There is a widely accepted understanding that girls do better in girls’ schools. At The Abbey we hear this expectation from prospective parents all the time, and that is clearly one of the reasons why our families have chosen single-sex education.

Unsurprisingly there are those on the other side of the argument! They point to complexity and nuance in the evidence base and suggest that there are many other factors explaining the predominance of girls’ schools at the top of league tables.

However, the more this is studied, and more importantly, the more it is experienced, the more clear the benefits become. The most recent research, by FTT Datalab, looked very hard at controls, and sought to eliminate all possible variables that might explain why girls do better in single-sex – from the background of students, to prior ability, to type of education on offer. Once they had done that, a clear and significant advantage remained.

The obvious question is – why? Some have sought to explain this by suggesting negative factors may push girls onwards: intensity and competition – the old idea of ‘hot-housing’. But spend ten minutes in any girls’ school – I’ve worked in two and visited dozens – and this argument simply makes no sense. You hear more laughter and see more collegiality in girls’ schools than anywhere else. That’s why we encourage parents considering The Abbey not just to come to open events, where activities are organised for them, but to visit the school on an ordinary day, poke their heads into lessons, and watch a lesson change.

What parents report from that experience is two things, which seem contradictory, but are in fact wonderfully complementary. They say it is so calm, and so full of buzz. Calm because there is a sense of engagement, interest, appetite to learn. Girls listen to each other and to teachers, and question with heart and sincerity: they lean in to learning. And buzzy because from groupwork to the lunch queue, the energy fizzes and crackles with wit and ideas and humour and enthusiasm.

All of which forms the very obvious answer to the question why. Girls are doing better because they are in a space where they feel valued and they value each other; where they are free to be themselves, and where the self-consciousness and sense of judgement of teenage years is minimised. Head teacher Kat Pugh put it beautifully in a Guardian article looking at the latest research: girls’ schools provide ‘a culture of achievement and a sorority in which girls celebrate and enable each other’s achievements and can feel proud of doing well academically without inhibition’. Or as Cheryl Giovannoni, head of the Girls’ Day School Trust, puts it: ‘girls are given the space they deserve’.

Girls’ schools are in my experience the most joyous, lively and energetic spaces to learn. But for all the brilliant experiences they offer during a student’s time in school, what matters even more is the lifelong impact. Previous research looked at what happened afterwards, and found that students from all-girls’ are more assertive and more likely to be heard in mixed environments after they graduate. Girls’ schools are not a retreat from or a denial of a co-ed world: they are the best preparation that exists anywhere to thrive in a co-ed world.

The most heartening proof, and most compelling answer to the question of why girls’ schools exist, may be found in our alumnae events. That’s where we see the benefit of learning, for sure, and without self-doubt, that your own voice matters and will be heard. Alumnae are wonderfully diverse in what they do and how they are in the world: but the atmosphere remains one of enthusiasm, clear-eyed interest in and care for the world and each other, and a powerful, grounded assurance. It is hard to imagine a room with less arrogance or more warm, engaged confidence. Witnessing the outlook on life of our students, past and present, is a huge privilege – and a source of boundless hope for their, and our, futures.

Will le Fleming, Head