Behavior Research Methods, Instruments, & Computers 2004, 36 (1), 96–100 A computerized simulation for investigating gambling behavior during roulette play OTTO H. MACLIN University of Northern Iowa, Cedar Falls, Iowa and MARK R. DIXON Southern Illinois University, Carbondale, Illinois The present paper describes a computerized roulette program for the conducting of psychological research on gambling behavior. The program was designed to simulate an actual roulette game found in casinos and gambling riverboats throughout North America. The roulette program collects detailed trial-by-trial data on player/participant behavior that can easily be transferred into data analysis and graphics programs. This multimedia simulation was designed in the Visual Basic programming lan- guage, and it is capable of running on any IBM-compatible personal computer running the Windows 2000 or higher operating system. The opportunityto engagein legalizedgamblingin North jectiveprobabilities(Kahneman & Tversky,1972).Another America has drastically risen over the course of the past approach that has been growing in acceptance is that the two decades. Only 2 of the 50 states permitted some form pure chance consequences of the gamble itself tend to of legalized gambling (Nevada and New Jersey) 20 years strengthen future gambling behavior (Dixon, Hayes, Reh- ago. Today 48 states allow a type of gambling while only feldt, & Ebbs, 1998; Ladouceur, Gaboury, Domont, & Ro- two (Utah and Hawaii) prohibitit (Ghezzi, Lyons,& Dixon, chette, 1988). 2000). The increase in gambling opportunitieshas come at One way to better understand the potential controlling a considerable social cost. For example, it has been re- variablesof variouscasinogamesis to study them via a com- ported that the percentage of our national populationwho puterized simulation. Such simulations allow researchers have problem gambling behavior has risen from an esti- to conduct experimental analyses far more extensively mate of 1% in 1974 (Ladouceur,Boisvert,Pepin, Loranger, then they can in a casino where heavy regulations govern & Sylvain, 1994) to approximately 3% today (American the observation and recording of player data. Furthermore, Psychiatric Association, 1994). In addition, people with simulations allow the researcher to control and manipu- gambling problems have been shown to commit more late variables in ways that would never be possible in such income-related crimes than do people from nongambling naturalistic settings. Such variables include the minimum comparison groups (Blaszczynski & McConaghy, 1994). or maximum bet wagered per person, the size or probabil- The increase of pathologicalgamblers suggests that either ity of a given payoff, or the level of risk (or perceived risk) this personality type is on the rise, or that the availability that a player takes on a given wager. of gamblingitself can produce financial hardship and prob- To date there have been two computerized simulations lem behaviors in a previous nongambler. of the most popularmachinetype gamesfound in the casino, Previous psychological research has shown that there video poker and the slot machine. The video poker simu- are a variety of reasons why people may engagein gambling lation published by Dixon, MacLin, and Hayes (1999) al- when the stakes of winning are against them. It has been lowed researchers to manipulate jackpot sizes, the maxi- claimed that certain individualsare attracted to sensation- mum number of coins wagered per hand, and the total seeking opportunities, and that gambling is one such ac- number of hands played. It also allowed for a subjective tivity (Anderson & Brown, 1984).Others have argued that probabilityquestion asking the participant to estimate the certain people generally lack an objective view of actual chances of winning on the next hand to be either present probabilities, and take irrational risks or make poor deci- or absent following specific trials. The poker program per- sions on the basis of their possession of inaccurate sub- mitted the collection of a number of time-based dependent measures, includingengagementtime and response latency, along with response-based dependentmeasures, including the number of coins wagered, won, or lost on each hand. Correspondenceconcerning this article shouldbe addressed to Mark R. Dixon, Behavior Analysis and Therapy Program, Rehabilitation Insti- Published data obtained from this simulation have re- tute,SouthernIllinoisUniversity,Carbondale,IL 62901(e-mail: mdixon@ vealed temporal regularities in poker players whereby the siu.edu). rate of play accelerates following losing trials and decel- Copyright 2004 Psychonomic Society, Inc. 96 ROULETTE SIMULATION 97 erates following winning trials (Dixon & Schreiber, 2002). matches a bet that the player has made, the player wins Many players also tended to underestimatetheir frequency double the chip(s) bet. For