A commenter, who I believe is a physics undergrad (his blog here) emailed me some of his thoughts on narcissism, and wrote:

...those studies where people rank each other in a room for different attributes having never met them... I think what's going on is we assign people personalities based on how they look and force them to become a certain thing, creating a whole custom world for them...

which puts the idea of "profiling" on its head.  Do we actually ever "figure people out," or do we change them into what we think they are by the act of engaging in a relationship (on any level) with them?  It sounds a lot like a psychological version of quantum entanglement:

When two systems, of which we know the states by their respective representatives, enter into temporary physical interaction due to known forces between them, and when after a time of mutual influence the systems separate again, then they can no longer be described in the same way as before, viz. by endowing each of them with a representative of its own... By the interaction the two representatives have become entangled.

Which, unfortunately, sounds a lot like this (p. 236):

The unreflective consciousness does not apprehend the person directly or as its object; the person is presented to consciousness in so far as the person is an object for the Other.  This means that all of a sudden I am conscious of myself escaping myself, not in that I am the foundation of my own nothingness but in that I have my foundation outside myself.  I am for myself only as I am a pure reference for the Other.

You can't know who a person is without relating to them, and once you do that, you irrevocably change them.

Only in relationship to another do you get defined. Sometimes you can do it with your God; but either way, any adjective has to be placed on you by someone else.  Are you brave?  Strong?  funny, stupid, nervous?  All that comes from someone else.  So when someone relates to you, they define you.  You can try to control this-- hence the narcissist preying on the borderline to get her to see him the way he wants to be seen-- but ultimately it's up to the other person.

So we're are, or become, whatever a person thinks we are?  No, it's worse than that-- we want to be what they think we are. That's why we maintain the relationship, otherwise we'd change it.  ("I divorced her because I didn't like who I became.")

We do it because it is easier, and it serves us.   You're kind because he sees you as kind-- which in turn allows him to be seen as someone who can detect kindness.  And you accept that you're kind-- or mean/vulnerable/evil/brilliant-- because it serves you-- there's some gain there.  But a strong person accepts that on the one hand the other person gives you definition, and on the other hand you are completely undefinable, free, at any moment, to redefine yourself.  You can defy him, biology, environment and be anything.

You say: but I can't be a football star just because I want to.  But that's wanting someone else to see you in a certain way.  Do you want to play ball?  Go play ball.  "But I won't get on the team."  Again, that's wanting to change someone else.  Change you first. 

But what about-- identity?  That's the mistake, that's bad faith.  Thinking that our past is us; what we did defines us.  Our past can be judged-- what else is there to judge?- but it can't-- shouldn't--  define us, because at any moment we are free to change into something, anything else.  And so, too, we can be judged for not changing.

Ultimately, you are responsible for everything you do and think.  Not for what happens to you, but for how you choose to react.  Nothing else made you be.  Nothing else made you do.

Trinity said it best: The Matrix cannot tell you who you are.