"Our data shows that marital conflict is not a major culprit," said epidemiologist Nick Martin, from the Queensland Institute of Medical Research. "Rows have often been blamed for ratbag behaviour but we've got no evidence to suggest that they are the problem." Researchers, including several from the US, studied 1,045 pairs of twins and their children to see whether the link between parental fighting and kids' conduct problems was genetic or environmental. They found that children of an identical twin had the same levels of behavioural problems regardless of whether it was their parent or their parent's identical sibling that had marital rows.