Kissin' Cousins -

: In the 19th-century U.S., a shift began as medical and religious authorities began associating cousin marriage with "idiocy" and genetic defects. This led to many states enacting bans that remain today; 30 states currently prohibit first-cousin marriage.

: For first cousins, the risk increases to roughly 6%. While this is a doubling of the baseline, some researchers argue it is not as high as public stigma suggests. Kissin' Cousins

The "kissing cousin" trope is a staple in storytelling, often used for comedic or dramatic effect. : In the 19th-century U

: Children of unrelated parents have a 3% risk of congenital defects. : In the 19th-century U.S.