Last year’s school results show that girls at single-sex schools outperform their co-educated peers.
This is despite recent comments by Richard Cairns, head of Brighton College, that pupils at all-girl schools could be at a “huge disadvantage” in later life as they had not socialised with boys.
Analysis of 2015 academic results by education website SchoolDash said 75% of pupils at single-sex schools achieved five good GCSEs (including English and maths), compared with 55% at mixed schools.
All-girl secondary schools also outperformed those for boys.
The research looked at results for England’s 378 mainstream single-sex state schools, including 161 which are all-boy and 217 all-girl.
Around a third are grammar schools.
The analysis showed the advantages for girls-only schools held true even when results were adjusted for other factors, such as social background and selective intake.
Single-sex school pupils from poorer backgrounds outperformed those at mixed schools.
61% of disadvantaged students at all-girl schools gained five good GCSEs compared with 55% in “similar” mixed schools and just 38% across all mixed institutions.
SchoolDash founder Timo Hannay said: “The overall picture that emerges is one in which single-sex secondary schooling for girls does seem to have some benefits, at least when it comes to these particular measures of GCSE performance.
“Though it’s less clear cut, the same may also be true for poor and/or underachieving pupils – ironically the target groups that single-sex schools tend to avoid.”