40 Creepy Facts About The Black / Lestrange Family From Harry Potter
They Practiced Inbreeding
Because the wizarding world is so small, inbreeding is a fairly common occurrence for those looking to keep their family lines pure. The Blacks practiced inbreeding more than most families, which may have explained why some of the family members seemed a little bit ~off~.
Although genetics are never a huge topic in the Harry Potter series, it’s a safe bet that the same genetic rules apply to wizards as they do to muggles. Inbreeding might be okay for a little while, but eventually, it’s going to lead to some severe genetic defects. Maybe having some babies with muggles is actually the best thing for the Black gene pool.