What Does a Random Line Look Like: An Experimental Study

  • Nigel E. Turner
  • Eleanor Liu
  • Tony Toneatto


The study examined the perception of random lines by people with gambling problems compared to people without gambling problems. The sample consisted of 67 probable pathological gamblers and 46 people without gambling problems. Participants completed a number of questionnaires about their gambling and were then presented with a series of random and non-random lines. The participants rated lines as random if the pattern stayed near zero (the middle of the screen) and did not form anything that resembled waves. The probable pathological gamblers rated 2 of the patterns (jumps, and multi-wave) as significantly less random than non-problem gamblers. They also rated random lines significantly less random than the non-problem gamblers. That is, they seem to be able to find patterns both when they are really there and when they only appear to be there as in the case of random drift.


Problem gambling Random chance Erroneous beliefs 



We would like to thank Keith Stanovich, Roger Horbay, and Geoff Noonan for their help in designing and carrying out this study.

The research was supported by a grant from the National Centre for Responsible Gaming. In addition, support to CAMH for salary of scientists and infrastructure has been provided by the Ontario Ministry of Health and Long Term Care. The views expressed here do not necessarily reflect those of the Ministry of Health and Long Term Care or the National Centre for Responsible Gaming.


  1. Abbott, M. W., & Volberg, R. A. (1996). The New Zealand National survey of problem and pathological gambling. Journal of Gambling Studies, 12(2), 143–60.CrossRefGoogle Scholar
  2. Brysbaert, M. (1991). Algorithms for randomness in the behavioral sciences: a tutorial. Behavior Research Methods, Instruments, and Computers, 22, 45–60.CrossRefGoogle Scholar
  3. Kahneman, D., & Tversky, A. (1982). Judgement under uncertainty: heuristics and biases. In D. Kahneman, P. Slovic & A. Tversky (Eds.), Judgement under uncertainty (pp. 3–22). Cambridge: Cambridge University Press.Google Scholar
  4. Ladouceur, R., Gaboury, A., Bujold, A., Lachance, N., & Tremblay, S. (1991). Ecological validity of laboratory studies of videopoker gambling. Journal of Gambling Studies, 7, 109–116.CrossRefGoogle Scholar
  5. Langer, E. J. (1983). The psychology of control. Beverly Hills, CA: Sage.Google Scholar
  6. Lesieur, H. R., & Blume, S. B. (1987). The South Oaks Gambling Screen (SOGS): a new instrument for the identification of pathological gamblers. American Journal of Psychiatry, 144(9), 1184–8.PubMedGoogle Scholar
  7. Lesieur, H. R., & Blume, S. B. (1993). Revising the South Oaks Gambling Screen in different settings. Journal of Gambling Studies, 9, 213–33.CrossRefGoogle Scholar
  8. McCleary, R., & Hay, E. E. (1980). Applied time series analysis for the social sciences. Beverly Hills: Sage.Google Scholar
  9. Onghena, P. (1993). A theoretical and empirical comparison of mainframe, microcomputer, and pocket calculator pseudo random number generators. Behavior Research Methods & Instrumentation, 25, 384–395.CrossRefGoogle Scholar
  10. Toneatto, T., Blitz-miller, T., Calderwood, K., Dragonetti, R., & Tsanos, A. (1997). Cognitive distortions in heavy gambling. The Journal of Gambling Studies, 13, 253–266.CrossRefGoogle Scholar
  11. Turner, N. E. (1998). Doubling vs. constant bets as strategies for gambling. The Journal of Gambling Studies, 14, 413–429.CrossRefGoogle Scholar
  12. Turner, N. E. (2000). Randomness, does it matter? Electronic Journal of Gambling Issues. Issue 2. Available at
  13. Turner, N. E. & Liu, E. (1999). The naive human concept of random events. Paper presented at the 1999 conference of the American Psychological Association, Boston, Aug.Google Scholar
  14. Turner, N. E. & Horbay, R. (2003). Doubling revisited: the mathematical and psychological effect of betting strategy. Gambling Research, 15, 16–34.CrossRefGoogle Scholar
  15. Turner, N. E., Wiebe, J., Falkowski-Ham, A., Kelly, J., & Skinner, W. (2005). Public awareness of responsible gambling and gambling behaviours in Ontario. International Gambling Studies, 5(1), 95–112.CrossRefGoogle Scholar
  16. Turner, N., Littman-Sharp, N., & Zangeneh, M. (2006). The experience of gambling and its role in problem gambling. International Gambling Studies, 6, 237–266.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Nigel E. Turner
    • 1
    • 3
  • Eleanor Liu
    • 1
  • Tony Toneatto
    • 1
    • 2
  1. 1.Centre for Addiction and Mental HealthTorontoCanada
  2. 2.Public Health Sciences and PsychiatryUniversity of TorontoTorontoCanada
  3. 3.Department of Public Health SciencesUniversity of TorontoTorontoCanada

Personalised recommendations