It is common to hear, for example, that when lectures and tutorials are over, Muslim students are forbidden by their families to fraternise with their peers. They can’t have a coffee in the canteen, much less go to the pub or a nightclub. Instead, they must go straight back to their parents.

If they do make friends, they are not allowed to bring them home. Their families refuse to permit any trace of the broader British community to cross their threshold: it has to be left on the doorstep.

So friends must be kept secret, which is often impossible when privacy in the family is banned. I know students who are not allowed even to talk on the phone at home without others listening.

One 18-year-old who told his family of his ambition to become an artist described his father’s reaction to me: ‘He slapped me across the face. Then he sent me away. He does not want to talk to me now.’