This inclusive item selection approach led us to map our three aggression phenotypes onto items from three different sections of the SSAGA. Alcohol-related aggression items were taken from the ‘Alcohol’ section of the SSAGA, in which participants reported whether they had ever in their lives perpetrated four different acts of aggression and we coded their responses as ‘0 = No’ or ‘1 = Yes’. Drug-related aggression items were taken from the ‘Drugs’ section of the SSAGA, in which participants reported whether they had ever in their lives experienced a physical fight because of one of five types of drugs and we coded their responses as ‘0 = No’ or ‘1 = Yes’.
