildren, while those related to their mates as eighth cousins or more distantly had three children and seven grandchildren.A similar pattern showed up for women born between 19.
If you do genealogy, and your ancestors were in the USA west of the Atlantic seaboard before the Civil War, odds are you'll find at least one set of first cousins marrying in your tree. There was a brief span of time in the US (1870 - 1930 or so), after doctors started washing their hands and before birth control was popular, when women routinely had 8 - 12 children, most of whom lived to adulthood.