Which One Is The Narcissist, Which Is The Target?

So a couple you know seems to be opposites of each other. They might also be a pair of friends, a pair of siblings, or a parent/child pair. One of them is talkative and warm, confident, well-rounded; generous and giving, responsible and knowledgeable. The other one seems shy, introverted, less experience, less knowledgeable, less warm, or even cold, and perhaps sullen or "stuck up".
When they're around, you tend to talk to the outgoing one, but you find yourself "trying to be polite" to the other one. You tend to judge the outgoing one as a "great person", and the other not-so-much.

Do you think you know the whole story?
Did other people tell you that the outgoing one is "wonderful" in so many words, and that the quiet one is "weird", or "burdensome", or something to that effect?
Do people tend to COMPARE them to one another, and make one of them "good" and one of them "bad", one of them a "winner" and one of them a "loser", one of them an "innocent" and the other one "taking advantage", etc?

People we know present different "personalities" on the surface, and that's what we tend to respond to. If they present as "happy" and "warm", we tend to think of them as lively, energetic, attentive, giving, and fun to be around.
If they seem shy, sullen, or more introverted, we tend to think of them as less so, and even self-centered, whiny or "weak".

There is a huge problem, however, with the way we tend to judge others. We really don't look beneath the surface. We respond and judge by the way a person seems to ACT socially, but we don't really pay attention to what they DO, or what they're really saying, or how they TREAT other people.

We also forget about relationship dynamics and social signals.

WHY does a person who is so "warm" and "giving" choose a partner who is apparently cold and shy?
WHY would a child of a person who is "warm" and "giving" seem cold and shy, sullen, or introverted?
What's really going on there?
Is the "cold" one a "Controller"?
Or is it the "warm" one the "Controller"?

There are a couple of ways we can observe what's really going on, and perhaps get a more accurate view of the dynamic, and better understand people we know or that are in our family.

The first thing we need to understand is that a "WARM PERSONALITY" does NOT automatically indicate a genuinely "KIND PERSON" with a "KIND HEART". It MIGHT, but it just as easily might be an act, or just the way the person grew up, adapting the behaviors of those around him or her.
The second thing we need to understand is that a seemingly "COLD" or "SHY PERSONALITY" does NOT automatically indicate that a person is "INTROVERTED", "SELF-CENTERED", or "HAS LOW SELF-ESTEEM".

The third thing is that the way people SEEM TO US does NOT necessarily indicate their "personality", their LIFE, what their real motives and agendas are, or the way they treat those who they're close to.

People have years to learn how to act and behave before they reach adolescence, and years more before they reach adulthood. ("They" meaning "we", all of us.)
So a person with a Narcissistic agenda is MORE LIKELY to learn how to put on a show and come across as a "GREAT PERSON", because they've seen how others respond so favorably to that kind of personality, and they know it will open all kinds of doors.

A person may ALSO adapt "tough" or "cold" behaviors on purpose, in order to elicit a different response from other people, such as the kind of false respect that people give to those they're unsure of, or who they fear for whatever reason.

A narcissistic person may also adapt "logical" or "smart" as a personality presentation, or "funny and endearing", or "cool", or "innocent and vulnerable".

Any of these personality presentations elicit a RESPONSE from others.
A non-Narcissist might really be "warm", "giving", "tough", "sweet", "smart", or "innocent". 
But a person who does have Narcissism will use one of these (or more than one) as a COSTUME, as a MASK, in order to present themselves a certain way so others will respond to them and think of them a certain way.

All that being said, a Narcissist is more likely to come across superficially as CONSISTENTLY a certain way, because it's not really "them", it's a mask they're holding up, a costume they're wearing. Only those who are CLOSE to them get the real person, and get treated accordingly.

So, when we see a couple, or a pair of friends, or a parent/child couple, and we want to know what's really going on with them, we can observe a few things:

1.) Which one do WE tend to talk to out of the pair? Which one do WE seem to automatically connect with, pay attention to, listen to, speak with, and which one do we tend to avoid or ignore, even if they're standing right next to each other?
If one of them really is a "Controller" or "Narcissist", then it's the one we pay attention to. 
It's about subtle social signals that we don't know we're responding to, and also our own desire to associate with "popular" people, and avoid "unpopular" people.

2.) Which one of them talks about themselves? Which one of them makes announcements about what they did, what happened to them, what they're doing, their job, their accomplishments, their kids' accomplishments, their aches, pains, and their latest problems, and what they're doing for others?
And how much does the other person announce or boast about themselves, their lives, their problems, their kids, or their good deeds?
The answer to this one is obvious, but we don't seem to realize that we often buy into the boasting when it's happening, and also buy into our own assumption about a person who doesn't boast not having a "life", not being that smart or capable, or doing much "good".

