Think you can spot an introvert in a crowd? Think again. “A lot of introverts can pass as extroverts.” People are frequently unaware that they’re introverts -– especially if they’re not shy — because they may not realize that being an introvert is about more than just cultivating time alone. Instead, it can be more instructive to pay attention to whether they’re losing or gaining energy from being around others, even if the company of friends gives them pleasure. 
“Introversion is a basic temperament, so the social aspect — which is what people focus on — is really a small part of being an introvert,” Dr. Marti Olsen Laney, psychotherapist and author of “The Introvert Advantage,” said in a Mensa discussion. “It affects everything in your life.” 

Tendencies of introverts: 

1. Find small talk incredibly cumbersome. 

Introverts are notoriously small talk-phobic, as they find idle chatter to be a source of anxiety, or at least annoyance. For many quiet types, chitchat can feel disingenuous. 
“Let’s clear one thing up: Introverts do not hate small talk because we dislike people,” Laurie Helgoe writes. “We hate small talk because we hate the barrier it creates between people.”

2. Go to parties -– but not to meet people. 

If you’re an introvert, you may sometimes enjoy going to parties, but chances are, you’re not going because you’re excited to meet new people. At a party, most introverts would rather spend time with people they already know and feel comfortable around. If you happen to meet a new person that you connect with, great — but meeting people is rarely the goal. 

3. Often feel alone in a crowd.

Ever feel like an outsider in the middle of social gatherings and group activities, even with people you know? “We might let friends or activities pick us, rather than extending our own invitations.” 

4. Think that networking feels like you’re being a phony.

Networking (read: small-talk with the end goal of advancing your career) can feel particularly disingenuous for introverts, who crave authenticity in their interactions. “Networking is stressful if we do it in the ways that are stressful to us,”

5. Are often called “too intense.”

Do you have a penchant for philosophical conversations and a love of thought-provoking books and movies? “Introverts like to jump into the deep end,” says Dembling.

6. May become easily distracted. 

While extroverts tend to get bored easily when they don’t have enough to do, introverts have the opposite problem — they get easily distracted and overwhelmed in environments with an excess of stimulation. 

7. Downtime doesn’t feel unproductive to you.

One of the most fundamental characteristics of introverts is that they need time alone to recharge their batteries. Whereas an extrovert might get bored or antsy spending a day at home alone with tea and a stack of magazines, this sort of down time feels necessary and satisfying to an introvert. 

8. Giving a talk in front of 500 people is less stressful than having to mingle with those people afterwards. 

Introverts can be excellent leaders and public speakers — and although they’re stereotyped as being the shrinking violet, they don’t necessarily shy away from the spotlight. Instead, an introvert might struggle more with meeting and greeting large groups of people on an individual basis. 

9. When you get on the subway, you sit at the end of the bench -– not in the middle. 

Whenever possible, introverts tend to avoid being surrounded by people on all sides. “We’re likely to sit in places where we can get away when we’re ready to — easily,” says Dembling. “When I go to the theater, I want the aisle seat or the back seat.” 

10. You start to shut down after you’ve been active for too long.

Do you start to get tired and unresponsive after you’ve been out and about for too long? It’s likely because you’re trying to conserve energy. Everything introverts do in the outside world causes them to expend energy, after which they’ll need to go back and replenish their stores in a quiet environment, says Dembling. Short of a quiet place to go, many introverts will resort to zoning out. 

11. You’re in a relationship with an extrovert. 

It’s true that opposites attract, and introverts frequently gravitate towards outgoing extroverts who encourage them to have fun and not take themselves too seriously. “Introverts are sometimes drawn to extroverts because they like being able to ride their ‘fun bubble,'” Dembling says.

12. You’d rather be an expert at one thing than try to do everything.

The dominant brain pathways introverts use is one that allows you to focus and think about things for a while, so they’re geared toward intense study and developing expertise, according to Olsen Laney.

13. You actively avoid any shows that might involve audience participation. 

Because really, is anything more terrifying? 

14. You screen all your calls — even from friends. 

You may not pick up your phone even from people you like, but you’ll call them back as soon as you’re mentally prepared and have gathered the energy for the conversation. “To me, a ringing phone is like having somebody jump out of a closet and go ‘BOO!,'” says Dembling. 

15. You notice details that others don’t. 

The upside of being overwhelmed by too much stimuli is that introverts often have a keen eye for detail, noticing things that may escape others around them. Research has found that introverts exhibit increased brain activity when processing visual information, as compared to extroverts.

16. You have a constantly running inner monologue. 

“Extroverts don’t have the same internal talking as we do,” says Olsen Laney. “Most introverts need to think first and talk later.”

17. You have low blood pressure. 

A 2006 Japanese study found that introverts tend to have lower blood pressure than their extroverted counterparts. 

18. You’ve been called an “old soul” -– since your 20s. 

Introverts observe and take in a lot of information, and they think before they speak, leading them to appear wise to others. “Introverts tend to think hard and be analytical,” says Dembling. “That can make them seem wise.”

19. You don’t feel “high” from your surroundings 

Neurochemically speaking, things like huge parties just aren’t your thing. A study “suggests that introverts have a fundamental difference in how strongly they process rewards from their environment, with the brains of introverts weighing internal cues more strongly than external motivational and reward cues,” explained LiveScience’s Tia Ghose. 

20. You look at the big picture. 

When describing the way that introverts think, Jung explained that they’re more interested in ideas and the big picture rather than facts and details. Of course, many introverts excel in detail-oriented tasks — but they often have a mind for more abstract concepts as well. “Introverts do really enjoy abstract discussion,” says Dembling.

21. You’ve been told to “come out of your shell.”

Many introverted children come to believe that there’s something “wrong” with them if they’re naturally less outspoken and assertive than their peers. Introverted adults often say that as children, they were told to come out of their shells or participate more in class.

22. You’re a writer. 

Introverts are often better at communicating in writing than in person, and many are drawn to the solitary, creative profession of writing. Most introverts say that they feel most creatively charged when they have time to be alone with their thoughts. 

23. You alternate between phases of work and solitude, and periods of social activity. 

Introverts can move around their introverted “set point” which determines how they need to balance solitude with social activity. But when they move too much — possibly by over-exerting themselves with too much socializing and busyness — they get stressed and need to come back to themselves, according Olsen Laney. This may manifest as going through periods of heightened social activity, and then balancing it out with a period of inwardness and solitude. 
“There’s a recovery point that seems to be correlated with how much interaction you’ve done,” says Dembling. “We all have our own private cycles.”

(Article on Huff Post, 8-20-2013)