In the United States and elsewhere, PLCs are designed to facilitate professional development through discussions in which teachers share their best practices and what they have learned through their experiences in the classroom.

"Teachers can feel fairly isolated in the classroom," Goddard said. "PLCs help teachers build a sense of community and learn from each other about how to improve classroom instruction."

In China, the equivalent of PLCs is called Teaching Research Groups (TRGs). The leaders of TRGs are experienced teachers who are not traditional administrators, but do serve as supervisors and coordinators and are involved in teacher evaluations, lesson planning and teacher selection.

This study involved 537 teachers from 238 TRGs in a variety of both urban and rural schools in China.

Teachers rated their TRG leaders on three dimensions of humility: their willingness to view themselves accurately, such as admitting when they didn't know how to do something; their appreciation of others' strengths; and their teachability, such as being open to other teachers' advice.

Results showed that teachers who rated their TRG leaders as being higher in humility were more likely to report that they shared their knowledge and expertise in TRG meetings.

"The whole point of these groups is for teachers to share their knowledge, so the fact that humble leaders inspired individuals in their groups to be more willing to do this is very significant," Goddard said.

The study also found why humble leaders were so effective in helping their teachers share their knowledge.

Results showed that in TRGs with humbler leaders, teachers reported higher levels of psychological safety - they felt they could take risks and knew that others would not act in a way to undermine their efforts.

That feeling of safety led them to feel more psychologically empowered: They felt their jobs had meaning, they had autonomy to do their work, and they felt they were competent and that their work had impact in the school.

So humble leadership led to teachers feeling psychologically safe, which made them feel empowered and ultimately led them to share their experience and knowledge more fully with their colleagues, Goddard said.

"This feeling of teachers that they could safely share their knowledge comes from having a leader who has humility, an openness to learning from others, a willingness to revise opinions, and an appreciation for the strengths of others," he said.

While this research was done in China, Goddard said he believes the results would be similar in the United States and elsewhere.

"There's a lot of evidence that suggests trust is a key part of successful organisations. And feeling psychologically safe and empowered to share your knowledge in the workplace is part of building trust, and that's what humble leaders help create," he said.

"That is as true in the United States as it is in China." In the same way, the results should be applicable outside of education.

"Many of the same principles that make successful organisations cut across cultures and fields. It makes sense that humble leaders will build trust and better relationships that will increase the effectiveness of any groups that have to work together," Goddard said.