"The girls living in some Middle Eastern countries, such as Bahrain and Oman, had, in fact, not scored very well, but their boys had scored even worse, a result found to be unrelated to either Muslim culture or schooling in single-gender classrooms," study researcher Jonathan Kane, of the University of Wisconsin-Whitewater, said in a statement.
This gender divide may be due to the type of schooling the boys get. Some of the schools are religious in nature, and contain few mathematics lessons. Many low-performing girls also drop out of school, so the data sets in these countries may be skewed, the researchers say.