Researchers Identify Cognitive Process That Contributes To Gambling Behavior

June 02, 1997

WASHINGTON -- Gambling has always been a big business and as more states adopt lotteries and permit casino gambling it gets even bigger every year. From 1993 to 1994, the number of casino visits in the United States rose 35 percent to 125 million and those casino visitors left behind $16.5 billion in losses, more than twice as much as they lost in 1990. But if gambling is, overall, a losing proposition for the gambler, why do so many people do it?

Over the years, psychological researchers have identified several thinking processes that contribute to gambling behavior. These include biased evaluations of past gambling results (explaining away losses and viewing wins as evidence of gambling ability), the illusion of control (overestimating the influence one wields over outcomes and the probability of personal success) and the "gambler's fallacy" (the mistaken belief that over time, chance-determined outcomes will even out).

In the June issue of the American Psychological Association's (APA) journal Experimental Psychology: Applied, researchers from Central Michigan University and the University of Utah add another cognitive process to that list: selective hypothesis testing, that is, considering only one possible outcome when making decisions.

The researchers conducted a series of three experiments, in the first of which participants were asked to estimate the probability that a specific National Basketball Association team (one of four) would win the NBA championship and explain how. In the second experiment they were also asked to estimate the probability that a specific NBA team beat the point spread in an earlier game. In the third they were asked to estimate the probability that an NCAA basketball team (one of four) had won a computer-simulated playoff. In each experiment, participants were invited to place bets on the team they thought would win, had beaten the point spread or had won.

In each experiment participants who focused (as instructed) on a single team (as opposed to estimating the probability of winning for all four teams they were considering) consistently overestimated the probability of that team winning. In addition, study participants who overestimated that probability were more likely to place bets and larger bets than those who were not focused on a single team.

This overestimation of probability, the authors say, "could influence gambling decisions in any domain in which the potential gambler may focus on one possible outcome to the exclusion of others. Thus the blackjack player may be particularly interested in the likelihood of receiving a 10 after her or his first two cards sum to 11, the poker player may be particularly interested in the probability of making a straight on her or his next card, and the sports gambler may be particularly interested in the likelihood that the home team may win the league championship."

But, the authors note, selective hypothesis testing is avoidable. In one of the experiments, some participants (the control group) had to estimate the probability of each of four teams winning a computer-simulated championship. Under that condition, the participants overestimated the probability of winning for all four teams, indicating that they may have considered each team a viable contender. But these participants were less likely to gamble than those who had focused on only one team. "By encouraging potential gamblers to consider a wide number of potential outcomes, the appeal of any specific outcome is lessened and the likelihood that a bet will be placed is reduced," the authors write. "Thus, this specific cognitive strategy may counteract the influence of the selective hypothesis-testing process."

Not only might this strategy be useful in the treatment of problem gamblers, the authors suggest it might be useful in preventing gambling problems from developing. Training in abstract reasoning skills in secondary schools or college courses "could include a specific component that addresses the necessity of considering numerous potential outcomes when attempting to predict future events. This research suggests that such training could be relatively general in nature and still be readily applied by students to gambling and other risky choice situations."

Article: "The Effects of Selective Hypothesis Testing on Gambling," by Bryan Gibson, Ph.D., Central Michigan University, and David M. Sanbonmatsu, Ph.D., and Steven S. Posavac, Ph.D., University of Utah, in the Journal of Experimental Psychology: Applied, Vol. 3 No. 2.

(Full text available from the APA Public Affairs Office.)

Bryan Gibson, Ph.D. can be reached at (517) 774-4404 or at

The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 151,000 researchers, educators, clinicians, consultants and students. Through its divisions in 50 subfields of psychology and affiliations with 58 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting human welfare.

# # #

American Psychological Association

Related Gambling Articles from Brightsurf:

Gambling addiction: an aid from patients' stories
How do people affected by pathological gambling tell their story?

Links between video games and gambling run deeper than previously thought, study reveals
A new study suggests that a number of practices in video games, such as token wagering, real-money gaming, and social casino spending, are significantly linked to problem gambling.

Leading academics call for statutory levy on gambling firms to reduce harm
Leading UK academic scientists are urging the government to introduce a statutory levy on gambling firms to deliver reductions in gambling harms.

How sound and visual effects on slot machines increase the allure of gambling
The sights and sounds of winning on a slot machine may increase your desire to play--and your memories of winning big, according to new research by University of Alberta scientists.

Near misses on slot machines may not encourage continued gambling
For nearly 70 years, researchers believed that near-miss events like these would encourage you to continue gambling.

UMass Amherst researchers release new findings in groundbreaking gambling study
New findings released Sept. 12 from a groundbreaking gambling study by a University of Massachusetts Amherst research team show that out-of-state casino gambling among Massachusetts residents decreased significantly after the Commonwealth's first slot parlor, Plainridge Park Casino, opened in Plainville in the summer of 2015.

Lure of the 'loot box' looks a lot like gambling
An increasingly popular feature of modern video games is attracting gamers who share the beliefs and behaviours of problem gamblers, new UBC research has found.

Gaming or gambling? Online transactions blur boundaries
In-game purchasing systems, such as 'loot boxes', in popular online games resemble gambling and may pose financial risks for vulnerable players, according to gambling psychology researchers at the University of Adelaide.

UMass Amherst team reports gambling research results to Massachusetts Gaming Commission
Results of a baseline study on gambling behavior in Massachusetts that establishes how people participated -- or not -- in gambling prior to the opening of any casinos were reported on Jan.

When new players learn slot-machine tricks, they avoid gambling addiction
Novice gamblers who watched a short video about how slot machines disguise losses as wins have a better chance of avoiding gambling problems, according to new research.

Read More: Gambling News and Gambling Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to