The influence of setting on consumption in the balanced placebo design.

Previous research using the balanced placebo design has demonstrated that instructions about alcohol content of a beverage affect consumption more than actual alcohol content. In the present experiment the balanced placebo design was expanded to include a dimension of context. The design was a 2 x 2 x 2 factorial with expectancy about alcohol content, actual alcohol content, and setting in which the experiment was conducted as factors. The setting factor involved conducting the experiment either in a laboratory setting typical of most balanced placebo research or in an actual bar-room. Results obtained in the laboratory setting replicated the basic finding that subjects consumed more beverage when they believed it contained alcohol than when they believed it did not contain alcohol, regardless of actual alcohol content. Consumption in the bar-room setting was higher than in the laboratory setting, and most importantly, consumption was not differentially affected by instruction about alcohol content or actual alcohol content. These results demonstrate the important role of setting on beverage consumption, and suggest the need to investigate factors thought to affect consumption in natural drinking environments.

RCT Entities:   Population Interventions Outcomes