Each person is a working example of what every human can possibly be. I regard each human as an experiment like a big pot of belief or choice soup.
This assumes of course that humans share some commonalities - that in fact each of us could be any of us by simply having made the same choices. Clearly the situation is more complex since we are not all born into the same situation. But bear with me as I explore this.
Each person has made a different set of choices as to who to be and how to live. I like to watch them and vicariously live all of the possible lives. It frees me up to live my one life without going insane with the arbitrariness of my personal choices. I can experience many possible lives by knowing people closely enough.
That I don't regard people as much more than experiments may be cause to worry.. but being an experiment in human potential is quite an honour. Only death is guaranteed. The rest is made up as we go along.
In the Popperian traditional, I might instead perceive each person as a theory in environmental adaptation. Then I could add in some standard by which to decide whether that person has succeeded or not. But this is the sort of thinking that pushed my into thinking of each of us as an experiment. Essentially, to do more then examine and sort is to judge. And I don't feel in a position to judge which type of life is the best to live. I don't even begin to think that mine is the best. Far from it. [My Kitten says hi. I mut fondle his ears for a moment.}
To be an experiment is to try out various things and sort them into good and bad piles. Each of us can be seen as a collection of such sortings. Where most people stereotype those they meet so as to get a head start on understanding them, I instead look for the crucial choices they must have made in their life. I also try to order them in time, and in significance. For instance, Peter chose very early onto believe that honesty is the best policy. I chose very early on to protect my innocent core personality at all costs. Both of these are examples of choices that occurred are early in life and are high in significance to their respective havers.
So I look for a person's choices, and after awhile I end up with a kind of choice map of who they are and what they are likely to do. This allows me to trust1 them no matter who they are.
All of this implies that I find it difficult to disapprove of any human being. I find this is an ultimate form of two rarely characteristics: tolerance and judgement -- both of which I highly value (but that may simply be because I'm from Toronto!).