Genetic and environmental determinants in the formation of differences in aggression in same-sex siblings

Abstract

Background. The analysis of the contribution of genotype and nonshared environment caused by birth order in formation of differences in physical, indirect, verbal aggression and irritability in same-sex siblings was carried out. Materials and methods. Data of sibling from sibship size two and there parents in the Kharkov population (Ukraine) were analyzed. The aggression was defined by Buss-Durkee Hostility Inventory scales. Results of the research have been processed with statistical software packages SPSS 13.0 for Windows, MATLAB. Results. The heritability for physical aggression: h2 = 24 %, Н2 = 84 % at male siblings; h2 = 35 % at female siblings. The heritability for indirect aggression and irritability: h2 = 41 % and h2 = 36 % at female siblings. Variability of a level of indirect, verbal aggression and irritability in male siblings is depends from birth order: the increase phenotype similarity between fathers and younger sons in comparison with fathers and older sons was marked. Conclusion. Results are the basis for a conclusion about gender-specificity of gene interactions and genotype-environment interaction in formation differences of aggression. The next step of investigation is model fitting analysis.

Keywords

aggression / same-sex sibling / heritability / birth order effect

RIGHTS & PERMISSIONS

Shustikova M.V.