As someone who has been in school for his entire life, I've always noticed that the average girl typically outperforms the average male in my classes. But it seems like the distribution of males was much wider.

For example, if each gender's academic capabilities were normally distributed, then I would expect the mean for girls to be higher than the mean for boys, but the variance for boys to be larger than the variance for girls. I say this because I tend to see many boys at the very bottom of my classes, but also at the very top.

Of course this is all based on my experiences in school, and I have no data to back this up. But I'd be interested in seeing distributions of academic performance for each gender.