Training people to think in opposites facilitates the falsification process in Wason’s rule discovery task

Opposition is implied in various types of reasoning processes, probably more than we imagine (for a review see Branchini et al. 2021; Byrne 2016, 2018). In the first part of the presentation, we will briefly revise evidence from studies testing the hypothesis that “thinking in opposites” might represent a simple and effective prompt to overcome fixedness in visuo-spatial insight problem solving (Bianchi et al., 2020; Branchini et al 2015). In the second part of the presentation we focus on two studies conducted with Italian adult participants which investigated the effects of this prompt on Wason’s rule discovery task (Branchini et al., 2023: Branchini et al., submitted). The results showed a significant improvement in performance under the prompt to think in opposites when compared to two control conditions, both in terms of the proportion of participants who discovered the correct rule and how quickly it was discovered. These findings are discussed in relation to previous literature showing improvements in performance that were prompted by strategies involving “contrast” as a critical factor.