Antisocialno vedenje (AV) je vedenje, ki je v nasprotju s prevladujočimi pravili in normami in se kaže kot fizično in psihično nasilje, povzročanje materialne škode, kraja, vandalizem, spolna promiskuiteta, alkoholizem, uživanje prepovedanih substanc, odvisnost od iger na srečo, laganje, manipulacija in prevare. AV je pogosto povezano z drugimi oblikami vedenjskih in razvojnih motenj, kot so hiperaktivnost, depresija, motnje učenja in impulzivnost. Ker predstavljajo AV in z njim povezane posledice resen družbeni problem, so raziskave vzrokov in dejavnikov tveganja za AV zelo pomembne. Politični, socialni in ekonomski dejavniki tveganja za AV so dobro raziskani, narašča pa tudi zanimanje za biološke dejavnike. Meta-analize študij AV pri dvojčkih in posvojencih so pokazale, da z genetsko komponento lahko razložimo tudi do 50% fenotipske variance AV. Fenotip AV je heterogen in se pojavlja hkrati z drugimi vedenjskimi motnjami. Molekularno-genetske študije AV na ravni celotnega genoma kažejo, da gre za kompleksen fenotip, ki ga oblikuje več lokusov. V študijah kandidatnih genov so identificirali povezave med AV in genetskimi polimorfizmi dopaminergičnih genov (DAT1, DRD2, DRD4), serotonergičnih genov (5-HTTLPR) in genov za encime, ki razgrajujejo monoamine (COMT, MAOA). V študijah AV se kot možna strategija izkaže uporaba živalskega modela (miši), saj omogoča zasnovo študije z definiranim genotipom in s kontroliranim okoljem. Pri prašiču so polimorfizme gena MAOA povezali z agresijo, pri različnih skupinah pasem psov pa so v zaporedju MAOA identificirali razlike v frekvencah alelov. Antisocial behaviour is a type of behaviour that is contrary to predominant rules and norms and is exhibited as physical and psychological violence, causation of material damage, theft, vandalism, sexual promiscuity, alcoholism, substance abuse, gambling addiction, lying, manipulation and fraud. Antisocial behaviour is often linked to other forms of behavioural and developmental defects, as are hyperactivity, depression, learning disabilities, and impulsivity. Because antisocial behaviour and the defects linked to it represent a serious social problem, it’s important to research the causes and risk factors for it. Political, social and economic risk factors for antisocial behaviour are well known so there is an increasing attention directed to biological factors. Meta-analysis of antisocial behavioural twin and adoption studies have shown that the genetic component is responsible for 50 % of the phenotypic variance. Phenotype of antisocial behaviour is heterogeneous and appears alongside other behavioural defects. Genome-wide molecular-genetic studies of antisocial behaviour show that antisocial behaviour is a complex phenotype with multiple loci affecting it.. Multiple polymorphic candidate genes have been identified to have a link with antisocial behaviour, such as: dopaminergic genes (DAT1, DRD2, DRD4) serotoninergic genes (5-HTTLPR) and genes that encode monoamine decomposition enzymes (COMT, MAOA). In antisocial behaviour studies animal models can be used, they allow us to design a study with a defined genotype in controlled environment (mouse). In pigs MAOA polymorphism was linked to aggression, in various groups of dog breeds differences in allele frequency in MAOA sequence among different breeds were identified.