Gamblers under the influence of alcohol place higher bets after losses

When gamblers get tipsy, they tend to follow a losing spin of the roulette wheel with higher bets than sober gamblers do.

Roulette wheel with shot glasses

Gamblers don’t always make rational decisions. Their approach to any given bet is often influenced by the bets, wins and losses that have come before it—even when those things have no bearing whatsoever on the outcome.

A study recently published in Psychopharmacology by researchers from the Centre for Gambling Research at UBC and colleagues in the U.K. examined the effects of alcohol on these irrational decisions.

We spoke with professor Luke Clark, director of the Centre for Gambling Research at UBC and senior author of the study, about their findings.

What was the aim of this study?

Luke Clark

Gambling and alcohol are closely linked activities, and the disinhibiting effects of alcohol are well established. But we don’t know very much about how alcohol influences gambling decisions. In this experiment we used a roulette task where, under normal circumstances, people actually show a number of irrational biases. One example is the classic “gambler’s fallacy.” Even though each spin of the roulette wheel is independent, a run of three or four of the same colour makes someone strongly believe that the other colour is due next. We wanted to test how alcohol would affect those kinds of normal, but irrational, biases.

How did you set up the experiment?

We randomized 46 male student participants, who all had at least some prior experience with alcohol and gambling, into two groups. One group received an alcoholic drink of vodka, tonic and bitters. The other received a placebo drink of just tonic and bitters. They drank enough of these based on their body weight to reach a mildly intoxicating dose for the alcohol group. Twenty minutes later they played the roulette game on a computer. On each spin they would place a small bet on either red or black.

What decision-making biases did you observe?

As we’ve seen previously, the participants showed a number of what we call “sequential biases.” After a run of either colour, they tended to choose the other colour. The amounts they were betting were also sensitive to winning and losing streaks, with the amount increasing on long losing streaks. It surprised us that those effects were not noticeably influenced by the alcohol treatment.

What effect did the alcohol have?

The clearest effect was on betting immediately after a win or immediately after a loss. The alcohol group placed higher bets after losses compared to wins, whereas the placebo group did not show any such difference. A 1999 study in Australia saw a similar effect, but using a quite different task. This may indicate “loss chasing” under the influence of alcohol.

What is loss chasing?

Loss chasing is when a gambler either continues gambling, or in some cases even goes back another day, to try to recover their debts. Because gambling games have a house edge, what often happens with chasing is that the gambler’s debts get worse. So this can be quite a desperate behaviour, and it’s one of the hallmarks of someone losing control over their gambling.

What are the implications of these findings for gambling policy?

Our findings strengthen the case for paying careful attention to alcohol availability in gambling venues, and monitoring alcohol consumption in people who are gambling. And given the rise of online and smartphone gambling, the public also needs to be aware of the risks of alcohol use when gambling in the home.