An international study has found that girls outperform boys in educational achievement worldwide.

In 70 percent of the countries studied - regardless of the level of gender, political, economic or social equality – girls come out on top.

“We studied the educational achievement levels of 1.5 million 15-year-olds from around the world using data collected between 2000 and 2010,” said researcher David Geary.

“Even in countries where women's liberties are severely restricted, we found that girls are outperforming boys in reading, mathematics, and science literacy by age 15, regardless of political, economic, social or gender equality issues and policies found in those countries.”

According to the data, boys fell behind girls in overall achievement in reading, mathematics, and science in 70 percent of the countries studied, with boys outperforming girls in only three areas: Colombia, Costa Rica and the Indian state, Himachal Pradesh.

Surprisingly, in countries known for relatively low gender equality ratings, such as Qatar, Jordan and the United Arab Emirates, the educational achievement gap is quite large and actually favours girls.

“With the exception of high-achievers, boys have poorer educational outcomes than girls around the world, independent of social equality indicators,” said Gijsbert Stoet, reader in psychology at the University of Glasgow.

“Results show that a commitment to gender equality on its own is not enough to close the achievement gaps in global education; the gap is not increasing.

“Although it is vital that we promote gender equality in schools, we also need to make sure that we're doing more to understand why these gaps, especially among boys, persist and what other policies we can develop to close them.

“The data will influence how policymakers think about the options available,” said Geary.

“For example, to increase levels of equal opportunities in education. We believe that policymakers and educators should not expect that broad progress in social equality will necessarily result in educational equality.

“In fact, we found that with the exception of high achievers, boys have poorer educational outcomes than girls around the world, independent of social equality indicators.

“Therefore, in order to effectively close the gaps in achievement, education policymakers should consider factors other than political, economic and social equality, and especially as related to boys' overall achievement and high-achieving girls' interest in mathematics and science.”

The study, ‘Sex differences in academic achievement are not related to political, economic or social equality’, was recently published in the journal, Intelligence.