Too many children are waited on hand and foot, and treated like "little Buddhas" by their parents, Dr Mary Bousted said today.
Children need boundaries and society needs to be more confident teaching youngsters what is reasonable behaviour, the general secretary of the Association of Teachers and Lecturers (ATL) said.
She warned that problems with poor behaviour are not confined to the working classes, with some middle-class parents buying their children off rather than setting limits.
Dr Bousted, who is due to address the ATL annual conference in Manchester later today, said: "It seems to me that far too many children are waited on at home hand and foot.
"They don't do the washing-up, they don't do the hoovering. It doesn't do them any favours if you make them little Buddhas at home, and it certainly doesn't do them any favours in school."
She added: "Children need boundaries in order to feel safe and children without boundaries at home resent boundaries being imposed at school.
"We need to be more confident as a society in saying 'you can go so far, but no further', 'you can have this, but not that'. We need to be more confident in what's reasonable and in our expectations of children and young people."
Children who have not been set boundaries do not understand their responsibilities towards other people, Dr Bousted suggested, and fail to understand "that adults are not there to serve them, they're there to safeguard and teach them".
She warned that lack of boundaries is "not a problem that's confined to one class" and that middle-class parents, if they fail to impose limits, "can buy off their children".
Dr Bousted said that the vast majority of parents and children do a good job on setting boundaries and civilised behaviour but added: "The effect of the minority is utterly disproportionate."
Her comments come the day after ATL passed a resolution warning that schools need tough behaviour sanctions that rival corporal punishment as a deterrent for naughty pupils.
Current methods, such as detention, suspension and exclusion, are failing to deal with behaviour problems because school leaders are more concerned with meeting targets and losing income, according to Julian Perfect, an ATL member from inner London.
He insisted he was not advocating a return to corporal punishment.
At the group's annual conference in Manchester today, Mr Perfect proposed a resolution which warned that successive governments have failed to introduce effective ways of dealing with naughty pupils since corporal punishment was abolished in 1986.
The forms of discipline currently available to teachers remain "totally inadequate", the motion said.
Mr Perfect told delegates: "This motion does not seek the reinstatement of corporal punishment but rather the identification of additional forms of sanction for use by teachers to deal with inappropriate behaviour, the implementation of which will not be constrained by financial considerations or retention targets, and which receive the full backing of school and college managements."
The resolution instructed ATL's executive committee to look into suitable effective disciplinary measures to alleviate the "debilitating effects on children who want to learn and teachers who want to teach".
A survey released by ATL last week suggested that poor parenting could be fuelling bad behaviour in schools.
A third of teachers have dealt with physical violence recently and behaviour has worsened in the last five years, with pupils kicking, punching, pushing and shoving school staff, it said.
The current government has given teachers greater powers to search pupils, to issue no-notice inspections and clarified guidance on use of force.
Dr Bousted said she believed that these measures have been helpful to teachers.