Social Exclusion, Social Acceptance, And The Effects Of Dopamine Metabolic System Genes On Attacks: An Experimental Study

Aggression has been a long standing and basic issue of psychological research. Existing studies have indicated that social exclusion and social acceptance affect the individuals' aggressive behavior. The one who is rejected usually feel mad and then show aggressive behavior. This view has accounted for aggressive behavior from a social relationship standpoint, however, ignored the differences in the nature of association between social rejection and aggression among individuals: why some individuals maintain a lower level of aggressive behavior than people sensitive to social rejection. Inspired by the principles of behavioral genetics, genotype was introduced into the study as an important influencing variable to explore the interaction of genotype and social exclusion/social acceptance on aggressive behavior.Social rejection and social acceptance experience was induced by cyberball in this study. Aggressive behavior was measured by the Hot Sauce Paradigm, the hostility was measured by the State Hostility Scale, and aggressive motive was measured by the Aggressive motives Scale. DNA samples were collected in order to assess the rs4680 and rs6323 functional polymorphism. The main conclusions were as follows:(1) There was no significant main effect of rs4680 and rs6323 for aggressive behavior, hostility and aggressive motive.(2) There was significant main effect of social exclusion and social acceptance for aggressive behavior, hostility and aggressive motive. Participants who accept social exclusion had significant rising on aggressive behavior, hostility and aggressive motive.(3) Results of MNOVA of second measure and repeated measures analysis of variance suggest the rs4680 polymorphism significantly interacted with social exclusion and social acceptance on hostility and aggressive motives. Carriers of AG/AA had higher score on hostility and aggressive motives than carriers of GG when accept social exclusion. There was no significant interaction effect between rs6323 and social exclusion, social acceptance on hostility, aggressive motives and aggressive behavior. However, there may be interaction effect between rs6323 and social exclusion/social acceptance on aggression.(4) The interaction between rs4680 and social exclusion/social acceptance on hostility and aggressive motives was better accounted for by the differential susceptibility model.