Parents are most likely to blame their child's friends for naughty behaviour in the classroom, a survey suggests.
Bullying and boredom are also top causes of disruptive behaviour, according to the Netmums poll.
It also revealed that parents think children are naughtier now than when they were young.
More than nine in 10 (92.8 per cent) parents think a child's friends can influence bad behaviour at school - making it the most popular answer.
More than four-fifths (83.9 per cent) said bullying affects behaviour, while 78.2 per cent cited boredom.
The poll asked almost 900 parents for their views on behaviour in schools.
The findings show that two-thirds (65.6 per cent) of parents think that children are more badly behaved at school now than when they were in the classroom.
And half (51.1 per cent) said that schools dealt with discipline better when they were at school than they do now.
Many parents also believe that talking is a better solution to bad behaviour than suspending or expelling youngsters.
Some 83 per cent of those questioned said that talking through right and wrong behaviour is the best method for disciplining children at school, making it the top answer.
Nearly three-quarters (73.6 per cent) were in favour of detentions, while 39.5 per cent backed suspension and 29.6 per cent backed expulsion.
Just 9.8 per cent were in favour of corporal punishment.
Parents were also asked for their views on the Government's plans to tackle unruly behaviour in school.
Some 85.6 per cent backed plans to give teachers more powers to deal with bad behaviour, such as being able to search pupils for banned items.
More than two-thirds (68.2 per cent) said teachers should be able to conduct searches on school premises without consent, although more than a fifth (22.1 per cent) said they did not believe such methods would address the causes of bad behaviour.
Siobhan Freegard, co-founder of Netmums, said: "There are many factors that can influence a child's behaviour and it is essential that teachers and parents together are able to look behind the behaviour at the causes - and respond to that with a consistent combination of support and discipline.
"If the Government is to give teachers new rules and regulations when it comes to disciplining our children in school, it is important that we as parents understand these fully and are comfortable with them and trust our teachers to stay within the guidelines."
:: The poll questioned 872 parents through the Netmums website in December.