When reminded, or primed, of past winning outcomes as part of a controlled test, people were over 15% more likely to gamble and select the risky option. Surprisingly, being reminded of past losing outcomes did not change their gambling behaviour.
Led by the University of Warwick, the researchers demonstrated that the risky decisions people make are influenced by triggering them to remember the times they had previously won.
Dr Elliot Ludvig, from Warwick's Department of Psychology, explains:
"Our memories play a very significant role when making certain decisions. We are often risk averse when making decisions when a situation is new to us, but we rely on our memories when the decisions we make are based on past experiences."
The research, "Priming Memories of Past Wins Induces Risk Seeking," is published by the Journal of Experimental Psychology: General.
Discussing the results Dr Ludvig said:
"Subtle cues about winning outcomes are continuously apparent in casinos, from the whirring of slot machines to the millions of dollars of cash placed on the table for the final showdown in some poker tournaments. Our results confirm how these cues are apt to make people gamble more, by serving as reminders for those times that people have won money in the past."
The researchers tested their hypothesis by manipulating, or priming, the memory of participants for past outcomes in a simple risky-choice task.
The participants were repeatedly presented with the choice of selecting one of two doors as part of a computer test. The doors were selected from four coloured doors in the experiment. Three of the doors always led to guaranteed outcomes (0, 40, or 80 points), and the fourth, risky door led to a 50/50 chance of 20 or 60 points.
Each of these outcomes was always paired with a unique image of a fruit, similar to those used in slot machines. For example, the 60-point winning outcome might always be presented with cartoon grapes, whereas the 20-point losing outcome might always be presented with a cartoon watermelon.
In the task, people repeatedly chose between a safe option and a risky option that paid off with a larger or smaller reward with a 50/50 chance. Once in a while, that choice was "primed" or preceded by one of the fruit images, which served to remind them of a past winning or losing outcome.
The research was conducted in collaboration with Prof. Marcia Spetch of the University of Alberta, Canada, and Dr. Chris Madan of Boston College, USA.