In actuality, the White race is of the least, if probably the least of the least of 'inbred' people. This practice has been an abomination to Whites since time immemorial, proven recent by genetics as to why. If people were doing incest, the White race would have been plagued by an infinite amount of hereditary diseases, even if this was practiced a few generations back.
Practicing incest is one of the fastest ways to destroy one's race, it's a genetic recipe of disaster, and totally mental illness, cursed by nature. It cannot be 'hidden' either, it shows on a race.
Jews are by far the most inbred race even in this day, and have hundreds and hundreds of inherited jew exclusive diseases as a result.