BERLIN — The conventional wisdom is that we desperately need more male teachers. After all, according to a report on the gender of teachers in German schools, on average 85% of them are women.

Given that the report is now 10 years old, it's likely that the current number is even higher, because the representation of women in teaching has been rising steadily over the last century. In 1960, about 46% of elementary school teachers were women, but by 1990 they represented 67% of all German teachers. A similar trend has been tracked in other Western countries

Some education experts consider this so-called "feminization" of the teaching profession a real concern. They believe boys might perform better were they to have more male teachers.

When it comes to student performance, as a matter of fact, studies show that girls have overtaken boys. They tend to start school earlier, are less likely to have to repeat classes, and attend high school longer than boys.

Now, whether this is directly related to the domination of female teachers is unclear. There are indeed various studies trying to answer that question, but to date, they contradict one another.

Marcel Helbig, from Berlin's Social Science Research Center, has recently published an overview study that includes data from 42 surveys and 2.4 million pupils from 41 countries. His finding is that it makes absolutely no difference in student performance whether the boys have female or male teachers.

Girls don't particularly benefit from female teachers, and the same is true for boys from male teachers, he says. The teacher's gender simply doesn't matter at all, Helbig concludes.

"Therefore, there is no empirical basis for political programs claiming to resolve boys' education crisis with more male teachers," Helbig says. In fact, he says, girls have always performed better in the classroom. His investigation of 369 studies confirmed that between 1914 and 2011, there were no major changes in student performance between boys and girls.

He explains the phenomenon by saying the two genders have different kinds of motivation and commitment levels. Girls tend to be more disciplined and hardworking, which results in better grades.

"Self-discipline and the willingness to work hard in order to get good grades and are not part of men's typical gender concepts," Helbig says.

If and how the school plays a key role in this behavior remains an open question for the scientist. Maybe boys do need male teachers: not to settle any injustices, but as role models.