The aim of this piece of research was to study the existence of clusters based on anger, empathy and cortisol and testosterone measures associated with aggressive behavior in school-aged children. The sample group comprised 139 eight-year-old children (80 boys and 59 girls). Aggressive behavior was measured using the Direct and Indirect Aggression Scale. Both psychological and biological variables were used to determine psychobiological profiles. The psychological variables considered were trait anger, measured using the State-Trait Anger Expression Inventory for Children and Adolescents, and empathy, measured using the Empathy Quotient-Child Version. Testosterone and cortisol concentrations were measured through saliva samples and analyzed using an ELISA (Enzyme-linked immunosorbent assay). A Cluster Analysis revealed three clusters which were clearly different as regards their psychological and biological characteristics. The analysis of variance (ANOVA) revealed that the cluster characterized by having higher anger levels, lower empathy levels and higher testosterone and cortisol levels was more aggressive than the other two (p < .0001, η2 = .19). The results indicate that studying psychological and biological variables together may help establish differentiated aggression patterns among children.
Keywords: aggressive behavior; anger; cortisol; empathy; testosterone.