A number of studies of AAB have found statistically significant genetic associations or gene-by-environment interactions with measures of early environmental adversity for variants in candidate genes or gene regions (for example, 5-HTTLPR, COMT and MAOA).8, 9, 10 A recent meta-analysis found evidence for associations between antisocial behavior (measured across a range of ages) and variation in the serotonin transporter gene SLC6A4 (that is, the 5-HTTLPR polymorphism) and the monoamine oxidase A (MAOA) gene.11 Although there has been longstanding controversy surrounding failures to replicate and publication bias for candidate gene approaches,12 it was only recently that researchers began to systematically examine how common genetic variation across the genome is associated with AAB. No single-nucleotide polymorphisms (SNPs) met genome-wide significance in the genome-wide association study (GWAS) by Tielbeek et al.13 of non-diagnostic categorical measures of AAB in two Australian samples. The most highly associated gene to emerge from their analysis was DYRK1A (P=8.7 × 10−5) on chromosome 21, which is a candidate gene for developmental disabilities.14 In this same study, attempts to replicate the associations between seven candidate genes or polymorphisms from
