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Odds on: Ten ways to help prevent problem gambling

[Please note: The following article was written with Dr. Michael Auer]

Problem gambling has become a major issue in many countries worldwide. In this short article we provide ten ways to help prevent problem gambling.

Raise the minimum age of all forms of commercial gambling to 18 years – Research has consistently shown that the younger a person starts to gamble, the more likely they are to develop gambling problems. Stopping problem gambling in adolescence is a key step in preventing problem gambling in the first place. Any venue or website that hosts gambling games should have effective age verification procedures.

Restrict the most harmful types of gambling – Most research shows that gambling activities which can be gambled on continuously such as slot machines tend to be far more problematic than discontinuous games such as weekly lotteries. More harmful forms of gambling should be restricted to dedicated gambling venues rather than housed in non-dedicated gambling premises (such as supermarkets, cafes, and restaurants).

Educate players to pre-commit when engaging in the most harmful types of gambling – Ideally, the most harmful forms of gambling should have mandatory limit-setting options for players to set their own voluntary time and money limits when playing the games. Gambling operators can also use mandatory loss limits to keep gambling expenditure to a minimum.

Take responsibility for where problem gambling lies – While all individuals are ultimately responsible for their own gambling behaviour, other stakeholders – including the gambling industry – have control over the structural and situational characteristics of gambling products. Government policymakers and legislators have a responsibility to ensure that gambling products are tightly regulated and to ensure that any given jurisdiction has the infrastructure to keep gambling problems to a minimum. Gambling operators are responsible for all advertising and marketing and need to ensure that the content is socially responsible and promotes responsible gambling. Within gambling venues, all practices and procedures should be socially responsible (such as not giving free alcohol while gambling, and no ATM machines on the gaming floor).


Put social responsibility at the heart of gambling operating practice – The most socially responsible gambling operators always puts player protection and harm minimisation at the heart of their business. They need to provide all information about their products so that individuals can make an informed choice about whether to gamble in the first place. They should advertise their products responsibly and provide their clientele with tools to aid responsible gambling, and provide help and guidance for those who think they are developing a gambling problem or have one.

Raise awareness about gambling among health practitioners and the general public – Problem gambling may be perceived as a somewhat ‘grey’ area in the field of health. However, there is an urgent need to enhance awareness about gambling-related problems within the general public and the medical and health professions.

Identify at-risk players Big Data and Artificial Intelligence are common approaches applied in behavioural analysis across many industries. Online gambling and personalized land-based gambling operators can detect harmful behavioural patterns such as chasing losses or binge gambling. Such players can be excluded from direct marketing, specific types of games, and/or contacted to prevent the development of problem gambling.

Use personalized feedbackResearch across many areas such as sports, health behaviour, as well as gambling has shown that personalized feedback can effectively change behaviour. Using behavioural data available in online gambling and personalized land-based venues, gamblers can be informed in real-time about behavioural changes in order to make them more aware and use pre-commitment tools such as limit-setting and/or self-exclusion.   

Set up both general and targeted gambling prevention initiatives The goals of gambling intervention are to (i) prevent gambling-related problems, (ii) promote informed, balanced attitudes, and choices, and (iii) protect vulnerable groups. The guiding principles for action on gambling are therefore prevention, health promotion, harm reduction, and personal and social responsibility. This includes:

  • General awareness raising (e.g. public education campaigns through advertisements on television, radio, newspapers).
  • Targeted prevention (e.g. education programs and campaigns for particularly vulnerable populations such as senior citizens, adolescents, ethnic minorities).
  • Awareness raising within gambling establishments (e.g. brochures and leaflets describing problem gambling, indicative warning signs, where help for problems can be sought such as problem gambling helplines, referral service, telephone counselling web-based chatrooms for problem gamblers, and outpatient treatment).
  • Training materials (e.g. training videos about problem gambling shown in schools, job centres).

Educate and training those working in the gambling industry about problem gambling – All gaming personnel in any gambling establishments from shop retailers to croupiers should receive ongoing training regarding responsible gambling and problem gambling.

Dr. Mark Griffiths, Professor of Behavioural Addiction, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Auer, M. & Griffiths, M.D. (2013). Behavioral tracking tools, regulation and corporate social responsibility in online gambling. Gaming Law Review and Economics, 17, 579-583.

Auer, M. & Griffiths, M.D. (2013). Voluntary limit setting and player choice in most intense online gamblers: An empirical study of gambling behaviour. Journal of Gambling Studies, 29, 647-660.

Auer, M. & Griffiths, M.D. (2014). Personalised feedback in the promotion of responsible gambling: A brief overview. Responsible Gambling Review, 1, 27-36.

Auer, M., Malischnig, D. & Griffiths, M.D. (2014). Is ‘pop-up’ messaging in online slot machine gambling effective? An empirical research note. Journal of Gambling Issues, 29, 1-10.

Auer, M. & Griffiths, M.D. (2015). Testing normative and self-appraisal feedback in an online slot-machine pop-up message in a real-world setting. Frontiers in Psychology, 6, 339. doi: 10.3389/fpsyg.2015.00339.

Auer, M. & Griffiths, M.D. (2015). The use of personalized behavioral feedback for problematic online gamblers: An empirical study. Frontiers in Psychology, 6, 1406. doi: 10.3389/fpsyg.2015.01406.

Auer, M. & Griffiths, M.D. (2016). Personalized behavioral feedback for online gamblers: A real world empirical study. Frontiers in Psychology, 7, 1875. doi: 10.3389/fpsyg.2016.01875.

Griffiths, M.D. (2017). Evaluating responsible gambling tools using behavioural tracking data. Casino and Gaming International, 31, 41-45.

Griffiths, M.D. (2016). Gambling advertising, responsible gambling, and problem gambling: A brief overview. Casino and Gaming International, 27, 57-60.

Griffiths, M.D. & Auer, M. (2016). Should voluntary self-exclusion by gamblers be used as a proxy measure for problem gambling? Journal of Addiction Medicine and Therapy, 2(2), 00019.

Griffiths, M.D., Harris, A. & Auer, M. (2016). A brief overview of behavioural feedback in promoting responsible gambling. Casino and Gaming International, 26, 65-70.

Harris, A. & Griffiths, M.D. (2017). A critical review of the harm-minimisation tools available for electronic gambling. Journal of Gambling Studies, 33, 187–221.

Oehler, S., Banzer, R., Gruenerbl, A., Malischnig, D., Griffiths, M.D. & Haring, C. (2017). Principles for developing benchmark criteria for staff training in responsible gambling. Journal of Gambling Studies, 33, 167-186.

Wood, R.T.A. & Griffiths, M.D. (2015). Understanding positive play: An exploration of playing experiences and responsible gambling practices. Journal of Gambling Studies, 31, 1715-1734.

Wood, R.T.A., Shorter, G.W. & Griffiths, M.D. (2014). Rating the suitability of responsible gambling features for specific game types: A resource for optimizing responsible gambling strategy. International Journal of Mental Health and Addiction, 12, 94–112.

Out of sports: The influence of structural and situational characteristics in online sports betting

In a paper that I recently co-wrote in the Journal of Sport and Social Issues with Hibai Lopez-Gonzalez and Ana Estevez, we argued that the growing conversion of sports betting into an online activity has prompted two types of transformations in the way companies market their betting products. Firstly, the Internet has not only extended the opportunities to bet but has also changed the characteristics of the betting practice itself. Such product characteristics can be divided into two categories, namely situational and structural characteristics, that appear to be associated with factors influencing the onset and maintaining of betting as well as the difficulty of discontinuing it (the focus of this blog). Secondly, the online dimension has also enabled the proliferation of cross-marketing strategies leading to a convergence between previously independent markets or the tightening of the relationship between those with already established synergies (which I will examine in a future blog).

The internet has substantially transformed the situational and structural characteristics of sports betting. Situational factors comprise all environmental features that might make gamblers feel comfortable (both psychologically and physically) while gambling including sensory factors like colour, music, and smell in the environment, novelty of the activity, accessibility or proximity to a gambling venue, social facilitation and intrinsic association, which is defined as ‘the degree to which gambling is associated with other interests and attractions’.


New situational factors in online sports betting include: (i) easier and faster accessibility to betting opportunities; (ii) ubiquity of bettable competitions around the globe and seamless availability of those competitions around the clock; (iii) anonymity (in terms of social stigma traditionally attached to gambling) and comfortable betting from home or elsewhere via mobile devices; (iv) greater social facilitation via online communities of bettors or betting leagues organized between groups of friends; and (v) an enhanced intrinsic association of sports betting with sporting values such as health, competition, team identification and loyalty, further facilitated by the proliferation of live sport content on television and social media.

Structural factors refer to the specific characteristics or design of the gambling activity such as win probability, sound and lighting effects of the game, bet frequency (how many bets a person can place in a given period of time), loss chasing facilitation (gambling to recover lost money), jackpot size, price structure, near-miss opportunities (the psychological bias of interpreting losses as nearly wins or anticipatory of a winning streak).

New structural factors in online betting include: (i) a greater frequency of bets, with shorter intervals between bets, and shorter event durations (e.g., virtual sports), meaning faster reward mechanisms; (ii) in-play betting, which encompasses a closer connection between watching sport and betting; (iii) contextual betting, with live markets that open after specific actions (e.g. betting on the outcome of a penalty kick seconds after being awarded by the referee); (iv) greater illusion of control over the bets with new functionalities that emphasize the skills involved and diminish the role of luck, such as cash out (the person can withdraw the bet before the end of the event at the price stipulated by the betting site), accumulators (a person can aggregate multiple events in a single bet, increasing the potential return), exchange (betting against other people instead of the bookmaker); and (v) a greater integration in the betting process of the knowledge about the sport (e.g., daily fantasy sports), resulting in the gamification of the betting experience.

