“What are you reading?” my bus mates asked me on tour this summer.

“Quiet by Susan Cain. It’s about why introverts deserve to live.” Leave me alone; I’m reading.

The subtitle of the book is “The Power of Introverts in a World That Can’t Stop Talking.” Besides the Bible, it is one of the most helpful books I have ever read.

Defining extroversion and introversion may be best described as being high-reactive or low-reactive. Introverts react more strongly to highly stimulating environments, causing them to prefer solitude, to dislike multitasking and to prefer classroom lectures rather than group discussion. When introverts are described as being “shut down” during group activities, it may be because they are experiencing sensory overload, and are struggling to know which parts of the environment they should pay attention to. This is why some introverts find group activities “exhausting.”

Cain cites an experiment on babies that succumbed them to strange or stimulating environments (balloons popping, the scent of alcohol, etc.) Babies who cried loudly and waved their arms in response to these new environments were described as high-reactive and grew up to be introverts. Toddlers who were unfazed by a strange clown and a robot in the room, were described as low-reactive, and grew up to be extroverts; they tended to be unfazed by, indeed, readily sought out, new stimuli.

These differences are proven by physical means in adults. Introverts, when tasting lemons, produce more saliva than extroverts — they are more reactive. Introverts also have physically “thinner skin,” causing them to sweat more (especially when visiting environments that are new to them). This physical reaction hints at the internal warning bells that researchers continually record in introverts’ brains. (Correspondingly, this also points to a physical embodiment of “cool” for extroverts. The unfazed, hip teenager, who always knows what to say, has skin that is quite literally “cooler” than his peers.)

Introverts and the church

The evangelical mega-church service, with its Jumbotron screens, pumping music, PowerPoint sermons and Bible-less sanctuaries, caters to extroverts. Adam McHugh, an evangelical pastor, after visiting Rick Warren’s Saddleback Church, commented, “Everything in the service involved communication. Greeting people, the lengthy sermon, the singing. There was no emphasis on quiet, liturgy, ritual, things that give you space for contemplation.” Personally, I’ve often wondered why it is that I’m so drawn to liturgical services. Perhaps it has more to do with my temperament than with theological aversions to the evangelicalism of many Mennonite-ish churches.

Here are some more things I learned:

We are the 33 percent: One-third of us humans are introverts.

How we act: Extroverts are more likely to commit adultery than introverts. Extroverts also function better without sleep. Introverts, however, more often learn from their mistakes, delay gratification, and ask “what if.” Things that are not related to extroversion and introversion include shyness and being a good leader.

Born this way: Is personality inheritable? Cain responds that “half of the variability in introversion-extroversion is caused by genetic factors.” In other words, 50 percent of the difference between you and another personality type might be related to genes, but it might not be, too. Personality is categorically related to both nature and nurture — your in-born temperament is not necessarily your destiny.

But Cain reminds us that “people who inherit certain traits tend to seek out life experiences that reinforce those characteristics.” You’re an extrovert who loves risk? It’s more likely that you’ll keep seeking and encountering excitement and experiences which will compound over time, and before you know it, you’ll be able to achieve things introverts only dream of doing, not because you’re an extrovert, but because you’re an extrovert who has sought out experiences that persons with other temperaments tend not to.

This is why, as psychologist Jerry Miller notes, “the university is filled with introverts. The stereotype of the university professor is accurate for so many people on campus. They like to read; for them there’s nothing more exciting than ideas. And some of this has to do with how they spent their time when they were growing up. If you spend a lot of time charging around, then you have less time for reading and learning.”

Small talk vs. deep talk: A temperament feature that is closely related and highly overlaps with “highly reactive” is “high sensitivity.” Most introverts find themselves to be highly sensitive, and this may explain why introverts tend to dislike small talk. High sensitives tend to think in complex ways, as demonstrated by an experiment with first-graders, which found that high-reactive children take much longer in the classroom to choose an answer in matching games, or when reading unfamiliar words. Therefore, “if you’re thinking in more complicated ways,” says Jadzia Jagiellowicz, the lead scientist at Stony Brook, “then talking about the weather or where you went for the holidays is not quite as interesting as talking about values or morality.” We are famously told that introverts don’t do small talk, but Cain found that introverts do participate in small talk, but normally at the end of the conversation, not the beginning. After introverts have established authenticity in a conversation by discussing a deeper topic, only then do they deem it appropriate to “relax” into small talk.

Shyness and the animal kingdom: There’s a whole interesting section about how shyness works in the animal kingdom, and how if shyness is a desirable trait for natural selection, or not. It’s reported that of the 100 species that have noticeable temperaments, 80 percent of animals within a certain species are extroverts, and 20 percent are introverts.

For every eight outgoing Trinidadian guppies, there are two loners in the group, who prefer to “watch and wait” instead of to “just do it.” Neither trait is preferable, necessarily, except for the environment each guppy is in. If guppies find themselves in an area full of pike, their natural predator, scientists notice that the outgoing guppies die off with lightning speed, nature preferring the quieter, more cautious guppy. These cautious types, while still casting a wary eye toward pike, manage to throw off their shyness long enough to mate, and guess what? A whole new generation of fish are born, and in time, the genes mutate, leaving mostly shy guppies. But in areas upstream where there are fewer pike, the outgoing guppies have no qualms with bouncing around, looking for food any old time, and since loner guppies tend to “hunt” less, nature then prefers, and promotes, outgoing guppies.

