Board Thread:Boruto Discussions/@comment-33066801-20170910125949/@comment-734582-20171006070644

ExyleCage wrote: Scientifically, birth defects caused by incest are extremely uncommon. It's a myth spread hundreds of years ago so that siblings wouldn't tie the knot. In actuality, the only reason birth defects occur is due to an abnormality in the nervous system of one of the parents. It's not so much the one-time act as it is repeated inbreeding that's bad. It's why many dogbreeds, especially the inbred ones, are so weak.