There were also “negligible changes” in the well-being of pupils who took part in the mobile phone pouch pilot, though there was “some decrease in self-reported anxiety and depression symptoms,” according to the study.
The research team from KCL called on teachers and school staff to restrict their own smartphone use in school in order to be role models for pupils.
They also said that schools should consider letting older pupils use their phones more for study.
Stephen Moore, the principal of one of the schools in the study, said their school-wide ban had encouraged “young people to interact with each other”.
“I think there are very few schools that implement a ban on phones and then go back to having phones,” he said.
“I think the benefits far outweigh any disadvantages there might be.”
Moore added: “I think pupils have been quite receptive to the new rule and we’ve certainly encouraged them to interact with adults and sort problems out for themselves.”
Smartphone use in schools has been described by some principals as the “most serious issue facing schools in a generation”.
One head teacher said smartphone use was “affecting the development of children’s brains as well as their well-being”.
And over recent years, individual schools have introduced policies on the matter; many ban phones during class time and require parents to call reception if they need to contact their children.
Some have expressly banned smartwatches and smart glasses too.