In a 2013 scoping study that I published with Dr. Abby McCormack in the International Journal of Cyber Behavior, Psychology and Learning, we noted that new situational and structural factors associated with Internet gambling could influence the onset of problem gambling in non-sporting gambling contexts. The relative novelty of these situational and structural characteristics affecting the wagering on sports is reflected in the scarcity of research devoted to understanding them. However, there are a few studies.

An analysis of 47,603 Bwin betting website subscribers (by Dr. Debi LaPLante and colleagues in the journal Computers in Human Behaviors) showed some interesting results in the direction of the importance of structural factors determining excessive gambling. The most involved bettors (those comprising the most active 1% of the user sample) who gambled on final outcomes did not escalate their gambling behaviour over time whereas those who gambled in-play did so. In a 2014 follow-up study in the journal Psychology of Addictive Behaviors, LaPlante and her colleagues examined the effect of in-play betting in the development of problem gambling. The researchers expanded the sample to other forms of gambling and compared the role of breadth (i.e., many different gambling forms) and depth involvement (i.e., more frequent betting) in problem gambling onset. They hypothesised that more involved users would be more likely to become problem gamblers (which was shown to be the case). For every form and gambling, when controlling for depth and breadth involvement, the model was not able to predict gambling-related problems, with one exception: in-play betting. The study suggested that a structural characteristic of a game, the live betting action, could be a precipitant, in conjunction with other determinants, of gambling disorders.

Another study by Dr. Richard LaBrie and Dr. Howard Shaffer (in a 2011 issue of Addiction Research and Theory) found that self-limiting features – in which the bettor determines a maximum amount of money to be bet – made problem gamblers bet less frequently but, in turn, increased the stakes of the bets placed. Bettors who scored high on problem gambling scales chased their losses by implementing a risk aversion strategy, placing high bets conservatively on short odds events (i.e., events with unbalanced contenders in which the outcome can more likely be determined beforehand but with a lower monetary return).

While there has been an increasing amount of research that has examined the influence of situational and structural characteristics in gambling (particularly in relation to slot machine gambling), the impact of such characteristics on online sports betting (at present) remains largely unknown.

(Please not that this article was co-written with Dr. Hibai Lopez-Gonzalez and Dr. Ana Estevez).

Dr. Mark Griffiths, Professor of Behavioural Addiction, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Griffiths, M.D. (1993). Fruit machine gambling: The importance of structural characteristics. Journal of Gambling Studies, 9, 101-120.

Griffiths, M.D. (1999). Gambling technologies: Prospects for problem gambling. Journal of Gambling Studies, 15(3), 265–283.

Griffiths, M.D. (2005). A biopsychosocial approach to addiction. Psyke & Logos, 26(1), 9–26.

Griffiths, M.D. & Auer, M. (2013) The irrelevancy of game-type in the acquisition, development and maintenance of problem gambling. Frontiers in Psychology, 3, (621). doi: 10.3389/fpsyg.2012.00621.

LaBrie, R. & Shaffer, H.J. (2011). Identifying behavioral markers of disordered Internet sports gambling. Addiction Research & Theory, 19(1), 56–65.

LaPlante, D., Nelson, S.E. & Gray, H.M. (2014). Breadth and depth involvement: Understanding Internet gambling involvement and its relationship to gambling problems. Psychology of Addictive Behaviors, 28(2), 396-403.

LaPlante, D.A., Schumann, A., LaBrie, R.A., et al. (2008). Population trends in Internet sports gambling. Computers in Human Behavior, 24(5), 2399–2414.

Leino, T., Torsheim, T., Blaszczynski, A., Griffiths, M.D., Mentzoni, R., Pallesen, S. & Molde, H. (2015). The relationship between structural characteristics and gambling behavior: A population based study. Journal of Gambling Studies, 31, 1297-1315.

Lopez-Gonzalez, H., Estevez, A. & Griffiths, M.D. (2017). Marketing and advertising online sports betting: A problem gambling perspective. Journal of Sport and Social Issues, in press.

Lopez-Gonzalez, H. & Griffiths, M.D. (2016). Is European online gambling regulation adequately addressing in-play betting advertising? Gaming Law Review and Economics, 20, 495-503.

Lopez-Gonzalez, H. & Griffiths, M.D. (2017). Understanding the convergence of online sports betting markets. International Review for the Sociology of Sport, in press.

Lopez-Gonzalez, H. & Griffiths, M.D. (2017). ‘Cashing out’ in sports betting: Implications for problem gambling and regulation. Gaming Law Review and Economics, in press.

McCormack, A. & Griffiths, M.D. (2013). A scoping study of the structural and situational characteristics of internet gambling., 3(1), 29–49.

Parke, J. & Griffiths, M.D. (2006). The psychology of the fruit machine: The role of structural characteristics (revisited). International Journal of Mental Health and Addiction, 4, 151-179.

Parke, J. & Griffiths, M.D. (2007). The role of structural characteristics in gambling.  In G. Smith, D. Hodgins & R. Williams (Eds.), Research and Measurement Issues in Gambling Studies (pp.211-243). New York: Elsevier.

Against all odds: The rise and rise of gambling

In many areas of the world, gambling has become a popular activity. Almost all national surveys into gambling have concluded that most people have gambled at some point in their lives, there are more gamblers than non-gamblers, but that most participants gamble infrequently. Commissions and official government reviews in a number of countries including the United States, United Kingdom, Australia and New Zealand have all concluded that increased gambling availability has led to an increase in problem gambling. Estimates of the number of problem gamblers vary from country to country but most countries that have carried out national prevalence surveys suggest around 0.5%-2% of individuals have a gambling problem.

In May 2013, the new criteria for problem gambling (now called ‘Gambling Disorder’) were published in the fifth edition of the American Psychiatric Association’s Diagnostic and Statistical Manual for Mental Disorders (DSM-5), and for the very first time, problem gambling was included in the section ‘Substance-related and Addiction Disorders’ (rather than in the section on impulse control disorders). Also included in the Appendix of the DSM-5 as a potential addiction was Internet Gaming Disorder (i.e., online video game addiction). Although most of us in the field had been conceptualizing problematic gambling and video gaming as addictions for many years, this was arguably the first time that an established medical body had described them as such. For me, gambling and gaming addictions should not be considered any differently from other more traditional chemical addictions (e.g., alcohol addiction, nicotine addiction). Consequently, there is no theoretical reason why other problematic and excessive activities that do not involve the ingestion of a psychoactive substance cannot be deemed as legitimate behavioural addictions in the years to come (e.g., shopping addiction, sex addiction, work addiction, exercise addiction, etc.).

Gambling is a multifaceted rather than unitary phenomenon. Consequently, many factors are involved in the acquisition, development and maintenance of gambling behaviour. Such factors include an individual’s biological and genetic predisposition, their social environment, psychological variables (personality characteristics, attitudes, expectations, beliefs, etc.), macro-situational characteristics (how much gambling is marketed and advertised, the number of gambling venues within a jurisdiction, where the gambling venue is located), micro-situational characteristics of the gambling environment (on-site cash machine, provision of free alcohol, floor layout etc.), and the structural characteristics of the gambling activity itself (jackpot size, stake size, the number of times a individual can gamble in a given time frame, etc.). Most research has tended to concentrate on individual characteristics (personality, genetics, family and peer influence) rather than situational and structural characteristics.

The introduction of national lotteries, the proliferation of slot machines, the expansion of casinos, and the introduction of new media in which to gamble (e.g., Internet gambling, mobile phone gambling, interactive television gambling, gambling via social networking sites), has greatly increased the accessibility and popularity of gambling worldwide, and as a result, the number of people seeking assistance for gambling-related problems. In addition, the rise of remote gambling via the internet and mobile phones has arguably changed the psychosocial nature of gambling. I have also published a number of studies showing that to vulnerable and susceptible individuals (e.g., problem gamblers, minors, the intoxicated, etc.), the medium of the internet may facilitate and fuel problematic and addictive behaviours.

There are many known factors that make online activity potentially problematic to a minority of individuals. This includes factors such as easy accessibility, affordability, anonymity, convenience, escape, and disinhibition. Some of these factors can change the psychological experience of gambling. For instance, gambling with virtual representations of money online lower the psychological value of the money and people tend to spend more with virtual representations of money than if they were gambling with physical money. Also, when people lose money online it is a different psychological experience because no-one can see anyone losing face-to-face. As a result, there is less guilt and embarrassment about losing and vulnerable individuals may be tempted to spend more time and money than they had originally intended.

One very salient trend that has implications for gambling (and arguably problem gambling) is that technology hardware is becoming increasingly convergent (e.g., internet access via smartphones and interactive television) and there is increasing multi-media integration such as gambling and video gaming via social networking sites. As a consequence, people of all ages are spending more time interacting with technology in the form of internet use, playing videogames, watching interactive television, mobile phone use, social networking, etc. In addition to convergent hardware, there is also convergent content. This includes some forms of gambling including video game elements, video games including gambling elements, online penny auctions that have gambling elements, and television programming with gambling-like elements.

