Objective: Using quantitative genetic analysis of twin study design to explore the impact of genetic and environmental factors on the prosocial behaviors of children.
Methods: One hundred and forty-seven twin pairs from Chengdu area aged 6-16 were studied using parental information of Strengths and Difficulties Questionnaire (SDQ). SPSS13.0 and Mx software were used to analyze data, including nonparametric test, Pearson correlation, genetic analyses, etc.
Results: (1) Female children score higher than males on their prosocial behavior (Ps< 0.05), except less than 11 age group; (2) Shared environmental factors were the most important for children's prosocial behaviors(C=0.48,95%CI:0.09-0.73),then the genetic factors (A=0.27,95%CI:0-0.66) and the unshared environmental factors(E=0.25,95%CI:0.18-0.35); (3)Female and those who scored higher on their fact/ideal family adaptability and cohesion scored higher in their prosocial behaviors (r:0.17-0.29). On the contrary, those who had extreme conditions during pregnancy/ perinatal period or whose caretaker had discordant opinions on parenting scored lower (r: -0.16 to 0.28).
Conclusion: Children's prosocial behaviors were influenced by genetic and environmental factors including family function and parenting environment, and genetic impact differs in different age and sex.