Differences between schools?

Are different types of pre-university education associated with different mental health outcomes? 

Given the concern expressed about the incidence of poor student mental health at university it is reasonable to assume that more research would be available on the relationship between the different routes taken to reach university and subsequent mental health outcomes. Unfortunately, this does not appear to be the case. 

However, there are two areas where some material is available. Firstly, issues related to mental health in state schools compared with independent schools. Secondly, considering single sex and co-educational schools, comparing different outcomes particularly for girls – although these ‘outcomes’ tend to focus on academic achievement rather than well-being. 

State versus Independent Schools 

While the issue of poor mental health in schools is a concern very few peer-reviewed studies consider the differences according to school type. There are many studies that focus on how the problem of mental health emerges in secondary schools. However, the focus here is primarily on the state sector, with no comparison with independent schools. 

For example, the study by Jerrim (2021) provides evidence of a rapid increase in mental health issues moving from primary into, and through, secondary levels. This appears to be driven by age and not any particular experience at school. Notably, there is evidence of a gender effect, with girls experiencing a more acute increase in problems compared to boys, suggesting that gender is an influencing variable. Wright et. al. (2020) also found that gender is relevant, with girls having a higher incidence of emotional problems, while boys exhibit behavioural issues. Age appears to a relevant issue here too. 

There are limited studies which address the link between attending an independent school and a variety of outcomes. Sullivan et al (2020) look at attendance during adolescence and the presence of psychological distress at ages 16 and 42. This is a useful longitudinal study, which suggests that private schools do not necessarily confer an advantage in terms of mental health. However, this data is based on secondary schools during the 1980s, and therefore the findings may not necessarily apply to private schools today. Both private and state schools no doubt pay more attention to the mental health of their current pupils than they did for past generations of young people. The authors conclude that schools which are academically successful do not necessarily provide wider benefits in terms of mental health. 

The study by Henderson et. al., (2022) stands out for its direct emphasis on how school type influences non-education outcomes. Because the advantages of attending independent schools are most often couched in terms of educational attainment this study makes a significant contribution. This study is also longitudinal and aims to measure satisfaction with life and mental well-being at 3 main points. The results indicate no evidence of a strong, statistically significant private school advantage (or disadvantage) regarding the reporting of mental ill health symptoms at age 14, 16 or 25 for either men or women. These results hold whether controls are included in the model or not. This finding repeats the conclusion of Sullivan et al. (2020), who found that private schooling confers no wider benefits in terms of mental health using a cohort of people born in 1970. 

Conversely, A 2017 study conducted by the commercial company AQR International is mentioned frequently in the independent sector. This study is based on the psychometric ‘mental toughness’ testing of students in independent schools and finds that compared to students in state schools they perform slightly but statistically significantly better. This construct, it is suggested may lead to greater resilience and by implication better long-term mental wellbeing. 

Materials produced by independent schools tend to recognise the widespread existence of poor mental health that is associated with the state sector but they define their own situation as different e.g. only 6% of surveyed headteachers reported that mental health problems were a significant factor in behavioural and mental health problems compared to 25% from state schools in one report (Taggart et al. 2014). This is probably not surprising as young people from disadvantaged backgrounds are known to have a higher prevalence of mental health conditions and the proportion of disadvantaged pupils in independent schools is likely to be significantly lower than in state schools.

Websites which promote independent schooling use mental health provision as part of their ‘offer’ to prospective parents. This implies that they take a different approach compared to mainstream schools and are able to provide a higher level of proactive support which prevents issues from becoming more problematic for students. This contrasts markedly to a perspective expressed by some working in state education where an emphasis is placed on the steady increase in mental health problems that have occurred as state funding has decreased. The problem is constructed as one of diminishing resources.

Single Sex versus Co-educational 

When single sex schooling is advocated, it is usually done so for the perceived benefits it delivers to girls. These benefits however are usually defined by level of academic achievement and pursuit of less stereotypical subjects. However, in a review of literature Smyth (2010) points out that when assessing outcomes, it is very difficult to compare the effects of schooling type due to the more selective intake criteria of many single sex schools which apply in both social and ability profiling. Single sex education is more often delivered in independent schooling settings. His review reveals: no significant differences for gender achievement in single-sex vs co-ed; that in UK single-sex schools girls tend to take less traditionally gendered subjects; a general consensus that boys and girls in co-ed settings self-report more positive development but across more complex measures results show no advantage between single sex and co-ed; no difference in adult literacy/numeracy or employment. Therefore, there is very little consensus regarding advantages of single-sex education for academic achievement apart from some evidence for girls taking less stereotypical subjects.

