Based on a small sample size, more than 70 percent of adults convicted of abusing their own kids — or children they lived with — experienced being abused or neglected when they were children themselves, a survey showed Saturday.

Even though the survey by Japanese research institute Riken is based on a small sample of 25 people, Kumi Kuroda, a psychiatrist who led the survey, said its results show that effects of abuse and neglect could extend into adulthood and that people with adverse childhood experiences need outside support in their parenting.

Kuroda's survey team contacted 124 people who were serving time in prison for child abuse and sent a set of over 400 questions to those who offered to cooperate.

Of 25 people who responded, 18, or 72 percent, said they had adverse childhood experiences such as physical abuse, neglect or emotional maltreatment, the survey found.

Eleven of them, or 44 percent, had mental health problems such as depression and alcoholism, and 17, or 68 percent, were in challenging parenting situations such as having three or more infants to raise or having children with health problems.

The team also surveyed 74 adults who have no record of abusing children, and 13 of them, or 18 percent, said they experienced abuse or neglect as children.