The term “introversion” can mean a variety of different things in different contexts. Carl Jung defined it as an orientation through “subjective psychic contents,” while Scientific American contends that introversion is more aptly described as a lessened “sensitivity to rewards in the environment.” It’s generally accepted, however, that as Stephen A. Diamond gracefully describes it, “[Extraversion and introversion] are two extreme poles on a continuum which we all occupy.”

The most common use of the term is to differentiate between introverts (who are energized by quiet space, introspection, and deep relationships and are exhausted by excessive social interactions) and extroverts (who are energized by social interaction and external stimulation and tend to be bored or restless by themselves) as a way of explaining different personal reactions to similar contexts.

It’s in this sense of the word that some teachers are citing their introversion as a reason why today’s increasingly social learning environments are exhausting them—sometimes to the point of retirement.

After 11 years of teaching English at a public high school, Ken Lovgren left the profession, mostly because he was drained by the insistent emphasis on collaboration and group work. Engaging in a classroom that was “so demanding in terms of social interaction” made it difficult for him to find quiet space to decompress and reflect. “The endless barrage of ‘professional learning community’ meetings left me little energy for meaningful interaction with my kids,” he told me. “I suspect a lot of teachers feel as I do.”

In fact, it was easy to find other teachers who cited their introversion as a key reason they decided to leave the K-12 classroom. John Spencer, a former middle-school teacher who has written about the struggles of an introverted teacher, is now teaching at a university. “It’s easier to be a professor as an introvert,” he said. “There’s so much silence and solitude built into it.”

And Jessica Honard, the author of the book Introversion in the Classroom: How to Avoid Burnout and Encourage Success, told me that she left the teaching profession because she never had the time to recharge after constant exposure to such a stimulating environment. Claiming that she’s known many other teachers who have left because of exhaustion, Honard primarily blamed a lack of awareness and understanding of introverted personality types. She explained: “It’s a constant bombardment of social stimulation, and most teachers simply are not taught how to cope with it.”

In some ways, today’s teachers are simply struggling with what the Harvard Business Review recently termed “collaborative overload” in the workplace. According to its own data, “over the past two decades, the time spent by managers and employees in collaborative activities has ballooned by 50% or more.” The difference for teachers in many cases is that they don’t get any down time; they finish various meetings with various adults and go straight to the classroom, where they feel increasing pressure to facilitate social learning activities and promote the current trend of collaborative education.