Not condoning incest, but one generation of incest is extremely unlikely to result in any genetic diseases. It's repeated generations of incest that makes deformities likely. Whereas breeding with a low-IQ subhuman is guaranteed to produce a low-IQ mutt.
>YEAH WE SHOULD JUST PRACTICE INCEST
or some retarded nigger comes along
>WHAT DO YOU MEAN? THEY'RE YOUR CHILDREN HOW CAN THEY BE LESS GENETICALLY RELATED TO YOU