Using the results from these analyses, polygenic scores (PGS) were calculated in samples not included in the GWAS, including from the Collaborative Study on the Genetics of Alcoholism (COGA) where it was found to explain 8.9% of the variance in a latent phenotypic factor among EA adults (Karlsson Linnér et al., 2021). The externalizing PGS (EXT PGS) was significantly associated with relevant externalizing phenotypes such as disinhibited behavior (e.g. rule breaking, aggression), externalizing disorders (e.g. ADHD, CD, alcohol use disorder), and related social outcomes including criminal justice involvement (e.g. arrest, felony conviction), and socioeconomic outcomes (e.g. lower levels of college completion, lower household income; Karlsson Linnér et al., 2021). While recent publications have continued to validate the EXT PGS, finding significant associations between the EXT PGS and externalizing outcomes among EA, but not African ancestry (AA) adolescents (Kuo et al., 2021), it is still unknown how the EXT PGS is associated with established neurophysiological indicators of externalizing.