example, if a player bets 2 chips of winning trials and underestimatetheir frequency of los- on the space “red,” and if the number that comes up is red, ing trials when given a postsession estimation question- the player receives a total of 4 chips in return. naire of wins (Dixon & Schreiber, 2002). A 2:1 bet is made by the player by placing a chip(s) in The slot machine simulation published by MacLin, the next row up on the board (1st 12, 2nd 12, 3rd 12) or the Dixon, and Hayes (1999) allowed researchers to manipu- right column of the board (2:1s). If the number on which late probabilities of payoffs, visual display of potentially the ball lands matches the bet the player has made, the winning symbols, size of the maximum bet per spin, and player wins three times the chips bet. For example, if the the jackpot sizes of winning combinations. The slot ma- player bets 2 chips on the space “1st 12,” and if the num- chine program also allowed for the collectionof a number ber that comes up is between or includes 1 and 12, the of time-based and participant response-based measures, player receives a total of 6 chips in return. including response latency and subjective probability es- An 8:1 bet is made by the player by placing a chip(s) in timations. Published data obtained from this simulation the intersectionsof every four numbers located in the mid- have also revealed temporal regularities in slot machine dle of the board (e.g., the intersection of 8, 9, 11, and 12). players whereby the rate of play acceleratesfollowinglosing If the number on the wheel on which the ball lands matches trials and decelerates following winning trials (Schreiber the bet the player has made, the player wins eight times the & Dixon, 2001). Both simulations were programmed in chip(s) bet. For example, if a player bets 2 chips on the the Visual Basic programming language and were de- space between “8, 9, 11, & 12,” and if the number that signed to run on any IBM-compatiblecomputerequipped comes up is 8, 9, 11, or 12, the player receives a total of 16 with the Windows 95 operating system or higher. chips in return. Although the programs of Dixon et al. (1999)simulated A 36:1bet is made by the player by placing a chip(s) di- the most common forms of gambling games found in the rectly on one number located in the middle of the board casinos, they did not simulate the more lucrative forms. A (e.g., on the 8). If the number on the wheel on which the great deal of the casino’s business, and eventual income, ball lands matches the bet the player has made, the player results from the playing of table games. These table games wins 36 times the chip(s) bet. For example,if a player bets include roulette, blackjack, and craps. In attempts to fur- 2 chips on the “8,” and if the number that comes up is 8, ther our understanding of the characteristics of casino the player receives a total of 72 chips in return. No bets games, gambling behavior, and risk-taking in general, we can be made on the 0 or the 00 spaces in our simulation. have devised a computerizedsimulationof the first of these In the casino, these bets would also take the form of a 36:1 table games, roulette. bet. Overview of the Roulette Game Program Operation The game of roulette is played with a wheel, a ball, and The program is written in Visual Basic 6.0 for IBM- a board consisting of black, red, and green numbers rang- compatible computers running the Microsoft Windows ing from 00 to 36. The object of the game is for the player 2000 or higheroperatingsystems. (Note that this software to bet chips on the number(s) on the board that he/she be- has not been tested for computers using PC emulation lieves the ball will land on when the wheel is spun. If the such as Virtual PC for Macintosh.) Visual Basic is an number that the ball lands on is a number that the player object-oriented program that uses the Windows file li- has placed a bet on, the player wins additional chips. But braries to display graphical images, play audio (.wav) and if the number on which the ball lands is not a number that video (.avi) files, and collect responses when the partici- the player has placed a bet on, the player loses all chips bet pant uses the mouse to click buttons on the computer in- for that game. To make a bet, the player places the chips terface, which makes it ideal for behavioral research on the desired location(s). Once the bets are made, the (Dixon & MacLin, 2003). Visual Basic programming dealer spins the roulette wheel and the small ball, made of code is compiled into an executablefile (.exe) and can run metal, is dropped onto the spinning wheel. The number on any IBM-compatible system with Windows 2000 or that the ball eventuallylands on is the winning number, or higherwithout the need for the user to purchase the Visual the number that has “hit.” Bets that correspond to this win- Basic programming language itself.