Abstract

The ratio-bias (RB) phenomenon refers to the perceived likelihood of a low-probability event as greater when it is presented in the form of larger (e.g. 10-in-100) rather than smaller (e.g. 1-in-10) numbers. According to cognitive-experiential self-theory (CEST), the RB effect in a game of chance in a win condition, in which drawing a red jellybean is rewarded, can be accounted for by two facets of concrete thinking, the greater comprehension (at the intuitive-experiential level) of single numbers than of ratios, and of smaller than of larger numbers. In a lose condition, in which drawing a red jellybean is punished, the assumption of a third facet of concrete thinking, the ''affirmative-representation principle'', is necessary, as many participants reverse their focus of attention from the undesirable red to the desirable white jellybeans. Results supported the CEST explanation of the RB effect by demonstrating a predicted negative linear relation between the magnitude of the RB effect and the magnitude of the probability-ratios in the win condition and a positive linear relation in the lose condition. Support was also found for the associative principle of experiential processing.