On an ordinary afternoon at Copenhagen Central Station, a performer sets up a drum in the center of a large hall. A cellist joins him. A woman approaches with her flute. They strike up a melody that seems familiar. A clarinet and bassoon and other instruments start playing. People pull out their cell phones and record video. Within minutes an entire symphony orchestra has assembled in the middle of the station, and suddenly it’s clear that this isn’t just your typical street performance; it’s the Copenhagen Philharmonic, and the tune is Ravel’s Boléro. This musical flash mob is a very different experience from watching an orchestra perform in a music hall, perhaps because of the novelty of the surroundings.

The same sort of disconnect may explain the peculiar potency of Four Loko, a fruit flavored, caffeinated, alcoholic drink that was invented by three Ohio State University students in 2005. Following a series of reported hospitalizations, in 2010 the Food and Drug Administration declared that it was illegal to add caffeine to alcoholic beverages, and the makers of Four Loko complied.

Case closed? That caffeinated alcoholic drinks are dangerous is clear, but is caffeine the culprit? Shepard Siegel, a psychologist at McMaster University in Ontario writing in a recent issue of Perspectives on Psychological Science, doesn’t think so.

For one thing, caffeine doesn’t seem to affect the way that alcohol gets absorbed by the body. Moreover, many drugs, including alcohol, are known to be more potent if they are taken in an unusual context. In a 1976 paper in Science, Siegel termed this the “situational specificity of tolerance.” Environmental variables ranging from the room where a drug is administered to flavor cues can influence an individual’s drug-related tolerance. What this comes down to is classical Pavlovian conditioning. The body of a social drinker learns to prepare for the alcohol in response to the environment, before the alcohol is even ingested. Siegel’s argument is that people became especially drunk after drinking Four Loko because of the unexpected way in which it was presented: it doesn’t actually taste like alcohol.

If Siegel is right, the decaf approach that the manufacturer of Four Loko has now taken could be troubling. It has announced a new beverage that comes with “a brand new flavor profile every four months.” This doesn’t fix the problem. Once someone becomes tolerant to the effects of the alcohol in one flavor, his or her tolerance would be eliminated when the next one is released. Intentional or not, Four Loko takes advantage of the situational specificity of tolerance. It has more in common with the
Copenhagen Philharmonic flash mob than with your morning cuppa joe.