People out there have a lot of funny ideas about quiet people, the worst one being that all quiet people are alike. There are about 10 million reasons why someone might not talk very much, running the gamut from being shy, to hating you, to having sold their voice to a witch in return for legs.
People who don't recognize this come up with their own ridiculous assumptions about what quiet people are up to. Even quiet people themselves are guilty of assigning their own traits to all other quiet people in the world.
Here's a few of those assumptions.
There's a common assumption that all quiet people really want to be talkative, but can't be. They just lack confidence, or are really bad with words, but if you just reached out a helping hand and gave them a gentle push, you could rescue them from their silent prison, from which they must constantly look out in misery at normal people talking and enjoying themselves.
First, many people are pretty comfortable with not talking very much, for various reasons other than having low self-confidence or bad social skills. Or at least they are comfortable until someone makes a point of how little they are talking and tries to awkwardly force them into spitting out more words for the sake of words.
Even the people who do just lack confidence and wish they could be more chatty don't usually appreciate the kind of "help" usually offered, which might involve suddenly putting them on the spot in a group conversation, or pretending one of the few things you know about them is suddenly a very interesting subject to you.
"So I hear you work in an accounting office! Tell me all about it! I bet you have a ... desk ... and everything!"
Other well-meaning tactics involve pushing them into some embarrassing party participation role, like forcing them onstage for karaoke, making them chug something, pushing a stripper on them, or whispering to the waiter at T.G.I. Friday's on their birthday so the whole staff will come over and sing one of those humiliating songs, all in the name of getting the person to "loosen up" and "come out of their shell."
Even worse, when they do gamely participate, the horribly awkward results are often applauded with extremely fake and over-the-top enthusiasm, as if the person's budding confidence is extremely fragile and every sign of progress must be heavily nurtured.
"Man, you really ROCKED that version of 'Don't Stop Believing'! Who knew you were such a wild man!"
The root problem is projection. A lot of people just think, "If I wasn't talking, that would mean something was wrong, and I would want someone to pay attention to me, put me on the spot, and push me into something crazy. That would snap me out of it!" Which is probably true for them, but different people have different personalities, and for some people, that's the wrong cure entirely, while for some other people, it's not even a problem that needs a "cure."
Before jumping right into "helping" a quiet person, maybe it's best to figure out what's behind their lack of chattiness. Which is a whole new set of misconceptions, like ...
The assumption here is that quiet people are quiet because they don't know what to say, or how to say it. They'd like to make jokes, but they always come out awkward. They want to make cleverly flirtatious comments about how young the host's lovely wife looks, but somehow it always comes out sounding like they are planning to rape her. And that's why they stay quiet.
"Sir, your wife looks so young I thought she was your daughter at first! I'm sure her genitals are quite taut! Er ..."
Knowing when, and to whom, it's appropriate to say things has nothing to do with how quiet or talkative you normally are. There are embarrassing faux pas blurters among both quiet and chatty people, and there are tactful wits in both groups too.
Sometimes quiet people tie these things together as an excuse, since if being quiet is part of your personality, and lack of communication skills are tied to being quiet, well, you can't be expected to do anything about it. This is bullshit.
I'm a quiet person, and also used to be terrible at saying the right things in public, starting from when I was in children's Sunday school and we all had to fill out a registration form. I was so proud that I had seen forms before that when the teacher was explaining what "M/F" meant, I remembered what the field was called on most forms and shouted, "IT'S SEX!" in front of 50 children and about five teachers including my mom. I learned very quickly that while there is nothing wrong with sex, that is not the place and volume to proclaim it.
Makes a good "Kids Say The Darnedest Things" story later though.
Look, if you have some form of autism spectrum disorder or Tourette's, then of course that's going to be a real problem that can't be solved with just practice and common sense, but being quiet isn't either of those things. Talkative people might find out by trial and error, but quiet people can find out just as well by watching talkative people trying and erring. Not talking isn't an excuse to not observe.
And if you really can't do it on your own, some therapists do life skills coaching. If you're put off by the idea of therapy, just think of it as coaching, or personal training. You can learn how to participate in conversations same as you'd learn to run a marathon -- with a lot of practice and sweating and going to the bathroom in your pants.
Only while you are practicing. In actual situations this is considered socially inappropriate.
Just because you don't naturally like to talk doesn't mean you can't intellectually learn the right thing to say so you can hit on someone you're interested in without being pepper sprayed, or deal with customer service without being rerouted into the "difficult customer" queue.
Most people fit quiet people into the "shy nerd" stereotype, where the quiet person is intimidated by other people, or is afraid of being laughed at, or undervalues him or herself. But as long as we're going to movie stereotypes, there's also the silent kung fu master, who doesn't need to say anything, even when insulted, because he knows damn well he's a kung fu master and can remove your spine whenever he wants.
Just saying, when you see those old people in the park doing the tai chi, you should give them a wide berth.
I'm not saying that smiling arrogantly because the words of lesser mortals mean nothing to you is a positive thing, but just demonstrating that a completely overconfident person can be just as silent as an extremely under-confident one. And there are lots of other reasons that people of varying confidence levels might not feel like talking much.
Just off the bat: They could hate everyone present, they could be tired, they might not know very much about the subject you're discussing, they might not believe in small talk, or they might be worrying about other problems, like whether they buried their victims deep enough.
Six feet. Don't be lazy.
All kinds of different people have all kinds of different ideas of when they should and shouldn't talk. It's when a person does decide to talk that you can evaluate their confidence levels. If that person who was giving you monosyllabic responses a moment ago is suddenly up on stage giving a dynamic speech, maybe they were busy rehearsing their speech in their head while talking to you. Or maybe they hate you. Who knows.