A group of young adults shyly meet for the first time on the second floor of an empty Manhattan shopping mall. The stores are all closed for the weekend, and other than a man stopping in the lobby to read his phone, this group is the only sign of activity.

“I actually really like clubbing,” shares one guy.

The group goes silent.

“Get out of the circle,” a woman whispers.

Everyone in this group took the Meyers-Briggs Type Indicator (MBTI), a personality test. They all tested as the same type (one that tends to be introverted), joined an online group for others who got the same result, and decided to meet up.

Which explains why they’re meeting in an empty food court: It’s perfect for a group of people who like quietude. In this crowd of 20-something New Yorkers, the clubber is, truly, an oddball.

Katharine Cook Briggs and her daughter Isabel Briggs Myers drew from influential psychologist Carl Jung's theories to invent the MBTI personality test in 1942. In an age of “What Disney princess are you?” quizzes, MBTI is a personality test that, while still reductive, actually indicates something about personality. The test uses four dichotomies to divide people:

Introvert (I) v. Extrovert (E)

Intuitive (N) v. Sensory (S)

Thinking (T) v. Feeling (F)

Judging (J) v. Perceiving (P)

The test ultimately divides people into 16 types, based on the combination of traits they fall into—as demonstrated in the interactive below:

Text used with permission of CPP, Inc.

Some psychologists and many test-takers believe these types say a lot about how people think and interact. Since the ‘70s, researchers have published their findings on MBTI in a peer-reviewed Journal of Psychological Type.

However, others consider the test to be worthless.

University of Pennsylvania professor of psychology Adam Grant says it doesn’t stand up to scientific scrutiny. “In social science, we use four standards: Are the categories reliable, valid, independent, and comprehensive?” Grant posted on LinkedIn. “For the MBTI, the evidence says not very, no, no, and not really.”

Grant points out that the test ignores important personality features, such as the ability to stay calm under stress. Moreover, people often get different results when they retake it. Research shows “that as many as three-quarters of test takers achieve a different personality type when tested again,” Annie Murphy Paul writes in The Cult of Personality Testing.

Additionally, the test relies on all-or-none categories, even when spectrums might be more accurate. For instance, no one is completely introverted or completely extroverted. (Some versions of the test do include what percentage you score for each category though.)

Given all this controversy, you might think people would treat the test as just a curiosity, or at least take it with a grain of salt. Instead, many people use types as a schema for understanding the world. There are blogs that sort Disney characters into MBTI types and YouTube sketch videos that compare types. According to CPP, a company that administrates the MBTI, college and universities worldwide use the test, as do 89 of the Fortune 100 companies.

While there's plenty to criticize about the MBTI, it's easy to imagine that, if you put a group of people with the same personality type in a room together, you'll see a lot of similarities. Thanks to the popularity of online community-building sites like Meetup.com, MBTI personality groups, such as the one in the shopping mall, have actually materialized, allowing test-takers to meet up with other members of their type. Because the best kinds of friends are the ones who are just like you. Or, as Jerry Seinfeld put it in an episode of Seinfeld, “Now I know what I've been looking for all these years...myself! I've been waiting for me to come along, and now I've swept myself off my feet!”

* * *

The young adults in the shopping mall are all the INFJ type—introverted (I), intuitive (N), feeling (F), and judging (J). According to David Keirsey’s Please Understand Me, a book about the Myers-Briggs types, INFJs are quiet, private people who like discussions and care intensely about helping others. The fact that I know this might be coloring my perception, but these traits all seem to come out at the meetup. One person speaks at a time, and comfortable silences break up the conversation. No one seems interested in small talk. Instead, they consider philosophy and personal issues.

In a sense, they're here for the same reason people go to any meetup: to find people with common interests and attitudes. Except in this case, it's not about going out with neighbors who also like to play golf or go to the beach. It's about looking for people with similar minds.

Before coming to the INFJ meetup, I took an MBTI test too. It told me I’m an INTJ, which is only one letter off from INFJ. I have to admit, I definitely felt like I was surrounded by similar people: We were all on time (“judging” types prefer their lives to be structured), relatively quiet (introverted), and focused on digging into theories (intuitive).

And yet I still felt a little disconnected from some of the discussions. I couldn't quite figure out why until one young woman told us about the time she spent 10 minutes in a grocery store trying to choose between fair trade and regular chocolate. She almost broke out in tears as she thought about the suffering workers in third world countries, she said. The others nodded, saying they too got upset in these kinds of situations.

I, on the other hand, kept my mouth shut, knowing that whether or not I bought the fair-trade chocolate, no tears would be involved. I'd weigh the various factors (price, likely taste, likely impact on the world), make a choice, and be fine with it.

After hearing the others talk about how the knowledge of overseas distress caused them emotional pain, I felt a bit guilty. Did my nonchalance make me a monster?

According to the MBTI, the difference between fair-trade-chocolate girl and me is that I am a Thinker (T) rather than a Feeler (F), meaning I make decisions by analyzing rather than by feeling. And as skeptical as I am about putting people in boxes, this distinction felt true in this scenario.

* * *

Leon Sao, a life coach and MBTI meetup organizer, says he’s been successfully guessing his peers’ types since high school. His classmates were surprised how much he could figure out about them, he says, and now he does the same thing at meetups.

