One girl said she'd always wanted to be a boy because they had more freedom and better job opportunities, and there were nods of agreement from both sexes - followed at once by female protests that it would be awful to change.
Why? I asked. Because, they said, boys are always getting into trouble. People expect them to. It's part of being macho.
The boys in the class made no attempt to deny this, but they shifted uneasily as they found themselves the objects of feminine compassion.
"They don't have the same sort of friendships as we do," one girl said. "They don't help each other," said another.
Asked to write about the first day's experience as a member of the opposite sex, the sympathy became even clearer.
Lisa wrote as if she was a boy-turned-girl. "In a small way I think I like itII 'm getting more attention and no boys are hassling me to play football, calling me a wimp or saying that I'm not macho.
"For once I'm quite happy with the boys in my class."
Jane was even more detailed in her empathy. As a boy, "I felt that I had to be tough, straighten my shoulders and put an almost angry face on. 'What's your name?' said a boy with a smirk on his face. 'None of your business,' I said rudely, almost instinctively, something I would never have done as a girl. I was definitely being more aggressive.
"I watched the other boys to see if they were the same. I saw a girl walk past, a boy kicked her, then he smiled. He seemed happy to be in trouble with the teacher. He liked the attention."
The boys were provoked into self-defence. James wrote that, as a girl, he would still be the same person inside and have the same level of intelligence, but would have to act like a different person. He also noted that "boys ask you out and you could fall pregnant".
Craig said: "Boys would comment on how I look, if nice or ugly. They would make very dirty remarks to me." He added: "I would not be expected at computing in lunch time because girls are rotten at computer games."
David, frowning over the difficulty of this unfamiliar task, was unable to define the causes of his feelings, but was in no doubt about their nature.
"As the day went on I felt worse. I really didn't like this at all.
"When it came to 3.30 I ran out of the school. I didn't like this and I was wishing that I could be changed back into a boy again so that I could do my old things and hang about with my old friends."
The stereotypes were dismayingly strong. A rigid picture was emerging of boys forced by the perceived male convention to be rough and to court trouble, and there was an unchallenged perception that adults strengthened this through their lower expectation of boys in behavioural terms.
As Donna wrote: "My mum wouldn't worry about me as much when I go out because I'm a boy, but she wouldn't trust me as much."
Julie picked up the same theme. "I walked through the corridors and immediately a teacher pulled me up for something I never even done. why's it always the boys?" Why, indeed? I go to countless schools through the Scottish Arts Council's Writers in Public scheme, and find the same gulf between boys and girls in their social behaviour.
An unconscious hint at the cause is implicit in the Victoria Drive writing. The children assume that boys are treated with less affection than girls.
Teachers may protest with good reason that boys need a firmer hand - but this merely confirms the self-fulfilling prophecy. The sexual stereotype may come from much deeper well-springs than those identified by Political Correctness.
Maybe we should ask whether our boys' aggression and resentment is that of people who do not know that they are loved.
Alison Prince is a writer living on the Isle of Arran.