An article published in Science argues strongly against single-sex education, stating that the claims promoting this approach is superior to co-educational approaches are based largely on ‘pseudo-science’. Halpern et. al., (2011) assess sex-segregated schooling in the USA (not the UK) but the findings again highlight the intersection of single sex education and selective schools. The authors conclude the evidence for the superiority of single sex education doesn't hold up, because where outcomes appear better this is due to single sex schools being more selective. Although excellent public single sex schools clearly exist, there is no empirical evidence that their success stems from their single sex organization, as opposed to the quality of the student body, demanding curricula, and many other features also known to promote achievement at coeducational schools; no evidence of brain structure based sex differences in learning to justify segregation; segregation doesn't counter sex stereotyping but instead makes gender seem more salient; and there is no convincing arguments that some students would benefit from single-sex education.

One Master’s thesis (Chowdhury, 2010) presents an extensive literature review, which examines a series of debates regarding the relative advantages of both single sex and co-educational approaches. The author highlights that there is a gap in understanding outcomes which she summarises in the concept of ‘self-esteem’. ‘Self-esteem’ is understood and constructed through 9 sub-scale components comparing single sex and co-educational schooling. The research has identified that there are some differences between the self-esteem of those attending single-sex compared to co-educational schools, taking into consideration that other environmental and situational factors will play a part e.g. the effect of family. What this study does find is that single-sex schooling does enable higher levels of self-esteem across some of the subscales, primarily on scholastic competence, highlighting and placing value on their existence. What is also apparent is that pupils with high self-esteem can also be found in co-educational schools, and therefore our attention should arguably be focused on how to encourage and increase numbers of these types of pupils in these schools and decrease the gender divide. Whether this may be through single-sex classes within co-educational schools, is a matter that is still being investigated.

A 2021 meta-analysis by AQR (a commercial company that administers psychometric tests and provides training programmes to increase performance) was reported at an event organised by the Girls Schools Association GSA) in summer 2021. The GSA reported, ‘It analyses the responses of girls in single-sex Girls’ Schools Association (GSA) schools, compared with girls in other schools. The findings indicate that girls in GSA girls’ schools generally possess higher mental toughness scores than girls in state and independent coeducational schools, particularly for emotional control and confidence. The GSA girls in general have greater commitment, greater control – particularly emotional control – as well as greater confidence, both in terms of confidence in their abilities and their inter-personal confidence’. These findings were repeated by a number of independent schools but the meta-analysis itself does not seem to be in the public domain, making further analysis difficult.

It should be remembered that many of the suggested advantages of single sex schooling for girls are difficult to disentangle from the fact that many girls’ schools are selective independent schools, making genuine comparison with girls in state schools difficult, as they come from a wider range of backgrounds and abilities. It would be helpful to know how the mental toughness scores for girls in state and independent co-educational schools broke down, to ensure the AQR analysis was comparing like with like.

Independent schools which are single sex draw on a discourse of wellbeing alongside academic achievement to promote their approach to girls’ education in particular. This claim is based regularly on the AQR ‘mental’ toughness’ study mentioned earlier, which is not peer reviewed. For example, the website for the Girls Schools Association highlights the AQR research on their website saying, "New research indicates that girls who attend single-sex girls’ schools are generally more confident and more emotionally in control than girls in coeducational schools." However, other websites such as The School Run which is an educational resource and arguably more objective states the there is no conclusive evidence to suggest independent schools are better for girls and discusses a range of pros and cons. Other websites such as Shout OUT UK emphasise the negative effects of single sex over co-educational approaches.


On the evidence available it is difficult to draw any definitive conclusions as to whether different types of pre-university education are associated with different mental health outcomes.

State schools do appear to engage differently with the problem compared to Independent Schools and highlight it as an issue that is on the increase in their settings, whereas independent schools tend to present a more positive picture. Stakeholders with distinct interests will tend to position themselves in relation to the issue in contrasting ways. The most useful evidence probably comes from two peer reviewed longitudinal studies that find no advantage for independent schools versus state schools when it comes to mental health.

Differences between mental health in single sex compared with co-educational schools have been the subject of limited research. One Master’s thesis found some limited evidence of higher reported self-esteem amongst students in single sex schooling. One of the most influential sources of evidence used to promote independent girls’ schools comes from a study by a commercial company AQR who have found higher levels of ‘mental toughness’ in girls attending independent schools - but this is not based on a peer reviewed study. Published research suggests that this debate is far from resolved. The conflation with single sex education and selectivity is a particularly important confounding factor here.

Shelley Budgeon, August 2022