Alan McLean, who works with Glasgow City Council, was addressing the annual conference of the Scottish Parent Teacher Council in Edinburgh at the weekend. Its theme was "Kids Behaving Badly?" - with a strong emphasis on the question mark.
"We regard the question mark as extremely important," Judith Gillespie, the SPTC's development manager, said, "because we don't take it as agreed that kids are behaving badly. The prosecutor and judge as to whether kids are behaving badly are the same people."
Mr McLean, whose specialist work is in engaging and motivating learners, commented: "I have been working in behaviour management for 25 years and a 'crisis' in behaviour has been a feature of every year in my career.
"If that had been cumulative, there would be chaos out there - and we don't have chaos. In fact, schools are havens of tranquillity for many youngsters and I often feel that, if it wasn't for primary schools and the police, Glasgow would be in serious difficulty."
David Cameron, head of education in East Lothian, agreed that kids were now behaving differently, and sometimes "appropriately", when they are seen as behaving badly. "The view that kids' behaviour was getting worse was prevalent in 1972 when I started teaching," Mr Cameron said. "Is it perhaps now a case that the profession is ageing and that its sense of disapproval is stronger?"
He added: "We are encouraging young people to ask questions, not to take things at face value and to challenge. So is it surprising that we now have a generation of kids who don't accept what they are told?"
Mr Cameron said behaviour often reflected circumstances. "If you were looked after, or abused, or not part of a functioning family, or not loved or supported, what would you do? Wouldn't you behave badly?" Bad behaviour was often a protest.
He called for a better understanding of behaviour and for earlier intervention to tackle underlying problems. "Very often, behaviour deteriorates because of changes in a young person's circumstances," Mr Cameron said.
"We have strategies to deal with behaviour as problems develop but what we need are strategies to tackle them before they develop. We have maximum intervention for behaviour at the latest possible moment, and we need to turn that around."
Mr McLean said the priority for schools was to "move up a gear" and start motivating behaviour rather than just managing it. "Managing behaviour is really just like training the family pet - rewarding good behaviour and punishing the bad, manipulation and control. That is not good enough any more."
Mr Cameron and Mr McLean both agreed it was now critical to engage pupils who have switched off learning, but who may not be behaving badly - those Mr McLean described as the "quietly disengaged".
Mr McLean points to a recent review by the National Academy of America which endorsed this and suggested that classrooms will only engage learners if they nurture three factors - "I belong" feelings, "can-do" beliefs and "want to" attitudes.
He told The TES Scotland: "A sense of connection with the school is crucial. When pupils get involved in extra-curricular or after-school activities that provide a venue where they can relax and show what they can do, they are more likely to develop a sense of loyalty to the school. So efforts to promote social engagement are worth while."
Good teachers energise and re-charge children, Mr McLean said. But schools must recognise that "if authority is threatening, it's not authoritative but becomes authoritarian; that ethos has to change".
Mr Cameron stressed the importance of working with parents, who knew their own children best, and not getting involved only when children behaved badly.