Grammar schools have virtually no effect because genetics determine academic success, a King’s College London (KCL) study has found.

Researchers examined the genetic differences between students who attend selective and non-selective schools, then analysed their GCSE results.

They found that children who attend grammar or private schools are more likely to do well in exams - but this is largely down to their genes, rather than their school environment.

The study, published in the journal npj Science of Learning, suggests that the type of school a child goes to has little impact on their academic achievement by the age of 16.

Emily Smith-Woolley, the lead author of the paper, said: “Our study suggests that for educational achievement there appears to be little added benefit from attending selective schools. While schools are crucial for academic achievement, the type of school appears less so.”

She added that teachers and schools should be more open to discussing the role of genetics in the classroom, and the effects it has on educational attainment. Professor Robert Plomin, another of the paper’s authors, said that genetics should be included in teacher training courses.