The research, led by Dr Gülseli Baysu, focused on 2018 PISA data – a set of internationally accepted tests. This included the scores of 445,534 pupils in 16,002 schools across 60 countries.

The study is the first large-scale, multi-country study of its kind. It highlights that when 15-year-old pupils think that there is discrimination in their school, their scores are lower on the standardised tests for both maths and reading.

Researchers found that 25 per cent of the pupils thought their teachers were discriminatory some of the time or more of the time. These students were up to one year behind other students who reported low or zero levels of discrimination. 

For pupils who reported their teachers to be discriminatory all of the time or almost all of the time (1.5 per cent) the academic outlook was even worse – they were up to two years behind with reading and maths.

Dr Gülseli Baysu explains:

“To put it simply, our research found that when pupils report that their teachers are prejudiced, hold negative stereotypes, and say negative things and blame other cultural groups, their academic performance is worse."

The trend of lower academic performance being associated with perceived discrimination was the same for all pupils, regardless of their ethnic background or socio-economic status. However, students from a minority background perceived more discrimination within their schools.

Dr Baysu adds:

“This means that discrimination against ethnic minorities can have an impact on all students, including those who are not the targets of discrimination. So, in schools with a high discriminatory climate, academic performance of all pupils is lower.”

She and her colleagues from the KU Leuven, Belgium and The University of Amsterdam, The Netherlands (Agirdag & De Leersnyder) also investigated the psychology behind this.

Dr Baysu explains:

“We examined two psychological mechanisms that may potentially explain the association between discriminatory school climate and academic performance. This was the pupils’ sense of belonging and their attitudes towards learning. We found that when adolescents perceived a discriminatory school climate, they reported lower school belonging and attached less value to learning and effort and this was then associated with lower performance.”

It is hoped that the findings will show the benefits of practising and communicating a zero-tolerance policy against discrimination in schools.

Dr Baysu comments:

“These findings suggest that schools can protect adolescents from these adverse outcomes. They can promote both the well-being and achievement of all pupils by creating and maintaining a positive school climate that welcomes and respects ethnic-cultural diversity.”