I can just post whatever but my folders need to be organized
When incest happens, people believe the baby will be retarded. It's harder than that genetically and it takes generation of incest to have high probability of having a retarded child.
While this is perfectly true, it's also true that such a narrow genetic mixup has a much higher risk of bringing out negative hereditary traits that the sibling parents themselves were spared.
Not sure, got them from another thread