So when you say spiritual and unspiritual, you just mean people who did or did not choose to follow God? By your mentioning of 2 separate creations, it sounded like you meant 2 separate races of men.
I don't know if they were 2 separate races of men. Since they intermarried I suspect not. However, the Adam of the Jewish scriptures is to be understood as God's special creation, unlike the others. He was given the special capacity of having spiritual knowledge. He was a new man. Today, in Christ, we too are a special creation, new men. I know it sounds complicated but it isn't really.