Girls outperform boys in educational achievement in 70% of the countries studied between 2000 and 2010 that analyzed 1.5 million 15-year-olds.[i] This holds true even in states with low gender equality ratings. Boys outperform girls only in Colombia, Costa Rica and the Indian state of Himachal Pradesh and among high-achievers. The achievement of boys and girls were similar in the US and UK. Overall, children think boys are academically inferior to girls and they believe adults share their perception.
Gijsbert Stoet and David Geary, “Sex Differences in Academic Achievement Are Not Related to Political, Economic, or Social Equality,” Intelligence, Vol. 48, 2015.