title: MAOA-uVNTR genotype predicts interindividual differences in experimental aggressiveness as a function of the degree of provocation.
abstract: The MAOA-uVNTR has been suggested to play a role regarding aggression, however, results are inconsistent. We aimed at further elucidating potential effects of the MAOA-uVNTR on aggressiveness with respect to potential modulators: sex, experimental vs. trait aggressiveness and type of aggressiveness (proactive vs. reactive aggressiveness). We tested 239 healthy young adults (88 men/151 women). Participants were genotyped for the MAOA-uVNTR and performed a modified version of a competitive reaction time task - a commonly used and well established tool to elicit and measure aggressiveness. Furthermore, they completed a self-report scale measuring trait aggressiveness. We found a main effect of MAOA-uVNTR on a measure of reactive aggressiveness for both men and women, whereby the low-activity alleles of the MAOA-uVNTR were associated with substantially increased aggressive reactions (p<.05). This effect was unique for reactive aggressiveness. Measures of proactive aggressiveness or self reports were not associated with the MAOA-uVNTR-genotype. Our data are in line with earlier studies and indicate the MAOA-uVNTR-genotype to be specifically associated with measures of reactive impulsive experimental aggressiveness in healthy men and women. Furthermore the association between the MAOA-uVNTR genotype and aggressive responses increases in a fashion linear to the degree of provocation. This indicates that the low-functional alleles of the MAOA-uVNTR are not associated with increased aggressive behavior per se, but rather with an increased aggressive reactivity to provocation.
authors.affiliation: Personality Psychology and Individual Differences, Department of Psychology, Justus-Liebig-University Giessen, Otto-Behaghel-Str. 10F, D-35394 Giessen, Germany. yvonne.kuepper@psychol.uni-giessen.de
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Kuepper
authors.forename: Phillip
authors.initials: P
authors.lastname: Grant
authors.forename: Catrin
authors.initials: C
authors.lastname: Wielpuetz
authors.forename: Juergen
authors.initials: J
authors.lastname: Hennig
mesh_terms: D000328:Adult; D000374:Aggression / Q000502:physiology* / Q000523:psychology; D000483:Alleles; D003163:Competitive Behavior / Q000502:physiology*; D005260:Female; D005838:Genotype; D006801:Humans; D007175:Impulsive Behavior / Q000235:genetics*; D008297:Male; D018598:Minisatellite Repeats; D008995:Monoamine Oxidase / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011594:Psychometrics; D011930:Reaction Time / Q000235:genetics*; D057566:Self Report
chemical_list: D008995:Monoamine Oxidase