“I don’t know what’s wrong with me!” Having cast your merlot across your boss’s sweater, you futilely thrust a napkin in her direction. You’re no stranger to a drink. Why now—at the company picnic—has that second glass gone to your head?
Most of us know, for better or for worse, that drinking on an empty stomach, or while on prescription medications, can leave us unduly inebriated. Less familiar is a series of external cues that may determine how much we’re affected by alcohol and other substances. Shepard Siegel, a professor emeritus of psychology, neuroscience, and behavior at McMaster University in Ontario, coined the term situational specificity of tolerance in 1976. The idea is that the context in which we have a beer (or a cocktail, or methadone) helps determine the effects we feel—probably because our bodies prepare for the physiological reaction produced by a familiar drug when we think that reaction is imminent. Siegel describes the process as an example of classical conditioning (like the Ivan Pavlov experiment in which a bell was rung each time a dog was fed, with the result being that the dog salivated whenever he heard the bell) .
Take the panic a few years back over Four Loko, the “blackout in a can,” whose combination of malt liquor and caffeine was widely blamed for a spate of hospitalizations. At the time, Siegel argued that the real danger Four Loko posed to drinkers was not that it mixed alcohol and caffeine, but that it provided alcohol outside its usual context—with candy-like flavors, in tall, brightly colored cans that made it look like soda. A 1997 study by other researchers bears out the point: Subjects were all given the same amount of alcohol, but some of them consumed that alcohol in the form of beer, while others were plied with an unfamiliar “blue peppermint mixture.” The latter group—the group that didn’t know what was coming—did significantly worse on cognitive and motor tests .