Pragmatic influences on rule discovery in Wason's 2-4-6 task

The aim of the reported research was to investigate the determinants of poor performance on Wason's (1960) rule discovery task. Following the argument that the conversational pragmatics of the task cause reasoners to attach a presumption of relevance to the salient properties of the given 2-4-6 exemplar triple (Van der Henst, Rossi, & Schroyens, 2002), the first set of experiments set out to examine further the impact of perceived triple relevance on rule discovery. Although the results of these initial experiments did not rule out the possibility of a relevance effect, it was quickly established that the previous evidence used to support the relevance account was potentially confounded by other factors present within Van der Henst et al's experimental scenario. In establishing this conclusion, the question also arose as to whether participants can genuinely be assumed to be engaging in hypothesis testing when faced with Wason's 2-4-6 task instructions. It was subsequently proposed that the failure observed on the standard 2-4-6 task should not be attributed to a poor hypothesis testing strategy but rather to participants' misinterpretation of the task's intended objective. The final two experiments tested this idea by altering the task so as to emphasise the intended goal of discovering one of many possible rule alternatives. The subsequent results supported the proposed "misinterpreted objective account" of the standard 2-4-6 task in that clarifying the task's objective readily elicits genuine hypotheses testing behaviour, thereby promoting successful rule discovery. The thesis situates these findings within Evans' ( e.g., 2006) general hypothetical thinking framework and argues for a more positive view of people's hypothesis testing capacities than that which has previously stemmed from research employing Wason's rule discovery paradigm.EThOS - Electronic Theses Online ServiceGBUnited Kingdo