Guilt: Introverts report feeling higher levels of guilt, which is not altogether a bad thing, as Cain reminds us that guilt is “one of the building blocks of conscience.”

Pleasure: The pleasure “reward center” of an average extrovert’s brain is more sensitive than the average introvert’s. That is, extroverted people report higher levels of pleasure for many types of rewards received. (Perhaps this is why introverts are able to delay gratification more easily than extroverts. They don’t get as much out of sex, chocolate cake and roller coasters.) This is also why introverted students consistently outperform extroverted students in high school and college. Cain reports, “At the university level, introversion predicts academic performance better than cognitive ability.” Introverts are extremely disciplined, focused problem-solvers while at the same time excelling in assessing long-term goals, while extroverts are less-focused problem-solvers and tend to overlook the long-term, focusing only on the task at hand. In a sense, extroverts’ lack of discipline shows how they may have less grit.

Vocation: There are many ways in which the work force (and the classroom) has historically catered to extroverts. She also speaks about the importance of introverts finding vocations in which their needs are met, where there is enough solitude for insightful discovery. There are times and places in which introverts can “fake” extroversion, for the sake of vocation, or for a task or topic about which they are very passionate. Oftentimes, though, this pseudo-self gets burned out over time. So if you are in a vocation that requires you to have more “people-time,” or stimulation than you are prepared to healthfully engage, you must work at negotiation with your boss to find the mental rest that you need.

However, Cain found one study that suggests that “introverts like people they meet in friendly contexts; extroverts prefer those they compete with.” Therefore, introverts may find it really difficult to negotiate for “a night in,” or “a silent working lunch” because they perceive negotiation as conflict. Conflict is then internally perceived as guilt (for introverts), when extroverts might just be getting their engines started. This is why introverts must continually work at not shutting down, but learning to firmly ask for the things they need.

Cain’s narrative turns personal when she begins to answer the question many introverts have upon reading her (vindicating) research — How do I find a vocation that meets my need of being a core personal project? She gives three answers: “First, think back to what you loved to do when you were a child. … Second, pay attention to the work you gravitate to. … Finally, pay attention to what you envy.” Envy, as nasty as it is, can teach us a lot about our desires.

Why does this matter?

Cultures and societies generally prefer, promote and value one temperament over the other. Cain’s book makes a strong case for American culture preferring extroverts, versus Asian respect for introverted qualities. Yet Cain also points out how a society’s preference for a certain temperament can have long-lasting impacts. Cain makes a grand case that the recession of 2008 resulted in part from American society idealizing extroversion in business schools, and accordingly undermining, and even ignoring, introverts. Her extensive research from some of the top business schools in the nation is mind-boggling as she makes a very tight case. My question is this: If a cultural preference for one quality over another can cause a national financial crisis, what else might we be on the brink of losing, due to our collective aversion to the slow and steady deep thinking that so many introverts hold dear?

Let’s think about introversion and extroversion in the church. One of the deepest impacts from my classroom last year was the following realization: society is made up of the kind of students I have in my classroom. In the same way that my high school classrooms consist of readers struggling to decode a single paragraph alongside highly gifted teenage readers who have highly nuanced critical thinking skills, so, too, is our world made up of these individuals. And so too are our churches. As I struggle to create content that meets the need of challenging and engaging ALL types of students, I imagine our pastors also have an incredible task. Very often we teachers find ourselves “teaching to the middle,” as it were, hoping our highest achieving students are not getting bored, and then scaffolding for others. But as an educator, I ask myself the question: What am I losing by not pushing the rest of the class in the direction of my gifted students, who often are introverts, cultivating a life of deep thinking?

(But for some reason, our classrooms are places of these business models which do not place a heavy emphasis on quiet, personal inquiry and focused individual scholarship, and I am convinced we cheat our students because of this.)

How are we doing with engaging gifted Christians in the church? And what do we gain to lose by not making space for introverts in the church?

I contend that our churches, our church services, our Sunday schools and our Bible studies do not engage the type of deep thinking that so many introverts long for. And we’re culturally insecure about it, on all fronts. Introverted thinkers are insecure of their fresh visions, and extroverts, insecure about their own academic habits, make jokes about Biblical study being “too smart” for them.

However, I contend that if we do not make space for liturgy, for focused study, and for a tolerance of scholarship within the church, we risk silencing a significant 33 percent. We will be left with Christian thinkers who are disappointed by the intellectual life of the church, who are insecure about their God-given temperament, and who quietly shift their intellectual energy elsewhere. And that’s a shame.

Esther Swartzentruber is a Mennonite educator from the Ohio plains, whose English-teaching career has taken her from secular colleges in Kansas and Ohio to Mennonite high school English classrooms in northern Indiana and (most recently) Lancaster County, Pa. She writes at Shasta’s Fog, where this post first appeared.