married to their cousins according to FiveThirtyEight How Many Americans Are Married To Their Cousins? How Many Americans Are Married To Their Cousins? According to FiveThirtyEight, about 0.2% How Many Americans Are Married To Their Cousins? about 0.2% about 0.2% about 0.2% America who are married to their second cousins or close. about 0.2%