By Gary Eason
BBC News Online at the NASUWT conference
Pat Lerew was also concerned about the impact of the media
The "devil take the hindmost" legacy of Thatcherism has contributed to a rise in aggression and bullying in schools, a teachers' leader has said.
Modern parents were "Thatcher's children", who were at school "when there was no such thing as society and it was everyone for themselves", said Pat Lerew, president of the NASUWT.
Teachers in the 1980s were seen as "failures in the success race", she told the union's annual conference, in Llandudno.
Mrs Lerew said: "Small wonder then that the children of the day grew up with attitudes that have now manifested themselves in their own children.
"This drive to be first and the devil take the hindmost attitude has bred an inevitable rise in aggression and bullying."
Her theme was that pupil behaviour was proving "the hardest nut to crack" now that teachers' workloads and pay were being tackled.
Her union has been highly active in schools in holding industrial action ballots to back up teachers' refusal to teach disruptive pupils.
Mrs Lerew said this was happening "with increasing regularity".
But what saddened her "even more than the violence" was the low turnout - with teachers who could not be bothered to support their own colleagues.
Equally upsetting were governing bodies which overturned head teachers' decisions to expel a pupil.
The media had reflected the rise in aggression, with violence "the norm" in too many films and television programmes and antisocial behaviour considered "cool", she said.
As a result the yob culture continued and there was increasing use of weapons.
Childhood was also being "eroded" by the media - particularly by advertising, she added.