mintything replied to your post “Since people learn their first language by just always being around...”
Actually, some parents teach their children some sign language before they can speak, so that they can still communicate the things they want or need! So maybe sign language is actually easier for babies to understand and learn?
Damn i can't even imagine what that is like. Especially since, I assume, the parents still talk and the child instinctively tries to imitate an therefore communicate with the spoken language.