Children exposed to violence, substance abuse and mental illness are more likely to experience violence from their partner later in life, new Kiwi research has found.
But little is being done to prevent it, the researchers behind the study say.
Nearly 3000 people were interviewed on adversities they faced in childhood, and whether they had experienced domestic violence as an adult.
"Had they seen their mother being beaten while they were a child?" said study author Janet Fanslow, associate professor at the University of Auckland's School of Population Health. "Did members of the household have problems with substance abuse or mental illness? Were there incarcerated household members?"
They were also asked whether adults swore at or insulted them, or if they were subjected to other forms of abuse, such as emotional or sexual.
Dr Fanslow said there "anyone who had had even one adverse childhood experience" was twice as likely to experience violence from a partner than people who hadn't.
"By the time people had four or more of those forms of adversity in childhood, the risk increased exponentially - almost six or seven times more likely, compared to people who hadn't had those adverse experiences."
People exposed to adverse childhood experiences are more likely to end up "imitating or tolerating those behaviours".
The prevalence of childhood adversity was surprising, she said.
"Over half of the population that we surveyed reported having at least one adverse childhood experience, and almost one out of nine reported having four or more of these adversities. It is really common. It's not just a small problem."
For Māori, the figures were worse - almost eight out of 10 Māori adults having experienced at least one adverse childhood experience.
Māori, unemployed, people living in deprived areas and lacking food security were also more likely to report having difficult childhoods.
"We know that children who are in chaotic life circumstances, it does really affect their brain development so they get levels of disrupted neurodevelopment," said Dr Fanslow.
"That feeds into both social problems, emotional problems and even thinking problems as they get older. That in turn is a contributing factor to a whole range of different adverse experiences - health problems, but also social problems like violence."
She said there needs to be more focus on setting up "evidence-informed and culturally-informed intervention services for when this adversity is occurring".
"We also need to work on more holistic assessments of what might be going on. Often we have systems that are designed to see one piece of the puzzle, rather than the collection of things that are going on."
The research was published in the latest issue of journal Child Abuse & Neglect.