The level of aggression between partners around the time their child is born affects how a mother will parent three years later, U.S. researchers said. Philip A. Fisher of the University of Oregon and the Oregon Social Learning Center said the study involves more than 400 mothers in high-risk family environments, based mostly on risk for child-welfare involvement and socioeconomic status in San Diego. Doctoral student Alice M. Graham, in collaboration with Fisher and Hyoun K. Kim, also a scientist at the Oregon Social Learning Center, revisited questionnaire data from 461 of the 488 initially recruited mothers who had provided information about their partner relationship during the four-year study period from birth through the child\'s third birthday from 1996 to 1997. \"Even when we accounted for other important risk factors, such as maternal depression or history of abuse, we found that the level of partner aggression at the birth of a child and change over time predicts moms\' harsh parenting at 3 years of age,\" Graham said in a statement. The study, published in the Journal of Family Psychology, found the moms\' harsh parenting in turn predicted higher levels of behavior problems for the children at age 3.