The best teachers do more than explain a lesson. They create an environment where students feel engaged, confident and motivated to learn. New international research suggests that one often-overlooked factor may help make that possible. What is it? The teacher's own emotional state.

A recent study found that teachers who enjoy their profession tend to provide higher-quality instruction, while teachers who frequently experience anger in the classroom are more likely to struggle with teaching effectiveness. Those differences, researchers found, can directly affect students' confidence, interest in learning, as well as their academic performance.

“We wanted to understand this full chain of events connecting how a teacher feels to how a student performs.”

The research was led by Marina Elena Pfeifer, PhD, with colleagues at Ludwig Maximilian University of Munich, Germany, and those from the Leibniz Institute for Science and Mathematics Education and Humboldt University of Berlin.

The study analyzed data collected through the OECD's Global Teaching Insights Study. OECD is an international research project that provides a direct look into classroom instruction by videotaping and analyzing math lessons across eight countries and economies.

To understand how teachers' emotions influence student outcomes, the researchers examined data from the same mathematics lesson being taught by 679 mathematics teachers to more than 17,500 students in eight countries: Chile, China, Colombia, Germany, Japan, Mexico, Spain and the United Kingdom. This allowed the researchers to compare classrooms across different cultures and educational systems.

Teachers were asked to report how much they experienced enjoyment and anger while teaching. Students evaluated the quality of their teachers' instruction, rated their own confidence and interest in mathematics and completed a performance test.

To evaluate teaching quality, the researchers looked at three measures: classroom management, how supportive teacher-student relationships were and how well the teaching encouraged students to think deeply and critically.

The idea was to better understand the connection between teachers' feelings and students' success. “We decided to conduct this research because teaching is not only an intellectual activity but also an emotional one,” Dr. Pfeifer said in a press release. “We wanted to understand this full chain of events connecting how a teacher feels to how a student performs.”

They found that emotions can set off a chain reaction in the classroom. Teachers who reported greater enjoyment were more likely to manage classrooms effectively, build positive relationships with students and use teaching approaches that challenge students intellectually.

Students in those classrooms tended to report greater confidence in their abilities, stronger interest in learning and better test performance.

The opposite pattern emerged when teachers reported higher levels of anger. These teachers generally received lower ratings for teaching quality, and their students showed less favorable outcomes.

“Teaching is not only an intellectual activity but also an emotional one.” And emotions can set off a chain reaction in the classroom.

One of the most interesting findings involved the consistency of the results across cultures. “The most fascinating part for me was the cross-cultural similarity of our findings,” Pfeifer said. “Despite considerable cultural, economic, and linguistic differences, the mechanisms by which a teacher's emotions shape teaching quality and student outcomes remained remarkably similar across the globe.”

The researchers also uncovered a somewhat unexpected finding. Stronger teacher-student relationships were sometimes associated with lower student performances. Rather than suggesting that supportive relationships are harmful, Pfeifer believes the finding likely reflects the fact that teachers often provide additional emotional support to students who are already struggling academically.

It's important to note this study does not prove that emotions alone cause better or worse outcomes. However, it adds to growing evidence that a teacher's emotional well-being is not simply a personal matter; it may be an important ingredient in effective education.

For parents, students and school leaders, the message is straightforward: Supporting teachers may ultimately support students as well. Efforts to reduce workplace stress, prevent burnout and help educators manage difficult emotions could benefit not only teachers themselves, but also the young people they teach.

The study is published in the Journal of Educational Psychology.