This question arose from the understanding that God being one nature and three persons. Though (I am trinitarian myself), I observe that in these discussions it is presupposed that humans have one nature and one person (here and here).
So I ask: Is there a single human nature or there are multiple human natures?
If you answer one human nature = multiple human persons, how come that (unlike God), we speak of humanity as "beingS" and not "being"? but;
If you answer one human nature = one human person, what then do we mean when we say "human nature" in a collective sense (ex. "It is human nature to XYZ.")? What do we make of the similarities of our own individual natures? And is it right to say instead that we have "multiple yet similar human natures"?
UPDATE: I was looking through this few days back, and I think I found resources that profoundly helped me in this question.
Here's a Catholic Exchange article discussing 'individuation', to quote:
"Remember, Aquinas says, that a person is “an individual substance of a rational nature.” On first blush that seems to work quite well. But hold on. Something shouldn’t sit well with us in thinking about individuals within God. Surely Father Son and Holy Spirit are not three individual persons having the divine nature in the same way that John, Joe, and James are three persons having a human nature.
Aquinas readily recognizes this objection. He notes that ‘individuation’ only happens when we’re talking about matter—which we have, but God doesn’t. So when it comes to God, we have to recognize that we use the word ‘person’ with a meaning somewhat different than when we talk about man. In the case of God, Aquinas says we have to use Richard of St. Victor’s definition of a divine person as “the incommunicable existence of the divine nature.”
Another resource I found is James E. Dolezal's All That is in God - a subsection in Chapter 4 called Real Distinction among Divine Persons. (albeit just a Google Books preview. One has to click it as the text can't be copied).