One of the key drivers behind the increased numbers of people gambling online and using social networking sites is the rise of mobile gambling and gaming. Compared to internet gambling, mobile gambling is still a relatively untapped area but the functional capabilities of mobile phones and other mobile devices are improving all the time. There are now hundreds of gambling companies that provide casino-style games to be downloaded onto the gambler’s smartphone or mobile device (e.g., tablet or laptop). This will have implications for the psychosocial impact of gambling and will need monitoring. Like online gambling, mobile gaming has the capacity to completely change the way people think about gambling and betting. Mobile phones provide the convenience of making bets or gambling from wherever the person is, even if they are on the move.

One of the most noticeable changes in gambling over the last few years – and inextricably linked to the rise of mobile gaming – has been the large increase of in-play sports betting. Gamblers can now typically bet on over 60 ‘in-play’ markets while watching a sports event (such as a soccer match). For instance, during a soccer game, gamblers can bet on who is going to score the first goal, what the score will be after 30 minutes of play, how many yellow cards will be given during them game and/or in what minute of the second half will the first free kick be awarded. Live betting is going to become a critical activity in the success of the future online and mobile gambling markets.

The most salient implication of ‘in-play’ sports betting is that it has taken what was traditionally a discontinuous form of gambling – where an individual makes one bet every Saturday on the result of the game – to one where an individual can gamble again and again and again. Gaming operators have quickly capitalized on the increasing amount of televised sport. In contemporary society, where there is a live sporting event, there will always be a betting consumer. ‘In-play’ betting companies have both catered for the natural betting demand but introduced new gamblers in the process. If the reward for gambling only happens once or twice a week, it is completely impossible to develop problems and/or become addicted. ‘In-play’ has changed that because there are soccer matches on almost every day of the week making a daily two-hour plus period of betting seven days a week.

New technologies in the form of behavioural tracking have helped online gambling companies keep track of players by noting (among many other things) what games they are playing, the time spent playing, the denomination of the gambles made, and their wins and losses. Although such technologies can potentially be used to exploit gamblers (e.g., targeting the heaviest spenders with direct marketing promotions to gamble even more), such technologies can also be used to help gamblers that may have difficulties stopping and/or limiting their gambling behaviour. Over the past few years, innovative social responsibility tools that track player behaviour with the aim of preventing problem gambling have been developed. These new tools are providing insights about problematic gambling behaviour. A number of European jurisdictions (such as Germany and The Netherlands) are now considering whether such tools should be mandatory for gaming operators to use especially as such tools are already being used in Sweden, Norway, Finland and Austria.

Although gamblers are ultimately responsible for their own behaviour, gambling can be minimised via both governmental policy initiatives (age restrictions, marketing and advertising restrictions, no gaming licenses unless operators display the highest standards of social responsibility to their clientele, etc.) and gaming operator initiatives (self-exclusion programs, information about games so gamblers can make informed choices, limit-setting tools that allow gamblers to set time and money loss limits, staff training on responsible gambling, referral to gambling treatment providers, etc.). Problem gambling can never be totally eliminated but harm minimisation practices can be put in place to keep the problem to a minimum. Treatment for gambling addiction should be free and paid for by gambling industry profits (either in the form of voluntary donations to a charitable trust or – if that doesn’t work – a statutory levy). In short, any jurisdiction that has legalised and liberalised gambling has a duty of care to put a national social responsibility infrastructure in place to prevent, minimise, and treat problem gambling as they would with any other consumptive and potentially addictive behaviour (e.g., drinking alcohol, smoking cigarettes, etc.)

Please note: A version of this article first appeared in Science and Technology (Pan European Networks) magazine (Volume 15, pages 153-155).

Dr. Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Griffiths, M.D. (2003). Internet gambling: Issues, concerns and recommendations. CyberPsychology and Behavior, 6, 557-568.

Griffiths, M.D. (2005). A ‘components’ model of addiction within a biopsychosocial framework. Journal of Substance Use, 10, 191-197.

Griffiths, M.D. (2011). Gaming convergence: Further legal issues and psychosocial impact. Gaming Law Review and Economics, 14, 461-464.

Griffiths, M.D. (2012). Mind games (A brief psychosocial overview of in-play betting). i-Gaming Business Affiliate, June/July, 44.

Griffiths, M.D. (2012). Internet gambling, player protection and social responsibility. In R. Williams, R. Wood & J. Parke (Ed.), Routledge Handbook of Internet Gambling (pp.227-249). London: Routledge.

Griffiths, M.D., King, D.L. & Delfabbro, P.H. (2014). The technological convergence of gambling and gaming practices. In Richard, D.C.S., Blaszczynski, A. & Nower, L. (Eds.). The Wiley-Blackwell Handbook of Disordered Gambling (pp. 327-346). Chichester: Wiley.

Griffiths, M.D. & Parke, J. (2003). The environmental psychology of gambling. In G. Reith (Ed.), Gambling: Who wins? Who Loses? (pp. 277-292). New York: Prometheus Books.

Kuss, D.J. & Griffiths, M.D. (2012).  Internet gambling behavior. In Z. Yan (Ed.), Encyclopedia of Cyber Behavior (pp.735-753). Pennsylvania: IGI Global.

McCormack, A. & Griffiths, M.D. (2013). A scoping study of the structural and situational characteristics of internet gambling. International Journal of Cyber Behavior, Psychology and Learning, 3(1), 29-49.

Meyer, G., Hayer, T. & Griffiths, M.D. (2009). Problem Gaming in Europe: Challenges, Prevention, and Interventions. New York: Springer.

Parke, J. & Griffiths, M.D. (2007). The role of structural characteristics in gambling. In G. Smith, D. Hodgins & R. Williams (Eds.), Research and Measurement Issues in Gambling Studies (pp.211-243). New York: Elsevier.

Pontes, H. & Griffiths, M.D. (2014). The assessment of internet gaming disorder in clinical research. Clinical Research and Regulatory Affairs, 31(2-4), 35-48.

Zangeneh, M., Griffiths, M.D. & Parke, J. (2008). The marketing of gambling. In Zangeneh, M., Blaszczynski, A., and Turner, N. (Eds.), In The Pursuit Of Winning (pp. 135-153). New York: Springer.

Prophet share: A case study of ‘addiction to fortune telling’

In the latest issue of the Journal of Behavioral Addictions, there are two papers that I co-authored on muscle dysmorphia as an addiction (see ‘Further reading’ below). The reason I mention this is because in the same issue there was a case study report by Dr. Marie Grall-Bronnec and her colleagues of a woman (Helen) that was ‘addicted’ to fortune tellers. As noted in their paper:

“Clairvoyance consulting, also known as fortune teller consulting, is a behavior that may seem harmless, but can also become excessive. Fortune telling is defined as the practice of predicting information about a person’s life, using for example…astrology, cartomancy or crystallomancy”.

As I have noted in a number of my previous blogs, I subscribe to the view that if there are clinical criteria for addiction and a behaviour fulfils the criteria, it should be classed as an addiction (irrespective of the behaviour). This has led to accusations of me “watering down the concept of addiction” because such criteria have been applied to behaviours as diverse as gardening and chewing gum. According to the authors of the ‘fortune telling addiction’ paper:

“Helen is a 45-year-old woman who declares early on suffering from ‘a clairvoyance addiction’…She has no particular medical history, except for two major depression episodes after romantic breakups, and does not take any medication. She regularly sees a psychiatrist for support psychotherapy because of negative life events (sexual abuse and death in her family). She is divorced and does not have any children. Her career as a manager seems to fully satisfy her. She decides to seek treatment on account of her excessive financial expenditures due to the consultation of fortune tellers. Another motivation that explains her decision is her age. Indeed, she says she is entering a new phase in her life, after renouncing to the idea of becoming a mother one day”.

According to the paper, Helen had been consulting fortune tellers since she was 19 years old. She started using such people for educational and career advice as she claimed that she was poor at reaching important decisions herself and thought the life choices she made would be wrong. The authors noted that her first meeting with a clairvoyant was an event that gave her a feeling of reassurance. In her mid-twenties, her visits to clairvoyants escalated significantly and ended up losing control of her use of fortune telling”. At that particular time, she was visiting clairvoyants to get relationship advice from them (e.g., “Does he really love me?” and “How long will our relationship last?”). Her current ‘addiction to clairvoyants’ dates back to her mid- to late-30s when she got divorced after the failure of her marriage:

“She repeatedly returned to fortune telling to reassure herself about the future of her relationship, and increasingly so as it deteriorated. The breakup worsened the disorder. Since her divorce, she consults fortune tellers – not always the same person – on the phone or online, in a compulsive way, more and more often (up to every day), for longer and longer periods of time (up to 8 hours a day) and spends each time more and more money (up to 200 euros per session). As she is never satisfied with the fortune tellers’ predictions, she will consult again very soon after the latest call or connection. Every choice she has to make, from the most trivial (going to the movies) to the most important (making relationship decisions), leads her to irrationally consult a fortune teller”

Before each consultation she said he got very excited at the prospect and that the experience relieved all of her psychological discomfort (at least in the short-term). However, not long after consultations she would feel incredibly guilty. The paper also reported that during consultations with the fortune tellers, she was totally convinced that they could see her future and that their predictions would come true. He authors went on to report:

“This excessive behavior gives her some kind of reassurance and allows her to make up for her lack of self-confidence. In that sense, the excessive behavior could be considered as an attempt at self-medication or as a way to cope with negative emotions. However, Helen knows that her belief in the fortune tellers’ ability to predict the future is completely irrational. This brings major adverse consequences, particularly in financial terms: despite a comfortable income, she is indebted. She also says having low self-esteem, due to her in- ability to resist her strong urge to consult fortune tellers, and due to her being isolated from the others because of the time spent consulting fortune tellers. Helen succeeds in limiting the consultation of fortune tellers during short periods of time, when her financial situation becomes too critical”.

