Lorber MF, et al. - In children before 2 years of age, researchers studied age-related trends in physically aggressive behaviors. A US standard sample of 477 mothers of children aged 6 to 24 months reported the frequency of 9 interpersonally focused aggressive child behaviors, and hurting animals, in the past month. Initially, the prevalence of hitting and throwing increased, plated at 18- 20 months of age, and then decreased. Hitting and throwing frequencies increased and hair pulling and scratching frequencies decreased with age. In the 6- to 24-month age range, physically aggressive behavior seems almost ubiquitous. Forms of physical aggression are mostly, but not all, increasing with age. These outcomes can guide child specialists in teaching and counseling parents about the behavior of their child in the first two years of life.