We all know people who tend to be quiet, maybe even a little shy. They don't exactly skulk around the periphery of our social gatherings, but they are far from center stage. These folks are happier behind the camera rather than posing in front. They don't just not seek out the limelight, they actively avoid it. They make excellent audience members. They are often the first to arrive at a party (to avoid the crush), and always the first to leave (to escape the crush). These people are introverts.
Introverts thrive in the unkempt fringes of the social garden. They wither when brought into crowded rooms. If you want to bag an introvert, you must meet her in her preferred element. You must approach cautiously, making as little noise as possible, and you must be alone. It might seem like a lot of work, but it's worth it; introverts make loyal and devoted friends, as long as you don't make them go to concerts or ballgames with you.
During the holidays, introverts do their best to follow the social norms. Because of social pressure, introverts will show up to family gatherings. They will dress up, bring presents, and gamely put on a happy face for as long as they can. They may even look like they are enjoying themselves. You may see the introvert reclining on the couch between Aunt Ida and Aunt Oda, laughing his head off. You may see her carrying on a lively conversation with Uncles Red and Redder, smiling like she's having the time of her life. Especially if she has been drinking. But you should be aware that inside every introvert is a silent people alarm. When it goes off, the introvert starts to sweat. He will leap off the couch like he was goosed. If you blink, you will miss her as she is gliding out the door.
Don't take it personally. It's not that they don't like you. One at a time, you are just fine with the introvert. It's the group of you that is overwhelming to the introvert—the noisy, boisterous, endlessly talking, space-encroaching, energy-sucking group of you.
Introverts like to believe they are special. They go to great lengths to be unique. They may dress strangely. They may speak oddly. They really are exotic creatures. Try to accept them as they are, whatever that happens to be today. Long hair, green hair, no hair... tattoos, piercings, plaid pants, whatever it is, try to avoid showing your distaste or amusement. Whatever you do, don't ridicule them in front of the crowd.
Here's the thing about introverts. They are unpredictable. You may think you know them, but you really don't. They are skilled at presenting a socially acceptable facade. If you snarkily comment on their weird garb, they may laugh with you, but you won't know that inside, underneath that facade, they may be plotting your downfall. They may be planning revenge. They may have mapped the building and blocked the exits. They are exotic creatures, but sometimes exotic creatures have sharp teeth and deadly nails.
So, when you attend your holiday socials this year, pay attention to the family members who are quietly reading a book or watching TV in another room. Watch especially for the ones who are torturing the cat or the three-year-old nephew when no one is looking. Introverts are easy to miss. Observe discreetly, though, so you don't send them running for the exit. And if they need professional help, for god's sake, make sure they get it.