The authors of the report also used different sets of addiction criteria to determine whether Helen was truly addicted to consulting clairvoyants. They also used my own six criteria (salience, mood modification, tolerance, withdrawal, conflict, and relapse). Here are the authors own description of the behaviour using my components model:

  • Salience: “Consulting fortune tellers becomes the most important activity in Helen’s life and dominates her thinking (preoccupation and cognitive distortions), feelings (cravings) and behavior (she has progressively quit all her leisure activities, particularly going out with friends)”.
  • Mood modification: “Helen says feeling excitement before each consultation, but also feels nervous tension and anxiety. This excessive behavior gives her some kind of reassurance and the excessive behavior could be considered as an attempt at self-medication or a way to cope with negative emotions”.
  • Tolerance: “Over time, Helen has been feeling a growing need to consult fortune tellers, and the consultations have to last longer to obtain the same effect of relief”.
  • Withdrawal: “When she attempts to resist the urge to consult or has to refrain from consulting fortune tellers (in the case of her financial situation being too critical, for example), she feels tense and nervous”.
  • Conflict: “Helen knows that her use of fortune telling is problematic, and that it brings very negative consequences. However, she cannot refrain from consulting fortune tellers, leading to an intra-psychic conflict and guilt”.
  • Relapse: “Over the years, Helen has made repeated efforts to reduce and stop this problematic behavior. Her clinical course is characterized by relapses and remissions”.

Based on the evidence presented, there is clear evidence that Helen’s behaviour was problematic. Whether it was genuinely addictive is debatable but the authors provided some evidence that (in this case at least) the behaviour appeared to include some addictive aspects. The authors conclude that in addition to individual risk factors, other situational and structural characteristics may have played a role in the development of problematic behaviour concerning Helen’s ‘addiction’:

Regarding the risk factors related to the object of addiction (i.e. fortune telling use), one might mention, inter alia, the possibility to consult online, which guarantees anonymity. Furthermore, the Internet increases both accessibility and availability. Finally, the money spent during fortune telling sessions seems virtual, which makes it all the more easy to spend. Increased risks related to the Internet have already been described on gambling (Griffiths, Wardle, Orford, Sproston & Erens, 2009). Regarding socio-environmental risk factors, today’s society encourages the need for control and does not give way to uncertainty. In Helen’s case, all the conditions were met for the fortune telling use to become excessive, and we are tempted to conclude that it is an addictive-like phenomenon”.

Dr. Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Foster, A.C., Shorter, G.W. & Griffiths, M.D. (2015). Muscle Dysmorphia: Could it be classified as an Addiction to Body Image? Journal of Behavioral Addictions, 4, 1-5.

Grall-bronnec, M. Bulteau, S., Victorri-Vigneau, C., Bouju, G. & Sauvaget, A. (2015). Fortune telling addiction: Unfortunately a serious topic about a case report. Journal of Behavioral Addiction, 4, 27-31.

Griffiths, M.D. (1996). Behavioural addictions: An issue for everybody? Journal of Workplace Learning, 8(3), 19-25.

Griffiths, M. (2005). A “components” model of addiction within a biopsychosocial framework. Journal of Substance Use, 10, 191–197.

Griffiths, M.D., Foster, A.C. & Shorter, G.W. (2015). Muscle dysmorphia as an addiction: A response to Nieuwoudt (2015) and Grant (2015). Journal of Behavioral Addictions, 4, 11-13.

Griffiths, M., Wardle, H., Orford, J., Sproston, K. & Erens, B. (2009). Sociodemographic correlates of internet gambling: Findings from the 2007 British gambling prevalence survey. CyberPsychology and Behavior, 12, 199–202.

Hughes, M., Behanna, R. & Signorella, M. L. (2001). Perceived ac- curacy of fortune telling and belief in the paranormal. Journal of Social Psychology, 141(1), 159–160.

Shein, P. P., Li, Y. Y. & Huang, T. C. (2014). Relationship between scientific knowledge and fortune-telling. Public Understanding of Science, 23(7), 780–796.

Coming a part of the themes: The psychology of familiarity in gambling

Have you seen slot machines featuring Spiderman? Or the ones based on the Monopoly board game? Or the slots that have pictures of Lara Croft from the Tomb Raider video game? Most gaming operators will appreciate that all of these images have a strong brand presence, and that it is one of the main reasons for themed games. However, a more basic marketing tactic is being used here – the psychology of familiarity. This is used throughout the gaming industry but is most common on slot machines, online games, and scratchcards. For instance, Camelot’s scratchcards in the UK have featured film tie-ins (e.g., James Bond, Pirates of the Caribbean, Star Wars), and popular games (e.g., Connect Four).

But this wasn’t always the case. Back in the late 1980s I did some research on the names that gaming designers and operators gave their slot machines. One of the more interesting findings I reported in one of my academic papers was that over 50% of all machine names that I came across in amusement arcades had some reference to money on them (such as ‘Cashpoint’, ‘Cashline’, ‘Action Bank’, Piggy Bank’, ‘Money Belt’ etc.). Psychologically, all of these machine names gave the impression that this was where a player could get money from – not where they would lose it! Other categories of machine names included those with some reference to skill on them (‘Fruitskill’, ‘Skillchance’) suggesting that machine playing was a skillful activity and that gamblers could perhaps beat the machine. Other machines had what I called “acoustically attractive” names (Nifty Fifty, Naughty But Nice) or puns (Reel Fun, Reel Money). Since making these observations, I have always been interested in the subtle techniques that the gaming industry uses in getting the punter to play on their products. The psychology of gambling – or rather the psychology of gambling marketing – has come a long way in the last decade.

As I’ve already said, one of the techniques that the gaming industry uses (whether they realise it or not) is the psychology of familiarity. Gaming operators and marketers have realised that one weapon in their marketing armory is to design products which appear familiar before a player has ever even played on them – something that can partly be achieved through the name or theme of the slot machine. The examples I gave above showed that the names of slot machines appear to be important in impression formation. It is highly unlikely that the names of slot machines have any influence on gambling behaviour per se. However, when tied in with recent research on the psychology of familiarity, the names of machines do seem to be critically important – particularly in terms of gambling acquisition (that is, getting people to gamble in the first place).

Nowadays, slot machines are often named after a famous person (the Elvis Presley machines appear very popular in one of my local casinos), place, event, video game, board game, television show or film. Not only is this something that is familiar to the gambler but may also be something that the potential gamblers might like or affiliate themselves with (such as James Bond). This is different from a simple naming effect in that the machine’s theme may encompass the whole play of the machine, including its features, the sound effects (e.g., the theme tune to popular television programmes like Coronation Street or Eastenders), and light/colour effects. By using well-known and common themes, gamblers may be more likely to spend time and money playing them.

Some of the most popular UK slot machines are those that feature The Simpsons. There are many possible reasons why a gambler might be more likely to play on a Simpsons’ machine. The Simpsons have mass appeal and popularity across all ages and across gender. The machines are celebrity-endorsed and players may place trust in a ‘quality’ brand like The Simpsons. Gamblers may also hope that knowledge of the characters will help in the playing of the game. On a basic level, it might simply be that the game play of The Simpsons is more exciting, and that the sound effects and features are novel, cute and/or more humorous than other machines. There are many cases similar to this one where it could be speculated that the slot machine becomes so much more inducing because it represents something that is familiar and/or special to the gambler.

Familiarity is a very important psychological aspect of why themed slot machines have been more prominent over the last decade. Familiar themes have the capacity to induce a ‘psycho-structural interaction’ between the gambler and the gambling activity. This is where the gambler’s own psychology interacts with the machine’s structural characteristics and produces different consequences for each person depending upon what the feature means to them personally. If the themes are increasingly familiar, a gambler might be more likely to persevere with the complexities of a machine. Gamblers may find it more enjoyable because they can easily interact with recognizable images they experience. Therefore, the use of familiar themes may have a very persuasive effect, leading to an increase in the number of people using them, and the money they spend. Whilst there are many other aspects that influence an individual’s decision to gamble, the possible persuasive nature of the themes should not be underestimated.

As you may have already gathered, there is a strong overlap between the psychology of familiarity, branding, and the psychology of persuasion. In very simple terms, a gambler must be exposed to the product and be aware of its presence before they can even make the decision to gamble. This is relatively easy to achieve given the ubiquity of slot machines and the fact that current machines will use any number of techniques to grab a potential player’s attention. These include television or film theme tunes, bright flashing lights, and/or pictures or voices of celebrities. Once a gambler’s attention has been gained, the product must be likeable and familiar enough for them to think about gambling and wanting to interact with the machine further. Immediately familiar images and sounds are likely to lead to a much quicker decision to gamble. All which goes to show – the gaming industry knows what it is doing!

Dr. Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Griffiths, M.D. (1993). Fruit machine gambling: The importance of structural characteristics. Journal of Gambling Studies, 9, 101-120.

Griffiths, M.D. (2007). Brand psychology: Social acceptability and familiarity that breeds trust and loyalty.Casino and Gaming International, 3(3), 69-72.

Griffiths, M.D. & Dunbar, D. (1997). The role of familiarity in fruit machine gambling. Society for the Study of Gambling Newsletter, 29, 15-20.

