Development of physical aggression: Exploring the relationship with language

Objective: Physical aggression begins to emerge during infancy with highest rates occurring between 2-4 years of age. By kindergarten most children learn to control their aggression. The reduction in physically aggressive behavior emerges around the same time that language begins to develop. This presentation examines rates of physical aggression between ages 2 and 6, the relationship between physical aggression with language, and explores gender differences in these relationships.

Methods: 513 low-income African American mothers were used for this presentation. Physical aggression was measured using 3 items from Child Behavior Checklist aggression subscale. Language was assessed using the Bayley Scales of Infant Development and the Peabody Picture Vocabulary Test.

Results: At age 2, 82% were engaging in physically aggressive behavior, while only 27% were at age 6. There was a significant positive correlation between age 2 and age 6 physical aggression (r = .25, p= .001), and a significant inverse relationship between language and physical aggression at age 2 (r = -.20, p= .001) and age 6 (r = -.13, p= .007). Extremely high rates of physical aggression were found among 19% of the sample at age 2 and 13% at age 6. Children in the extremely aggressive group had significantly lower language scores. The relationship between physical aggression and language differed by gender at age 6.

Conclusions: These findings highlight the need to explore the etiology and course of physical aggression prior to school age and the mechanisms through which language may affects the reduction of physically aggressive behavior.