“We get to laugh at the eerie accuracy of the MBTI together,” Sao says.

Sao researched MBTI for years before he started running MBTI meetups in October 2014 (he also runs a MBTI YouTube channel). He likes the meetup groups largely because they let him learn about personality types through direct experience.

“You actually get to see the types in action,” Sao says.

Sometimes he runs meetups for a mix of types. Sao claims that each type has its own quirks.

“INFPs live half their lives in a fairytale. Many ESTPs can curse like a sailor and not really care what people think of them. ESFPs are fun and light-hearted,” he explains. “Over time, you get to figure out the noticeable vibe that each type gives off.”

He also noticed patterns in how different types interact with each other.

“The ‘FJ’ types might get irritated with the ‘TJ’ types when the latter start to mess with the group dynamics, such as when the INTJs get into the conversation and say exactly what they honestly think, which may not always be pleasant,” he explains. “The ‘NF’ and the ‘NT’ types try to get an understanding [of] where the other is coming from… to an extent. They still complain about each other."

Sao considers these meetups therapeutic, as participants get a chance to vent about how family, friends, and coworkers of dissimilar types can’t understand why they act the way they do.

“When we get together in the MBTI group, it is like we finally get to express our frustrations,” he says. They often workshop career and personal problems together, and the process usually reveals something about their types.

“The rest of us think ‘Wow, your behavior reminds me of so-and-so of the same type of yours,’” Sao says. “Which is great, because then we can help you out with your issue, since we have everyone's experiences to work off.”

Sao says he once met an ENFJ girl who had an INFP boyfriend. Without knowing much about them, Sao guessed that her boyfriend didn’t share his feelings with others. Rather, he brooded about them when he was alone. And Sao guessed that the ENFJ girl wanted him to verbalize his feelings.

According to Sao, she told him that his description was dead-on. He advised that she give her boyfriend more time to process his feelings but encourage him to be open sometimes for her sake.

* * *

Conflicts between types are, apparently, quite common.

Manju Pradhan, a counseling psychologist who frequently uses this test with patients, says that having the most uncommon female type (2 percent of the population and less than 1 percent of women, according to the Meyers and Briggs Foundation) makes it difficult to be an INTJ woman.

Pradhan points out that INTJs are often socially clumsy. They play devil's advocate and introduce opposing ideas in order to learn, and many find this off-putting. In a society that encourages women to be nurturing rather than logical, INTJ women can be made to feel like outcasts.

“[They're] ostracized for being perceived as unconventional, robotic, and seemingly impersonal,” Pradhan explains.

Pradhan sought out MBTI meetups to meet others like her. But getting involved had an unexpected benefit: Pradhan has found she's better able to deal with people who are different from her.

“If I notice that, as an introvert, my friends may seem more invested in organizing large gatherings and paying attention to the sports event at the restaurant's television bar, I realize they are simply being their natural selves, not undermining our friendship,” she explains.

Pradhan runs workshops to teach others about how other types see the world. She once had participants role-play a job evaluation between a supervisor (INTJ), and employee (ENFJ).

“The ENFJ was judged as 'flirtatious' [by the supervisor] when in fact as an extroverted feeler, she was just focused on doing well at her job as a store manager,” explains Pradhan.

Sao has discovered similar insights. These meetups have helped him notice that things he considers weaknesses could actually be strengths.

“As an INFP, I may feel bad about how little emotion I give off relative to how I feel,” he admits. “But then I meet an INFJ, who feels bad about how much emotion she gives off, betraying how she feels at all times, which is another can of worms.”

He recognizes that every type runs into challenges.

“It makes you relax a bit, and realize that other types have the other side of the coin, which is not necessarily better—it has its strengths and drawbacks,” Sao says. “It is easy to get caught up in our assumptions about the world, but we do not realize that these assumptions are limited to how we are wired. We can work on our personal issues by seeing things objectively from the mindset of the type we are in conflict with.”

* * *

How useful is the MBTI? Psychologists argue about it all the time; even Pradhan and Sao say that the MBTI isn’t all encompassing. Pradhan stresses that the MBTI isn't made to “stereotype, objectify, or pigeonhole anyone” but instead to offer an average experience of each type. There are a lot of reasons to be skeptical of the test, and to be cautious about using it to judge people, whether that be in hiring or dating.

Stereotyping people using the test seems risky at best and harmful at worst. In particular, screening potential employees through the MBTI is probably a mistake, since there’s no proof that you can link MBTI to how effective people will be at their jobs.

But even if the test isn't perfect, people's infatuation with it shows that it’s quenching some kind of thirst they have for understanding themselves and others.

There’s never been a universally agreed upon way to measure personality, and yet, people undeniably have different personality traits that must be taken into account to understand behavior. The test provides one framework to help understand these differences.

Plus, as Sao pointed out, many find their MBTI results startlingly accurate, giving them insights into their own personalities and relationships with others. It seems silly to throw away information that people find helpful.

Perhaps the MBTI is more of a starting point for self-discovery, rather than a finishing line. At minimum, the test points out that people behave differently largely because they view and interact with the world differently. If the MBTI helps people to understand that their conflicts may be the results of these different worldviews, then that alone might make the test worthwhile.