Griffiths, M.D. & Parke, J. (2003). The environmental psychology of gambling. In G. Reith (Ed.), Gambling: Who wins? Who Loses? (pp. 277-292).New York: Prometheus Books.

King, D.L., Delfabbro, P.H. & Griffiths, M.D. (2010). Video game structural characteristics: A new psychological taxonomy. International Journal of Mental Health and Addiction, 8, 90-106.

Parke, J. & Griffiths, M.D. (2006). The psychology of the fruit machine: The role of structural characteristics (revisited). International Journal of Mental Health and Addiction, 4, 151-179.

Parke, J. & Griffiths, M.D. (2007). The role of structural characteristics in gambling. In G. Smith, D. Hodgins & R. Williams (Eds.), Research and Measurement Issues in Gambling Studies (pp.211-243). New York: Elsevier.

Wood, R.T.A., Griffiths, M.D., Chappell, D. & Davies, M.N.O. (2004). The structural characteristics of video games: A psycho-structural analysis. CyberPsychology and Behavior, 7, 1-10.

Sound ideas: A brief look at the effect of music on gambling behaviour

Throughout my academic career, I have always been interested in how the design of environments affects human behaviour. Given that my primary research area is the psychology of gambling and that my most passionate hobby is listening to music, it probably won’t come as a surprise that I have carried out research into the effect of music on gambling behaviour.

The effect of music has been studied extensively in commercial contexts (particularly advertising and retailing). Many research studies have shown that music has the capacity to affect consumers’ perceptions of a particular environment, their intended and actual purchase behaviour, and time spent in a particular environment. Advertisers and marketers use such knowledge to help target their consumer group. Psychologists Adrian North and David Hargreaves have noted in many of their papers that music may have the capacity to modify psychological arousal or induce relaxation. A number of studies have supported this claim through various investigations into the arousal of music.

Highly arousing music has been characterised as loud, unpredictable and with a quick tempo. Low arousing music in contrast is soft, predictable, and has a slower tempo. The more the music is able to produce arousal in individuals, the more pleasurable it is for them, and the more likely it will be their preference. Musical tempo is another area within the field of music that has generated empirical research. A variety of reports from participants and consumers have described fast tempo music with a variety of adjectives, indicating it as happier, pleasant, joyous, exhilarating. Studies manipulating the tempo of music have found that faster music leads to more positive judgements of advertisements, enhances effects on the performance of tasks, leads to faster movement, and higher arousal levels. Slow music has the opposite effects resulting in more relaxing, solemn adjectives being used when participants described it.

As both a structural and situational characteristic in gambling behaviour, the role of music has become more apparent in the last decade. Many slot machines now have musical interludes. This makes them generally more appealing, especially if they are familiar. Researchers (including myself) have consistently argued that sound effects can contribute to the encouragement of gambling.

Back in 2003, Dr. Jonathan Parke and myself published a book chapter examining the environmental psychology of gambling in the book Gambling: Who Wins? Who Loses? (edited by the sociologist Gerda Reith). A small part of that review speculatively examined the role of music in facilitating gambling behaviour. We noted that at the time we wrote the review, no research has been carried out on the topic (and that research was obviously needed). A couple of years later, we published a paper in the Journal of Gambling Issues and reported a number of observations based on our experiences of enaging in participant and non-participant observation in amusement arcades and other gambling venues.

We argued that auditory effects have the capacity to make a slot machine more ”aesthetically appealing” to individuals and this differentiation could be a deciding factor when choosing a machine. We also hypothesized that music has the potential to facilitate, stimulate, maintain and exacerbate gambling behaviour in some individuals. This could be due to the fact that familiar music may induce a feeling of enjoyment as it is recognisable to the individual and thus may entice them into playing (something that I had noted in an earlier paper that I wrote with David Dunbar in a 1997 issue of the Society for the Study of Gambling Newsletter). The music played when one wins is distinctive and memorable and could also lead to further plays. In short, music has the capability to increase confidence, modulate arousal and relaxation and help the player to disregard previous losses.

In 2007, I published a study in the journal International Gambling Studies that I carried out with Laura Dixon and Dr. Richard Trigg investigating the role of music in gambling behaviour. In our experiment, 60 participants played virtual roulette in one of three conditions.The three conditions were (i) no music, (ii) slow tempo music,and (iii) fast music (20 participants in each condition). Tengames of roulette were played with speed of betting, amountspent across high, medium and low-level risk bets and totalamount spent recorded. Their results showed that speed ofbetting was influenced by musical tempo with faster bettingoccurring while listening to higher tempo music.However, there was no relationship between musical tempo and either the size of the bet or the overall amountspent. Although not carried out in a casino, we believed our findingsprovided valuable insight into how background music can bemanipulated to increase the speed of gambling.

In 2010, along with Jenny Spenwyn and Dr. Doug Barrett, I published another study examining the effect of music on gambling in the International Journal of Mental Health and Addiction. This study (as far as we are aware) was the first ever empirical study to examine the combined effects of both music and light on gambling behaviour. While playing an online version of roulette, 56 participants took part in one of four experimental conditions (14 participants in each condition); (1) gambling with fast tempo music under normal (white) light, (2) gambling with fast tempo music under red light, (3) gambling with slow tempo music under normal (white) light, and (4) gambling with slow tempo music under red light. Risk (i.e., the amount of money spent) per spin and speed of bets were measured as indicators of gambling behaviour. We found significant effects for speed of bets in relation to musical tempo, but not light. We also found a significant interaction between light and music for speed of bets. In short, we found that fast tempo music under red light resulted in individuals gambling faster gambling.

Most recently, some of my research colleagues in Norway, led by Dr. Rune Mentzoni, published a paper in the Journal of Behavioral Addictions that also examined music’s effect of gambling behaviour. Like our studies, they carried out a laboratory experiment. Their study comprised101 undergraduate students who played a computerized gambling task inwhich either a high-tempo or a low-tempo musical soundtrack was present. It was reported that: low-tempo music was associated with increased gambling persistence in terms of overall number of bets placed, whereas high-tempo music was associated with intensified gambling in terms of faster reaction time per placed bet. Based on their results, they concluded that high-tempo music is associated with more risky gambling behaviour (by increasing gambling persistence and by reducing reaction time for bets placed).

From the empirical literature published so far, there does appear to be some evidence to suggest that the gambling environment may be manipulated by the use of sound of music (as well as other characteristics such as light and colour) and that such situational characteristics may affect gambling behaviour. However, the empirical base, is limited and further research is needed before reaching any definitive conclusions.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading 

Caldwell, C. & Hibbert, S.A. (1999). “Play that one again: The effect of music tempo on consumer behaviour in a restaurant. European Advances in Consumer Research, 4, 58-62.

Dixon, L., Trigg, R. & Griffiths, M. (2007). An empirical investigation of music and gambling behaviour. International Gambling Studies, 7, (3), 315-326.

Dube, L., Chebat, J.C. & Morin, S. (1995). The effects of background music on consumers desire to affiliate in buyer- seller interactions”, Psychology and Marketing, 12, 305-319.

Griffiths, M.D. & Dunbar, D. (1997). The role of familiarity in fruit machine gambling. Society for the Study of Gambling Newsletter, 29, 15-20.

Griffiths, M.D. & Parke, J. (2003). The environmental psychology of gambling. In G. Reith (Ed), Gambling: Who wins? Who loses? pp. 277-292. New York: Prometheus Books.

Griffiths, M.D. & Parke, J. (2005). The psychology of music in gambling environments: an observational research note. Journal of Gambling Issues, 13. Available at:

Hebert, S., Beland, R., Dionne-Fournelle, O., Crete, M. & Lupien, S.J. (2004). Psychological stress response to video game playing: the contribution of built in music. Life Sciences, 76, 2371-2380.

Kellaris, J.J. & Kent, R.J. (1993). An exploratory investigation of responses elicited by music varying in tempo, tonality, and texture. Journal of Consumer Psychology, 2, 381-402.

Mentzoni, R. A., Laberg, J. C., Brunborg, G. S., Molde, H., & Pallesen, S. (2014). Type of musical soundtrack affects behavior in gambling. Journal of Behavioral Addictions, DOI: 10.1556/JBA.3.2014.006.

Milliman, R.E. (1982). Using background music to affect the behaviour of supermarket shoppers. Journal of Marketing, 46, 86-91.

Milliman, R.E. (1986). “The influence of background music on the behaviour of restaurant patrons. Journal of Consumer Research, 13, 286-289.

North, A.C., & Hargreaves, D.J. (1997). Experimental aesthetics and everyday music listening. In D.J. Hargreaves & A.C. North (Eds.), The Social Psychology of Music. pp.84-103. Oxford: Oxford University Press.

Parke, J. & Griffiths, M.D. (2006). The psychology of the fruit machine: The role of structural characteristics re-visited. International Journal of Mental Health and Addiction, 4, 151-179.

Parke, J. & Griffiths, M.D. (2007). The role of structural characteristics in gambling. In G. Smith, D. Hodgins & R. Williams (Eds.), Research and Measurement Issues in Gambling Studies. pp.211-243. New York: Elsevier.

Spenwyn, J., Barrett, D.K.R. & Griffiths, M.D. (2010). The role of lights and music in gambling behavior: An empirical pilot study. International Journal of Mental Health and Addiction, 8, 107-118.

The prize and lows: What is the effect of winning large jackpots on human behaviour?

