ABSTRACT
In the standard form of Wason’s (1960) 2-4-6 task, participants must discover a rule that governs the production of sequences of three numbers. Studies typically show success rates of approximately 20%, which Wason attributed to a cognitive deficit that he labeled ‘confirmation bias’. In Tweney et al.’s (1980) formally equivalent Dual Goal (DG) form of the task, however, success rates are at least double to those seen on the standard task. If this facilitated performance could be accounted for, then this would go some way toward explaining the normally low performance on the standard problem. The present experiment examined two competing accounts of the DG superiority effect: Evans’ (1989) positivity bias explanation, and Wharton, Cheng and Wickens’ (1993) goal complementarity theory. The experiment independently manipulated the number of goals that participants had to explore (a single goal vs. two complementary goals) and the linguistic labels used to provide feedback (DAX and MED vs. ‘fits the rule’ and ‘does not fit the rule’). Results supported the goal complementarity account in that facilitation was evident in both DG conditions irrespective of the polarity of the feedback provided. We also discuss a novel finding: that it is the production of at least a single ‘negative’ triple that is most closely associated with task success.
