"We found that the quality of a parent's emotional interaction and attachment with a young child is crucial to predicting if that child will develop this high-risk pattern of behaviour," said Dr David Hawes, the research leader from the School of Psychology at the University.
"Based on our findings we can now test early-intervention strategies to help these parents and their children."
Children who from an early age show a fearless temperament and do not show interest in other people's emotions, especially when they are upset or in need of help, are known to researchers as having "callous-unemotional" (CU) traits. These children typically also lack guilt or concern about behaviours that would produce guilt in most children.
"While most children with conduct problems do not show CU traits, those who do are at greater risk for ongoing problems - particularly aggression. These children are indifferent to punishment for poor behaviour and in fact the more severe the punishment the worse the behaviour becomes," said Dr Hawes.
Callous-unemotional behaviour has been shown to be a strong indicator of psychopathic behaviour and violent crime in adulthood.
Dr Hawes and his colleagues have just completed a four-year study, funded through the Australian Research Centre, looking at children aged two to four with CU traits.
The research was unusual in concentrating on very young children and being based primarily on direct observation. It used video analysis to evaluate the quality of interactions and attachment between mothers and children.
"The study suggests that the emotional bonds between mothers and their children strongly predict if they will show high levels of CU traits, as well as conduct problems," said Dr Hawes.
Until recently the quality of a child's parenting was not believed to have an impact on either callous-unemotional or the behaviour of children with such traits, but this research suggests that strengthening the emotional bonds between parents and their infants can make a difference.
"While CU characteristics seem to be largely under the control of genetics if a child receives consistent and warm parenting in a secure family environment it can protect against those traits. This aspect of parenting is still relevant in terms of influencing the traits even though it is not the cause.
"In fact its protective effects - its ability to prevent the development of aggressive and oppositional behaviour - also appear to be strongest for children with the highest level of CU traits."
The main implication of the study is that CU children benefit less from current parenting interventions for conduct problems because they are focused on reducing negative parenting instead of on the quality of the parenting relationship.
"While research with older children and adolescents has previously shown that CU traits are associated with more severe behaviour problems regardless of harsh and inconsistent discipline, our research suggests that this may not be the case in early childhood. Most importantly however, we found that it was only among the CU children that having an emotionally warm relationship protected against conduct problems."
The researchers now plan to evaluate programs specifically aimed at improving quality of attachment by employing strategies shown by the current study to be highly beneficial.
They include emphasising eye contact during emotional interactions, giving the child language to express emotion and the skills to identify emotion in other people.
"Parents with very difficult-to-handle children might be told it is a phase - the terrible twos - but that does not apply for children at risk of antisocial behaviour. For them the earlier we can address the issue the better.
"For our research we were in the privileged position of being able to work with Karitane, one of the only community health services in the world which specialises in clinically significant behaviour problems in very young children."
Dr Hawes presented his research at the International Association for Child and Adolescent Psychiatry and Allied Professionals conference on 20 July.