"People may think children that young are passive and unaware, but they pay attention to what's happening around them," Megan Holmes, assistant professor of social work at the Jack, Joseph and Morton Mandel School of Applied Social Sciences at Case Western Reserve in Cleveland, said in a statement.
Holmes analyzed the behavior of 107 children exposed to intimate partner violence in their first three years but never again after age 3. The outcomes of those children were compared to 339 children never exposed to home violence.
Those studied were from the National Survey of Child and Adolescent Well-Being, which included children reported to Child Protective Services for abuse or neglect. The children's behavior was tracked over five years.
Holmes said the team saw no behavioral differences between those who did or did not witness violence between the ages of 3-5, but children exposed to violence increased their aggression when they reached school age. However, for those exposed, the more frequently intimate partner violence was witnessed, the more aggressive the child behaviors became.
Meanwhile, children never exposed to intimate partner violence gradually decreased in aggression, the study said.
Holmes reported her findings in the spring issue of Journal of Child Psychology and Psychiatry.