“High levels of stress,” said a 2016 research brief by Pennsylvania State University, “are affecting teacher health and well-being, causing teacher burnout, lack of engagement, job dissatisfaction, poor performance, and some of the highest turnover rates ever.” Does teacher stress affect students? “When teachers are highly stressed,” the authors noted, “children show lower levels of both social adjustment and academic performance.” They identified, amidst other findings, that high turnover rates have been to linked to lower student-achievement and increased financials costs for schools.

Teacher burnout might be associated with student stress, suggested a Canadianstudy published in April. Researchers at the University of British Columbia retrieved saliva samples from several hundred students in grades four to seven and analyzed their cortisol levels, and they discovered that in classrooms where educators reported greater burnout, or emotional fatigue, the cortisol levels of the children were higher, according to a press release. “This suggests that stress contagion might be taking place in the classroom among students and their teachers,” said Eva Oberle, the lead author of the study.

American teachers, I recently discovered, report the most weekly hours of classroom instruction compared to their international counterparts—and given the lack of time during the school day for other essential things such as planning, assessing and collaboration, I assumed that the primary reason behind the high level of teacher stress was almost entirely time-related. But the more I looked into this question of why so many American teachers report high levels of stress, the clearer it seemed that an exceptionally full teaching schedule worked in tandem with another factor: an abundance of professional demands.

Last year, more than 30,000 teachers completed an online 80-question survey created by the American Federation of Teachers and Badass Teachers Association. The results showed, as covered by The Washington Post, that the majority of teachers reported high levels of stress and were “particularly anxious about having to carry out a steady stream of new initiatives—such as implementing curricula and testing related to the Common Core State Standards—without being given adequate training.”

“We ask teachers to be a combination of Albert Einstein, Mother Theresa, Martin Luther King Jr., and, I’m dating myself here, Tony Soprano,” Randi Weingarten, president of the American Federation of Teachers, told The Washington Post, which emphasized that the survey’s findings weren’t scientific. “We ask them to be Mom and Dad and impart tough love but also be a shoulder to lean on. And when they don’t do these things, we blame them for not being saviors of the world. What is the effect? The effect has been teachers are incredibly stressed out.”

Recently, a 25-year veteran U.S. teacher told Colorado Public Radio (CPR) he left the profession because he couldn’t handle a mountain of paperwork, related to expectations to document backward-designed lesson plans. “Everything’s very time-consuming. In my mind, it’s not productive time,” he told CPR.

“The district and national backers of this methodical planning,” reported Jenny Brundin of CPR, “say it creates the highest-quality classrooms, freeing teachers to teach what they want while giving them better-structured lessons and activities that push kids to think at a higher level and lead their own learning.” According to Brundin, the veteran teacher thinks this initiative started to drain him physically and mentally, and limited his creativity.

For many American educators, the current teaching arrangement appears somewhat grim: Schools expect a lot out of their teachers, without providing them with sufficient training and time during the school day to carry out their many roles and responsibilities.

A recent report (“A Coming Crisis in Teaching?”) by the Learning Policy Institute(LPI) investigated the teacher shortage that affects many class subjects and parts of the country, and found that “the most important driving factor of teacher shortages is high teacher attrition.” In fact, America’s teacher-attrition rates have remained around 8 percent since 2005, and they are, according to the report, nearly twice as much as they are in several high-performing countries, such as Singapore and Finland.

“The more teachers know about how to do their jobs well,” noted the LPI report, “the more they experience a sense of self-efficacy and derive satisfaction from teaching.” Indeed, one of the things that academic literature says people need in order to experience happiness, as The Atlantic’s Joe Pinsker recently pointed out, is “being good at whatever it is one spends one’s days doing”—or, in other words, a sense of mastery.

“[T]he system that we have right now in America, which is focusing on test scores and accountability, and has teachers being pulled in so many different directions at once, has got so many different pressures coming from so many different places,” said Mike Anderson, a veteran educator and the author of The Well-Balanced Teacher. “It’s almost like a recipe for making people feel incompetent.”

Anderson, an education consultant who travels the country meeting with American teachers, told me that he’s heard reports of “flavor of the month” professional development (PD) where a school shifts its PD focus every six months or so. Other schools are quick to adopt new curricula.

“So if you’re just getting your mind wrapped around the old math curriculum and suddenly the math curriculum changes and you’re back on the steep end of the learning curve,” Anderson said, “then we’re constantly putting teachers in this place where they never feel like they’re getting good at anything.” It leads, he explained, to a “lack of [a] sense of competence”; “it’s one of the biggest reasons,” he theorized, “why we have teachers burning out.”

What if—before embracing another hot, new educational initiative—U.S. school leaders asked themselves a very simple question: Will we provide our teachers with enough training and time to master that particular novel approach? It’s wise to remember, as Anderson put it, that “it takes years to get really good at something, to build your sense of competence.”