Also girls and boys learn differently, boys more visually, girls are better at verbal and written learning. This gives an obvious advantage in most classrooms.
In addition to learning different, the mind works different. Girls all through life (not just the school years) are better at communication in most cases (I even think this has been shown in brain scans, a woman's brain is more active during conversation than a man's), again this is something helpful in a classroom setting so it is an advantage.
Guys are better at some aspects in general. The Male mind for instance generally is better wired for math because of the difinitive nature of numbers - though god forbid this be pointed out lest a feminist start a petition or something.
None of these rules are set in stone though. Some guys are excellent communicators, some women are excellent in math, but as a general statement it is fair to say females are better students all around.
Indeed it is a fact that women have overtaken men at almost every level of education in developed countries around the world. Many factors have contributed to this namely;
1. The role of parents -----> Parents prefer to read books and play educational indoor games(Ex : Scrabble) with their daughters while they practice outdoor sports(Ex : Football) with their sons. So boys, since their early age are not inserted into the educative sector.
2. Boys take more time to mature and develop than girls ----> Research have shown that overall intelligence between boys and girls are the same. But if you look at the ability of someone to perform well in a timed situation, females have a big advantage. One theory points to differences between the brains of boys and girls. While girls'