Participants were randomly assigned to consume either a no-alcohol control beverage [n = 22 (11 women)], an active placebo beverage [n = 22 (11 women)], or an alcohol beverage [target breath alcohol concentration (BrAC) = .10%; n = 23 (11 women)]1. Participants in the control condition were informed that their beverage contained no alcohol; those in the other two conditions were told that their beverage contained “a moderate amount of alcohol.” In the alcohol and placebo conditions, an experimenter ostensibly prepared a beverage containing a moderate dose of alcohol mixed in a 5:1, tonic to vodka ratio. The placebo dose was achieved with diluted vodka (9 parts flattened tonic to 1 part 100-proof vodka, poured from a Smirnoff Blue Label bottle) and tonic; the alcohol dose was achieved using 100-proof vodka and tonic, calculated based on total body water volume (estimated using age, gender, height, and weight) and the duration of the drinking period (15 min), using published formulas (see Curtin & Fairchild, 2003; Watson, 1989). Total beverage was isovolemic across conditions. In each condition, the beverage was divided into