Over the last two decades I have written a lot of research papers about the structural characteristics of gambling and their effect on subsequent human behaviour. One of the most basic structural characteristics that may determine whether someone gambles on a particular type of game in the first place is the size of the jackpot that a game has to offer. Most of the research in this area has been carried out on lottery gambling as this form of gambling tends to have the largest jackpots. However, there is no reason to assume that these general findings should not be any different in other types of gambling such as winning a million dollars on a slot machine.

As I have noted in some of my previous blogs, structural characteristics in gambling are typically those features of a game that are responsible for reinforcement, may satisfy gamblers’ needs and may (for some ‘vulnerable’ players) facilitate excessive gambling. Such features include the event frequency of the game, jackpot size, stake size, the probability of winning, and the use of ‘near misses’ and other ‘illusion of control’ elements. By identifying particular structural characteristics it is possible for researchers (and the gaming industry) to see how needs are identified, to see how information about gambling is perceived, and to see how thoughts about gambling are influenced.

Showing the existence of such relationships has great practical importance as potentially ‘risky’ forms of gambling can be identified. Furthermore, by identifying particular structural characteristics it may be possible to understand more about gambling motivations and behaviour, which can have useful clinical, academic and commercial implications. It has been widely accepted that structural characteristics have a role in the acquisition, development, and maintenance of gambling behaviour. However, it would appear that the role of structural characteristics has become even more significant within the past decade and has led to increased empirical research on structural gaming features.

One of the main reasons that people gamble is that it provides the chance of winning money. But does winning large amounts of money actually make people happy? People often dream about winning large life changing amounts of money on games like a national lottery. The winners hopefully look forward to a long life of everlasting happiness although studies have found that lottery winners are euphoric very briefly before they settle back to their normal level of happiness or unhappiness. This is because happiness is relative. There is a popular belief by some psychologists that in the long run, winning large amounts of money on gambling activities will not make someone happy. Researchers who study happiness say that everyone has a certain level of happiness that stays relatively constant but can be changed by particular events that make the person happy or sad.

Thankfully, this change only lasts for a short period of time. For instance, if someone is a generally happy person and a close relative dies, research shows that after a few months or so, the person will go back to the same happiness level that they were previously. However, this works the other way too. If a person is not very happy in their day-to-day life, they could win a large amount of money gambling and they would probably be happy for a couple months but then they would ‘level out’ and go back to life at their normal unhappiness level.

Back in 1978, research by Dr. Phillip Brickman and his colleagues in the Journal of Personality and Social Psychology compared a sample of 22 major lottery winners with 22 controls and also with a group of 29 paralysed accident victims. They found that major lottery winners were no happier than control groups. Another 1994 study by Dr. G. Eckblad and Dr. A. von der Lippe (in the Journal of Gambling Studies) investigated 261 Norwegian lottery winners who had won more than one million Norwegian Krone (approximately £100,000). There were few typical emotional reactions to winning apart from moderate happiness and relief. Their gambling was modest both before and after winning the lottery and their experiences with winning were almost all positive. The researchers reported that their quality of life was stable or had improved. They concluded that their results support earlier research by Dr. Roy Kaplan (also published in the Journal of Gambling Studies) who found that that lottery winners are not gamblers, but self-controlled realists.

One of the infamous questions in social science is whether money makes people happy. In 2001, Dr. Jonathan Gardner and Dr. Andrew Oswald carried out a longitudinal study on the psychologicalhealth and reported happiness of approximately 9,000 randomly chosen people. Their research reported that those whoreceived financial windfalls (i.e., by large gambling wins or receiving an inheritance) hadhigher mental wellbeing in the following year. In another longitudinal data study on a random sample of Britons who received medium-sized lottery wins of between £1000 and £120,000, the same authors compared lottery winners with two control groups (one with no gambling wins and the other with small gambling wins). They reported that big lottery winners went on to exhibit significantly better psychological health. Two years after a lottery win there was an improvement in mental wellbeing using the General Health Questionnaire. Other data (published in 2009) have also been analysed by Dr. Benedict Apouey and Dr. Andrew Clark who also found increased health benefits among lottery winners when compared to non-lottery winners. However, they also showed that lottery winners also drank and smoked more socially than non-lottery winners. Similar findings that lottery winners have better health indicators have also been reported by other researchers (such as Dr. Mikael Lindahl in a 2005 issue of the Journal of Human Resources).

On a more practical day-to-day level, most of the research on big winners has shown that their lives are much better as a result of their life changing wins but there are always a few winners who find other problems occur as a result of their instant wealth. They may give up their jobs and move to a more luxurious house in another area. This can lead to a loss of close friends from both the local neighbourhood and from their workplace. There can also be family tensions and arguments over the money and there is always the chance that winners will be bombarded with requests for money from every kind of cause or charity. There are also case reports in the literature of people become depressed after winning life-changing amounts of money (such as a 2002 study by Dr. S. Nissle and Dr. T. Bschor in the International Journal of Psychiatry in Clinical Practice), although these are presumably the exception as no researcher(s) would get case reports published showing people were happier after winning a large amount of money! However, despite potential problems, most of the psychological research (perhaps unsurprisingly) indicates that winners are glad they won.

Interestingly, one large study by Dr. Richard Arvey and his colleagues (published in a 2004 issue of the Journal of Psychology) of 1,163 lottery winners in the USA showed that the vast majority of lottery winners (63%) carried on working in the same job after their big win, with a further 11% carrying on working part-time in the same job after their big win. The mean average amount won by those who carried on working was 2.59 million US dollars. This appears to show that winning the lottery does not necessarily lead to a changing of lifestyle for the vast majority of winners although smaller scale studies have tended to show that the majority of lottery winners give up work following a big win of over $1 million US dollars.

There are also those groups of people who will view the acquisition of instant wealth as ‘undeserved’. Basically, when people win large amounts of money through gambling, other people around treat them differently even if the winners do not move neighbourhood or carry on in their job. This can lead to envy and resentment not just from people who know the winners but also from those in the locality of where the winners may move to. However, most gaming operators have an experienced team of people to help winners adjust to their new life and to minimize potential problems.

Research into the effects of high jackpots on human behaviour has been relatively sparse. The research that has been carried out suggests that huge jackpot winners do not suffer negatively as a result of winning. There is little research that indicates that high jackpot cause people to develop problems unless the large jackpot is combined with other structural features such as high event frequencies.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Apouey, B. & Clark, A.E. (2009). Winning Big but Feeling no Better? TheEffect of Lottery Prizes on Physical andMental Health. Fondazione Eni Enrico Mattei Working Papers (Paper 357). Berkeley Electronic Press.

Arvey, R.D., Harpaz, I. & Liao, H. (2004). Work centrality and post-award work behavior of lottery winners. Journal of Psychology, 138, 404-420.

Brickman, P., Coates, D. & Janoff-Bulman, R. (1978). Lottery winners and accident victims: Is happiness relative? Journal of Personality and Social Psychology, 36, 917-927.

Eckblad, G.F. & von der Lippe, A.L. (1994). Norwegian lottery winners: Cautious realists. Journal of Gambling Studies, 10, 305-322.

Gardner, J. & Oswald, A.J. (2001). Does money buy happiness? A longitudinal study using data on windfalls. Warwick University Mimeograph.

Gardner, J. & Oswald, A.J. (2007). Money and mental well-being: A longitudinal study of medium-sized lottery wins. Journal of Health Economics, 26, 49-60.

Griffiths, M.D. (2009). The lottery of life after a jackpot win. Western Mail, November 11, p.16.

Griffiths, M.D. (2010). The effect of winning large jackpots on human behaviour. Casino and Gaming International, 6(4), 77-80.

Griffiths, M.D. & Wood, R.T.A. (2001). The psychology of lottery gambling. International Gambling Studies, 1, 27-44.

Imbens, G. W., Rubin, D. B., & Sacerdote, B. I. (2001). Estimating the effect of unearnedincome on labor earnings, savings, and consumption: Evidence from a survey of lotteryplayers. American Economic Review, 91,778-794.

Kaplan, H. R. (1985). Lottery winners and work commitment: A behavioral test of theAmerican work ethic. Journal of the Institute for Socioeconomic Studies, 10,82-94

Kaplan, H.R. (1987). Lottery winners: The myth and reality. Journal of Gambling Studies, 3, 168-178.

Lindahl, M. (2005). Estimating the effect of income on health and mortality using lottery prizes as an exogenous source of variation in income. Journal of Human Resources, 40, 144-168.

Nissle, S. & Bschor, T. (2002). Winning the jackpot and depression: Money cannot buy happiness. International Journal of Psychiatry in Clinical Practice, 6, 181-186.

Parke, J. & Griffiths, M.D. (2007). The role of structural characteristics in gambling. In G. Smith, D. Hodgins & R. Williams (Eds.), Research and Measurement Issues in Gambling Studies. pp.211-243. New York: Elsevier.

Within you, without you: Where does addiction reside?

In 1984, Dr. Milton Burglass and Dr. Howard Shaffer published a paper in the journal Addictive Behaviors and claimed that arguably the important questions in the addiction field are ‘why do people become addicted to some things and not others?’ and ‘why some people become addicted and not others?’ Answers to these questions have been hindered by two common misconceptions about addiction, which to some extent have underpinned the ‘hard core’ disease concept of addiction. These are that addiction somehow resides within: (i) particular types of people or (ii) particular substances, and/or particular kinds of activity. That is, either some people are already ‘diseased,’ or else some substances/ activities cause this disease, or both.

