Nature just provides the “plan”, nurture makes the man.
What would happen to persons raised without any interaction with people: what would they become with no nurture?
Not sure they would be “human”.
And no, I do not advocate trying any such thing just to see...
I believe something very close to your theory happened in the Soviet Union or some other dystopian society where many infant orphans were subjected to almost no human nurturing. A large number of the wasted away and died.