After they downed their drinks, the subjects were given three tasks. First, they played a gambling game on a computer, in which they won money each time they inflated a balloon a little farther, but each inflation came with a chance the balloon would pop and they would lose everything. Second, they were shown photographs of 15 women and asked whether they’d approach each in a bar and whether they thought they would get her number (the subjects were all heterosexual). Finally, they filled out surveys describing how drunk they had felt during the experiment and how long they would wait before getting behind the wheel to drive, among other points.
The results showed a clear trend. The vodka-Red Bull group—who, just to remind you, drank exactly the same thing as everyone else—reported feeling much drunker and took more risks than the others, with a 12-percent increase in pumps to the balloon. They were also more confident when it came to approaching women, expressing greater certainty of getting their numbers. In fact, the vodka-Red Bull group focused strongly on the five women who were rated the most beautiful of the 15 (ranking was done by a separate group beforehand). “No one thought they were beyond their league,” Pierre Chandon, one of the study’s authors at INSEAD, says of this group. “People who had the same drink with fruit juice, they thought these same women were beyond their reach and were much less likely to go after them.”
In all these measures, the effects were stronger in men who said in the surveys that they believe mixing energy drinks and alcohol intensifies the effects, and that alcohol makes you take risks and reduces inhibitions. That suggests that the altered behavior, says Chandon, “is not because of what [the drink] contains, but because of what you believe it does to you.”
This connects to a large body of research indicating a placebo effect is at play in how we respond to alcohol. While it is sometimes difficult to set up experiments correctly—alcohol has a hard-to-mask taste, and its absence can be recognizable to subjects—people told they are drinking booze report feeling more drunk than controls consuming the same non-alcoholic beverage. People drinking beer that’s, unbeknownst to them, non-alcoholic, report feeling more charming and attractive than people knowingly consuming it. (Sober observers watching videos of their behavior, however, did not agree.) Exactly which behaviors a placebo effect may alter, and in what way, seems to depend on a number of factors, though. Some research indicates that placebo subjects can be more alert to the potential effects of alcohol and thus more careful.
In fact, the current study found that men who saw the vodka-Red Bull label would wait longer before getting behind the wheel than other subjects. And again, the effect was stronger in men who believed that mixing the two made them more potent. “We cannot say [seeing] ‘Red Bull’ increases risks across the board,” says Chandon. “It depends on the kind of risk.” Perhaps what we’re seeing here, he suggests, is that there were some men in the sample who felt that alcohol gave them a license to act wild. But a car accident is never a desirable outcome, and so they may have exerted greater control over that particular risk.