We obtained data from the Collaborative Study on the Genetics of Alcoholism (COGA), a multi-site study of probands who were in treatment for alcohol use disorder and their family members, as well as a smaller number of comparison families (see Nurnberger et al., 2004 for more detail). Data collection for COGA proceeded across multiple phases. From the first phase of the COGA dataset, we identified 9,325 participants who provided aggression data. Our preregistration plan stated that we would only include data from this first phase of the COGA project but we deviated from this plan and decided to include participants from later phases in order to reduce type I and II error rates via greater statistical power. This resulted in a final sample of 13,490 participants1 (see Table 1 for sample demographics).