There is a belief that some people are destined to become addicted. Typically this is explained in one (or both) of two ways. That some people (i.e., ‘addicts’) have an addictive personality, and that there is a genetic basis for addiction. The evidence for ‘addictive personality’ rests to a certain extent upon one’s faith in the validity of psychometric testing. Setting aside this major hurdle, the evidence in this area (as I argued with my colleagues Dr. Michael Larkin and Dr. Richard Wood in a 2006 issue of Addiction Research and Theory [ART]) is still inconclusive and contradictory.

First, psychologists have yet to determine which particular personality traits are linked to addiction. Studies have claimed that ‘the addictive personality’ may be characterized by a wide range of factors (e.g., sensation-seeking, novelty-seeking, extroversion, locus-of-control preferences, major traumatic life events, learned behaviours, etc.). The extent of this range stretches not only the notion of an ‘addictive personality’ but also the concept of ‘personality’ itself. Inevitably, much of this work relies on correlation analysis, and so the interpretation of results is not easily framed in terms of cause and effect. The approach is overly simplistic and is underpinned by a simple proposition that if we can divide people up into the right groups, then the explanation will emerge. However, addiction is far more complex than this. Of course, the relationship between individual bodies, minds, contexts, and life histories is complex and important – but it requires that we approach the matter from a more sophisticated and integrative position.

The search for a genetic basis for addiction rests upon the notion that some types of individuals are somehow ‘biologically wired’ to become addicts. In our 2006 ART paper, we argued that we must set aside any doubts about the limited conceptualization of ‘the environment’ that often typifies this kind of research, and its combination with epidemiological designs that are largely descriptive. Meta-analytic reviews have concluded that the heritability of addictive behaviour is likely to be controlled by many genes each contributing a small fraction of the overall risk. Furthermore, some of these same genes appear to be risk factors for other problems, some of them conceptually unrelated to addiction. We argued that the main point here is that while these findings do contribute something to our understanding of ‘why some people and not others,’ they do not adequately or independently explain the range of variation. Therefore the most we can say is that some people are more likely to develop problems under certain conditions, and that given the right conditions most people could probably develop an addiction. Emphasis needs to be placed on identifying those ‘conditions,’ rather than on searching for the narrowest of reductionist explanations.

We also argued in our 2006 ART paper that substances and activities cannot be described as intrinsically addictive in themselves (unless one chooses to define ‘addictive’ in terms of a substance or behaviour’s ability to produce tolerance and/or withdrawal, and to ignore the range of human experience that is excluded by this). Biologists may be able to tell us very valuable things about the psychopharmacological nature of the rewards that particular substances and behaviours provide, and the different kinds of neuroadaptation that they may or may not produce in order to effect tolerance and/or withdrawal. But we argue that this on its own, is not an adequate explanation for addiction. In 1975, Dr. Lee Robins’ classic study (in the Archives of General Psychiatry) of heroin-users returning from the Vietnam war is one example of the evidence that refutes this oversimplification. This study clearly highlighted the importance of context (i.e., that in a war zone environment individuals were addicted to heroin but on return to civilian life the addiction ceased to exist), and the framework provided by such contexts for making sense of addiction. In a hostile and threatening environment, opiates clearly provided something not usually required by most people; and given a cultural environment in which opiate use is a commonplace, and opiates are available, then opiate use ‘makes sense’. This study provides support for the assertion that some people are more likely to become addicted under some conditions, and that given the right conditions perhaps many people could understand what it means to be an addict.

So, with regard to the question, ‘why some individuals/addictions and not others?’ the rewards associated with various activities may be qualitatively very different, and may not necessarily be inherent or unique to a particular activity or substance, either. Many rewarding activities are rewarding because they present individuals with opportunities to ‘shift’ their own subjective experience of themselves (for example, see the research on Ecstasy use and bungee jumping that I published with Dr. Michael Larkin in a 2004 issue of the Journal of Community and Applied Social Psychology).

Frequently, a range of such opportunities is offered to the experienced user. Dr. Howard Shaffer (in a 1996 paper in the Journal of Gambling Studies) has pointed out that those activities that can be most relied upon to shift self-experience in a robust manner are likely to be the most popular – and (as a consequence) to be the most frequent basis of problems. So, obviously, our understanding of the available resources for mood modification must play a major part in understanding addiction. However, we must make a careful distinction between describing some substances as being more ‘robust shifters of experience’ than others (as we advocated in our 2006 ART paper) and describing some substances as ‘more addictive’ than others (which we argued against).

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Burglass, M.E. & Shaffer, H.J. (1984). Diagnosis in the addictions I: Conceptual problems. Addictive Behaviors, 3, 19-34.

Griffiths, M.D.  (2005). A ‘components’ model of addiction within a biopsychosocial framework. Journal of Substance Use, 10, 191-197.

Griffiths, M.D. (2011). Behavioural addiction: The case for a biopsychosocial approach. Transgressive Culture, 1(1), 7-28.

Griffiths, M.D. & Larkin, M. (2004). Conceptualizing addiction: The case for a ‘complex systems’ account. Addiction Research and Theory, 12, 99-102.

Larkin, M., Wood, R.T.A. & Griffiths, M.D. (2006). Towards addiction as relationship. Addiction Research and Theory, 14, 207-215.

Orford, J. (2001). Excessive Appetites: A Psychological View of the Addictions (Second Edition). Chichester: Wiley.

Robins, L.N, Helzer, J.E, & Davis, D.H (1975) Narcotic use in Southeast Asia and afterward. Archives of General Psychiatry, 32, 955-961.

Shaffer, H. J. (1996). Understanding the means and objects of addiction: Technology, the Internet, and gambling. Journal of Gambling Studies, 12, 461–469.

Tyndale, R.F. (2003). Genetics of alcohol use and tobacco use in humans. Annals of Medicine, 35(2), 94–121.

Walters, G. D. (2002). The heritability of alcohol use and dependence: A meta-analysis of behavior genetic research. American Journal of Drug and Alcohol Abuse, 28, 557–584.

A toning for reward and punishment: A brief look at the impact of colour on gambling behaviour

Researchers and those working in the gambling industry have been interested in the factors that lead to the acquisition, development and maintenance of gambling. Aside from individual differences, the combination of the situational characteristics of the environment, and the structural characteristics of the actual game being played have been highlighted as critical ingredients in determining these behaviours in relation to gambling. This idea parallels with that of store designers who manipulate various features of the environment in shops to encourage purchase behaviour in consumers.

Situational characteristics are typically those features of the environment that may encourage people to gamble in the first place, and in some cases to keep on gambling. Examples of such characteristics could include accessibility (e.g., the number of outlets or opportunities to gamble, membership rules); sensory factors (e.g., atmospherics, light, colour and sound effects); the use of advertising; access to other things (e.g., cash machines, alcohol, food); physical comfort (e.g., seating, temperature); and social facilitation (the presence or absence of other people in the vicinity). These are often acquisition factors and are often important in the initial decision for an individual to gamble. Structural characteristics are features of the game itself that can contribute to the development and maintenance of gambling behaviour. These can be reinforcing to the player as they offer constant rewards. For instance, the ‘aura’ of a slot machine may offer excitement, arousal and tension in terms of its high event frequency, near misses, stake size, and the use of music, lights and colour.

One characteristic that can impact on both a situational and structural level in gambling is colour. For instance, this can be manipulated and/or adapted in terms of the design of a slot machine or scratchcard, an Internet gambling website, or the décor and ambience of a gambling environment. Research more specifically into the psychology of colour has been somewhat controversial in how it affects individual emotions. The majority of literature in the colour psychology field has come from advertising and marketing papers. This is because they are interested in colour selection in the way that it may facilitate the sale of their products. It has been speculated that learning about consumers’ emotional reactions to colour can be a useful predictor of purchase behaviour. This is because certain colours can provoke a particular positive or negative reaction. For instance, red has consistently been found to be stronger, more exciting, and more arousing than blue. This concept has been applied in a variety of situations in an attempt to manipulate people’s behaviours. However, a lot of this evidence is anecdotal, as it is not based on any sort of controlled experimental design.

Colour preference has been explained in terms of cultural significance and associative learning. It has been suggested that associations of colour that have been developed in the past have been forwarded as explanations of perceptions of colour today. For example, blue has been associated with night, dark and quiet. Warm colours, such as red, are used in order to attempt to arouse consumers such as in gambling environments. Across cultures, red has predominantly been found to be the most effective in influencing human emotions. Individual responses to colour have also been explained in relation to the arousal that they produce. It has been suggested that colours that are on the extreme ends of the colour spectrum (e.g., red and violet) generate greater arousal than those in-between. However, when red and blue have been compared in terms of their influences on arousal, differences have been found between them, with red producing greater cortical arousal.

With regards to the gambling literature in this field there has been minimal research conducted looking at the impact of colour on gambling. In an observational  study I published with Helen Swift back in 1992, we reported our findings about various situational characteristics of five English amusement arcades. We noted that the interiors were generally red or towards the red end of the colour spectrum. This observation appears to suggest that gaming venue designers make use of the principle of red light exciting whilst gambling. Light and colour effects have developed in their sophistication over recent years and the gaming and casino industry have taken advantage of this when designing machines, games, and gaming venue interiors.

