Schools in England are "great forces for social cohesion", according to the head of watchdog Ofsted.
Sir Michael Wilshaw said schools were the places where different communities integrated and "provide the glue that helps hold our society together".
Sir Michael said in a speech that it was a great achievement that the children of immigrants performed so well academically in England's schools.
This was not the case in other European countries, he stressed.
"In many countries they [the children of immigrants] do worse than the children of non-immigrants," he told the annual conference of the Freedom and Autonomy for Schools National Association.
"In Germany, France, Finland, Italy and Switzerland, for instance, children of immigrants do far worse in school than their native peers.
"Not so in England. Our schools are remarkable escalators of opportunity.
"Whatever cultural tensions exist outside of school, race and religion are not treated as handicaps inside them. All children are taught equally. And contrary to tabloid claims, non-immigrant children do not suffer - rather the reverse."
"Schools, it turns out, are great forces for social cohesion. Yet nobody talks about it," he told the conference, which lobbies for self-governing schools.
"We are so used to picking over problems that we forget to notice what an incredible achievement this is. Most other countries aren't as fortunate.
"Schools are the place where different communities integrate. Schools provide the glue that helps hold our society together."
In the speech, Sir Michael said there had been huge improvements in the comprehensive school system in the past few decades.
"Let me be clear - for all their faults, our schools have improved immeasurably."
But he warned that serious shortcomings - such as the achievement gap between rich and poor pupils and a growing geographical divide in standards between the North, the Midlands and the South - had led some to conclude that the system was "broken".
"Comprehensive schools, they earnestly believe, have failed," he said.
But Sir Michael argued that a return to a grammar school system would be a "monumental mistake".
"For the country as a whole, selection at the age of 11 is simply not the answer."
He suggested that part of the reason that grammar schools were "back in vogue" was because of a failure to fully reform comprehensive schools.
"Two years ago... I warned that those who were resisting reform, who were refusing to embrace greater diversity in our school system - academies and free schools - would inevitably pave the way for the return of selection. And so it has proved."