3.) When they are both present, how are their MANNERS? Which one allows the other to speak? Which one interrupts the other when they speak, on a regular basis? Which one CORRECTS the other in front of others, argues with them, or counters them on a regular basis?
(And how do find yourself reacting when it happens? Do you go along with it, ignore it, participate?)
This is domination behavior, much like when a dog displays domination signals toward another dog. It doesn't mean the one showing dominance is smarter or better, it just means that they like to dominate.
4.) How much does one talk about the other person in a positive way, compared to the way they talk about themselves? Do they refer to the other person as a "WE", INCLUDING the other person with themselves when they talk about accomplishments, adventures, projects, or experiences?
Or do they seem to leave the other person OUT of everything they do?
Do they talk about someone else all the time in a positive way (like another friend or relative), but not the person they're often with?
This is about painting a picture of themselves without the other person in it, so others will remember the "story" with only one main character, THEM. A person with Narcissism might describe their own wedding or the birth of their child as if they were the only ones there, or the only one that experienced any of the events that happened. They might add in a "WE" here and there when they catch themselves or fear getting "caught", but for the most part, they'll talk about most of their experiences, good or bad, as if they are the star of the show, the leader, or the only one there.

5.) Does one of them make subtle negative references to the other? And more importantly, does one of them GO ALONG WITH OTHER PEOPLE'S NEGATIVE REFERENCES OR TREATMENT TOWARD THE OTHER? When people are obviously polite or warm toward one of them but rude and cold toward the other, what's the reaction?
Narcissistic people delight in this kind of thing. They love it when they're getting the "star" treatment, and the person they're with is being treated rudely by others. This confirms their belief that they're better than the other person. They don't stand up for the person, they don't do anything at all to correct the dynamic (like purposely introducing their partner, or interrupting the rude people to speak directly to their partner, or putting their arm or hand on their partner, child, friend, or sibling to show solidarity. If and when the person who was treated rudely reacts in some way, or says something about it later, a Narcissist will DEFEND THE RUDE PEOPLE, and him/herself. As opposed to a non-narcissist, who would empathize with and defend the person who was treated poorly.)

6.) Do you get the sense, deep down, in the back of your mind, that if you were to treat them both with the SAME RESPECT, that one of them might get offended, be hurt, get jealous, or stop liking you?
Which one of them do you treat with MORE RESPECT, courtesy, and attention because you feel like that's what they want?

7.) Does one of them seems to step in front of the other one, as if they're onstage?

8.) Does one of them seem FATIGUED, and the other seems to be filled with energy or strength?

9.) Does one talk about the other as if they're their PARENT instead of their peer? Does an adult child talk about their parent as if the parent still has authority over them? Does a partner talk about the other as if their control is driving them crazy?
(This can go either way; Narcissists do try to control targets, so that could be what's really going on, but on the other hand, Narcissists will talk about their target as if they're the Controller, in order to create the "story". Literally, all this tells is that there is dysfunction, but not who is "controlling" who. Like # 10, all the other factors would need to be added.)

10.) Does one of them come across as "very attractive", "very knowledgeable", and "very warm", but the other one, to you, seems "less intelligent" or "less confident" overall, "pinched" or "worried"?
This one is not a good indicator either of which is which, it could go either way. Because while a Narcissist who feels like he or she has accomplished being seen as the "better one" will of course be happy, the Narcissist/Controller who feels like the other person is being perceived as the "better one" will be UNHAPPY. So this alone is too superficial. Behaviors, actions, and actual words and speech would be needed to make any kind of observation.

We can make these observations in order to learn more about ourselves, as well.
Narcissism, control, disrespect, neglect, and abuse can't exist in society unless other people are complicit, either knowingly or unknowingly. We humans tend to be very naive when it comes to judging other people, and we tend to use the most superficial information in order to make huge assumptions about others, for good or for ill. That's why Narcissists often get past our "radar".
They know what signals to put out there to make themselves look like a great person, and they know how to push other people's "buttons" to make them look like a not-so-great person.
They also know about other people's general BIASES and PREJUDICES, so they know that it's easier to get you to DISLIKE one person because of the way they look than another.

The best way to protect ourselves and others against Narcissism and Control is to learn more about ourselves, our own tendencies to assume, our own biases and prejudices, and our own tendencies to believe what we want to believe, instead of what's really there.