Board Thread:General Discussion/@comment-72.161.235.175-20150929151551/@comment-25396609-20151017042058

They are not truly hereditary but can be influenced by parents/lineage.

It's really not complicated, but I am terrible at explaining things. Just think of it like this: two faunus parents will almost always have a child with faunus traits, two humans will almost never have a child with faunus traits (accounting for dormant genes of an ancestor somewhere who was a faunus) a human and a faunus parent will sometimes have a child with faunus traits.