Generations of bickering parents who have slavishly followed the old adage "not in front of the children" may be doing more harm than good, according to recent findings from the South Wales Family Study.
The Cardiff university-based research group has found that children's experiences at home can have a significant impact on their behaviour and academic performance at school.
And the more parents try to hide their arguments, the worse the consequences seem to be.
Researchers found parental conflict at home was contributing to lower-than-expected performance by some Year 9 pupils in key stage 3 tests in English, maths and science, as well as behavioural problems in school.
"If a child is stressed at home that would affect how he or she interacts with teachers and fellow pupils," said the study's director Dr Gordon Harold, of the university's school of psychology.
"Depression, anxiety, aggression and general anti-social behaviour were what we looked for during our discussions with teachers about pupils'
But those children who felt most responsible for parents' fights showed a greater deficit in academic performance than those who felt less blameworthy.
"When I first saw that this was the factor most likely to affect KS3 performance I had to check it," said Dr Harold. "We found that children who blamed themselves for difficulties in their parents' relationship had the most problems. To capture that over a long-term study period is quite special.
"Parents have traditionally gone into another room to air their differences away from the children under the misapprehension that they are not aware that mum and dad are arguing.
"If, as an adult, you are aware of an exchange which relates to you it is only natural that you want to know everything about it. Children are the same but are far more likely to jump to conclusions."
Dr Harold suggests parents should explain the nature of their disagreements to children and be seen to reconcile those differences.
"I'm not saying that parents should argue in front of their children, but you can guarantee that kids know when their parents are quarrelling," he said. "It's important they are given an explanation and see the quarrel resolved."
The five-year study, involving 543 families in mid and south Wales, is continuing and is now looking at GCSE and A-level results. The aim of the project is to assess the long-term impact of inter-parental conflict and parent-child relationships on children's emotional, behavioural and academic development from Y7-11, and to develop a parent education programme aimed at alleviating the negative effects of inter-parental conflict on children.
Dr Harold added that by 2010 step-parent families would be predominant in Britain, a major social change with dramatic implications for children.
"Conflicts between adults is a normal part of family life," Dr Harold said.
"It is how they quarrel and whether they are seen to make up which matters.
"It is important to emphasise that most children do very well - only a minority have problems."