Necessary versus sufficient causal schemata for success and failure

197 subjects judged the perceived presence or absence of ability or effort, given information about task outcome (success or failure), the difficulty of the task (easy, intermediate, or difficult), and the state of the complementary cause (effort or ability). The data revealed that a multiple sufficient causal schema is used to explain common events. That is, the presence of ability or effort is perceived as enough to produce success at an easy task, while the absence of ability or effort is perceived as sufficient to result in failure at a difficult task. On the other hand, a multiple necessary schema tends to be employed to explain uncommon events. Success at a difficult task is believed to require both ability and effort, while failure at an easy task tends to be perceived as caused by low ability and low effort. In addition, there were disparities in the causal judgments for success and failure: failure outcomes are more likely to elicit a multiple sufficient schema. Further, in achievement-related contexts ability and effort are perceived as negatively covarying causal determinants of typical successes and failures. In addition to supporting hypotheses from attribution theory, the data shed further light upon the perceived determinants of success and failure, and demonstrate the influence of cognitive structures on achievement-related causal judgments.