Participants were asked whether or not they had ever had a drink of alcohol excluding small tastes and sips. Those who answered yes were asked further alcohol questions, such as how they would describe their current use (self-attribution of use: “abstainer,” “abstainer – former problem drinker in recovery,” “infrequent drinker,” “light drinker,” “moderate drinker,” “heavy drinker,” and “problem drinker”). Participants were asked on how many days they had one or more drinks in the past 30 days and how many drinks they usually had on days that they drank. Both questions were free response. A frequency/quantity variable was then created by multiplying a participant's score on frequency by their score on quantity. Participants were asked at what age they began to drink regularly, defined as drinking at least once a month for 6 months or more. They were also asked how old they were when they first got drunk, defined as having slurred speech or being unsteady on one's feet. Questions related to symptoms of alcohol dependence were included, as adapted from the Semi-Structured Assessment of the Genetics of Alcoholism
