Mixed students and groups always perform better
replies(1):
https://www.kidsnews.com.au/humanities/study-reveals-benefit...
>The report, commissioned by the Alliance of Girls’ Schools Australasia, was conducted by Macquarie Marketing Group using OECD data
reads more to me like "we found that all-girl private schools are better than the average of public and private schools", and the obvious reason why is probably *because they're private schools*, and not because they're all-girl.
> there are some underlying factors skewing these results, such as: > * grammar schools are more likely to be single-sex > * co-educational schools have a higher proportion of poorer pupils > * girls are more likely to get good results
Also note that both of your comments show that people in a position to choose, are choosing single sex schools for their daughters and getting better outcomes on average.
Lastly, while the article mentions some caveats around selective state schools, the other side of that is the UK has many single sex comprehensive schools. We should not ascribe too much weight to the caveat.
Generally, in mixed-gender groups aged 13+, you will have some dating activity and a subsequent drama / bad blood from various heartbreaks and betrayals. Having to sit in the same classroom makes everything emotionally worse.
This is somewhat less of a problem if the same activites take place outside school and thus are less likely to complicate relationships within the class.