Age differences in aggression in Bulgarian primary school age children

In order to study the age differences of the status of aggression from the beginning to the end of the primary school age, 244 typically developing Bulgarian children were examined with the adapted for Bulgarian population questionnaire for measurement of aggression and depression in primary school age children. The total sample was divided into 2 age groups: first graders’ group (6-8 years, Mean age = 6.99, SD = 0.189; N = 82; 42 girls) and fourth graders’ group (9-11 years; Mean age = 10.23, SD = 0.450; N = 162; 79 girls). It was suggested that age-related differences in aggression status were present in the age range considered. It was also assumed that there were some gender differences in the participants’ aggressive status. The results did not reveal any statistically significant differences between the two age groups in the mean aggression scores, suggesting no essential aggression change in this age period. As regards to the effect of the participant’s gender, some statistically significant differences between the age subgroups in the mean aggression scores were found, with the boys demonstrated higher aggression than girls, suggesting that the subjects’ sex was a factor with significant effect on the level of aggression in this age period.