An old 1982 study by Graham Stark and colleagues in the journal Current Psychological Research provides one of the few empirical contributions assessing the effects of coloured light on gambling behaviour. Their study found that compared to gambling under blue light, gambling under red light leads to more risks taken, higher stakes made, and more frequent bets. They suggested that because blue is less arousing it leads to slower performance, as their attention is not specially focused on the task. As red was highly arousing it caused participants to focus on the salient aspects resulting in faster bets. The arousing effects of red were speculated to increase overt behaviour.

Similar types of research study have also been carried out on computer gaming. For instance, a study led by Dr. Sandy Wolfson in a 2000 issue of Interacting With Computers examined the effects of music and lighting on computer game play. It was found that red lighting led to participants underperforming in the latter games played (compared to blue), although initially both groups improved continuously. The red group’s heart rate also decreased in line with their decline in performance. This was explained in terms of red initially being more arousing, which led to higher concentration and less error rates than blue, but as time went on they became desensitized to its arousal.

A more recent experimental investigation by Jenny Spenwyn, Dr. Doug Barrett and myself in a 2010 issue of the International Journal of Mental Health and Addiction reported what we believe was the first ever empirical study into the combined effects of both music and lighting colour on gambling behaviour. While playing an online version of roulette, participants took part in one of four experimental conditions; (1) gambling with fast tempo music under normal (white) light, (2) gambling with fast tempo music under red light, (3) gambling with slow tempo music under normal (white) light, and (4) gambling with slow tempo music under red light. We reported a significant interaction between light and music for betting speed, and that the speed at which participants gambled was increased while playing under red light and fast tempo music.

It is clear that situational characteristics of gambling environments (including colour) appear to have the potential to play a role in the acquisition, development and maintenance of gambling behaviour. The success of the gambling establishment’s situational and structural characteristics (where success is defined as an increase in gambling due to the situational or structural characteristic) depends upon the psycho-situational and/or psychostructural interaction. The importance of a characteristic approach to gambling is the possibility of pinpointing more accurately where an individual’s psychological constitution is influencing gambling behaviour. Such an approach also allows for psychologically context specific explanations of gambling behaviour rather than explanations that focus solely on personality and individual differences.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Babin, B.J., Hardesty, D.M., & Suter, T.A. (2003). Colour and shopping intentions: The intervening effect of price fairness and perceived affect. Journal of Business Research, 56, 541-551.

Bellizi, J., Crowley, A.E., & Hasty, R.W. (1983). The effects of colour in store design. Journal of Retailing, 59, 21-45.

Bellizi, J. A. & Hite, R.E. (1992). Environmental colour, consumer feelings and purchase likelihood. Psychological Marketing, 9 (5), 347-363.

Friedman, B. (2000). Designing Casinos to Dominate the Competition. Reno, NV: Institute for the Study of Gambling and Commercial Gaming, University of Nevada.

Griffiths, M.D. (1993). Fruit machine gambling: The importance of structural characteristics. Journal of Gambling Studies, 9, 101-120.

Griffiths, M.D. & Parke, J. (2003). The environmental psychology of gambling. In G. Reith (Ed), Gambling: Who wins? Who looses? pp. 277-292. New York: Prometheus Books.

Griffiths, M.D. & Swift, G. (1992). The use of light and colour in gambling arcades: A pilot study. Society for the Study of Gambling Newsletter, 21, 16-22.

Grossman, R. P., & Wisenblit, J. Z. (1999). What we know about consumers colour choices. Journal of Marketing Practice: Applied Marketing Science, 5 (3), 78-88.

Parke, J. & Griffiths, M.D. (2006). The psychology of the fruit machine: The role of structural characteristics re-visited. International Journal of Mental Health and Addiction, 4, 151-179.

Parke, J. & Griffiths, M.D. (2007). The role of structural characteristics in gambling. In G. Smith, D. Hodgins & R. Williams (Eds.), Research and Measurement Issues in Gambling Studies. pp.211-243. New York: Elsevier.

Spenwyn, J., Barrett, D.K.R. & Griffiths, M.D. (2010). The role of lights and music in gambling behavior: An empirical pilot study. International Journal of Mental Health and Addiction, 8, 107-118.

Stark, G.M., Saunders, D.M, & Wookey, P.E. (1982). Differential effects of red and blue coloured lighting on gambling behaviour. Current Psychological Research, 2, 95-99.

Valdez, P. & Mehrabian, A. (1994). Effects of colour on emotion. Journal of Experimental Psychology, 123 (4), 394-409.

Wolfson, S., & Case, G. (2000). The effects of sound and colour on responses to a computer game. Interacting With Computers, 13, 183-192.

Yoto, A., Katsuura, T., Iwanaga, K. & Shimomura, Y. (2007). Effects of object colour stimuli on human brain activities in perception and attention referred to EEG alpha band response. Journal of Physiological Anthropology, 26, 373-379.

Way up the cost: Will the increased price of National Lottery tickets affect sales?

The following blog is based on a short article that I wrote for Nottingham Trent University’s Expert Opinion column published earlier this year (January 29, 2013) and is a written version of many of the comments I made in national and local  BBC radio interviews yesterday.

This week Camelot Plc increased  the price of a Lotto ticket from £1 to £2 – but will this 100% price increase have any effect on whether people play the bi-weekly game? My own view is that although there may be a dip in overall sales when the price of the tickets first increases, over time, sales are likely to return to pre-price increase levels.

The price of buying a lottery ticket is just one of many inter-connected structural characteristics that help determine whether potential players will play the lottery. Other structural characteristics in gambling activities include the size of the jackpot, the number of smaller prizes, the probability of winning the jackpot and / or smaller prizes, the speed of the game, how quickly players receive their winnings, the ease of playing the game, whether the game is chance-based or requires some skill, the number of chances to gamble on a single event, etc.

The chance of winning the bi-weekly lottery is an incredible one in 14 million. But is playing Lotto a tribute to public innumeracy and totally irrational? Not necessarily. Lotto offers a low-cost chance of winning a very large life-changing amount of money. Many psychologists would argue that playing Lotto is entirely rational behaviour given the small cost involved. Basically, it’s a small cost for millions of people buying hope. More importantly, we know that most players don’t think about the actual probability of winning but concentrate on the amount that could be won (i.e., the jackpot size). Players may also rationalize that the cost of a ticket is still cheaper than buying a pint of lager in a pub or a coffee atStarbucks.

Jackpot size is one of the most important factors in whether people play the lotto. The fact that the ticket price is doubling doesn’t take away the fact that there will still be an enormous jackpot. Additionally, to soften the blow of the increased price, the amount that can be won for matching three numbers will increase from £10 to £25. This again is likely to help sales maintenance. And if people do feel that £2 is too much for a single ticket, there are plenty of other games in the national lottery portfolio to choose from.

Another factor that is important in lottery profitability for the operators is that we tend to overestimate positive outcomes and underestimate negative ones. If someone is told they have a one in 14 million chance of being killed that day they would hardly give it a second thought because the chances are tiny. Given the same probability of winning Lotto people suddenly become over-optimistic (“It could be you!”).

The media also plays a part. By providing widespread coverage for the few huge winners, it helps us forget the millions of people who lost! Finally, for regular players who choose the same numbers every week, they become ‘entrapped’ fearing that the one week they don’t play will be the week their numbers will come up. Players who have picked the same numbers for years are still likely to play despite the price increase for the same reason.

The bottom line is that Camelot will have done lots of market research to determine whether players will be prepared to pay more money to play Lotto. Major decisions about pricing are key to future success and increased profits. If people stop playing Lotto in their masses, a return to a lower price will be inevitable. However, my guess is that most current Lotto players will continue to play a game as the thought of winning millions of pounds outweighs the price increase.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Arkes, H.R. & Blumer, C. (1985). The psychology of sunk cost.  Organizational Behavior and Human Decision Processes, 35, 124-140.

Griffiths, M.D. (1997). The National Lottery and instant scratchcards: A psychological perspective. The Psychologist: The Bulletin of the British Psychological Society, 10, 26-29.

Griffiths, M.D. (1997). Selling hope: The psychology of the National Lottery. Psychology Review, 4, 26-30..

Griffiths, M.D. (2008). Problem gambling and European lotteries. In M. Viren (Ed.), Gaming in New Market Environment. pp. 126-159. New York: Macmillan Palgrave.

Griffiths, M.D. (2010). The effect of winning large jackpots on human behaviour. Casino and Gaming International, 6(4), 77-80.

Griffiths, M.D. (2011). Gambling, luck and superstition: A brief psychological overview. Casino and Gaming International, 7(2), 75-80.

Griffiths, M.D. & Wood, R.T.A. (2001). The psychology of lottery gambling. International Gambling Studies, 1, 27-44.

Kahneman, D. & Tversky, A. (1973). Availability: A heuristic for judging frequency and probability. Cognitive Psychology, 5, 207-233.

Langer, E.J. (1975). The illusion of control. Journal of Personality and Social Psychology, 32, 311-328.

Langer, E.J. & Roth, J. (1975). The effect of sequence outcome in a chance task on the illusion of control. Journal of Personality and Social Psychology, 32, 951-955.

Tversky, A. & Kahneman, D. (1971). Belief in the law of small numbers. Psychological Bulletin, 76, 105-110.

Walker, M.B. (1992). The Psychology of Gambling. Pergamon, Oxford.

Wagenaar, W. (1988). Paradoxes of Gambling Behaviour. Erlbaum, London.

Wood, R.T.A. & Griffiths, M.D. (2004). Adolescent lottery and scratchcard players: Do their attitudes influence their gambling behaviour? Journal of Adolescence, 27, 467-475.