From NYTimes story:
In a series of studies in the 1970s and ’80s, psychologists at the University of Washington put more than 300 students into a study room outfitted like a bar with mirrors, music and a stretch of polished pine. The researchers served alcoholic drinks, most often icy vodka tonics, to some of the students and nonalcoholic ones, usually icy tonic water, to others. The drinks looked and tasted the same, and the students typically drank five in an hour or two.
The studies found that people who thought they were drinking alcohol behaved exactly as aggressively, or as affectionately, or as merrily as they expected to when drunk. “No significant difference between those who got alcohol and those who didn’t,” Alan Marlatt, the senior author, said. “Their behavior was totally determined by their expectations of how they would behave.”
In a repeat of the session performed for a coming documentary, one participant insisted that she could not have been drinking because alcohol always made her flush.
“We told her that, yes, in fact she was drinking it,” Dr. Marlatt said. “She immediately flushed.”