Perceived locus of causality is an important factor in assessing the impact of prior success or failure on later performance. In order to examine the effects of internal (self) versus external (partner) attributions on subsequent performance, two studies were conducted. In the first study 80 female undergradutes worked on a series of mazes with an ostensible co-subject who was actually a confederate. All subjects received success feedback and were led to attribute their success either to their own actions or to the actions of their partners. Half of the subjects were then tested on an additional maze, and the rest were tested on a different task. In the second study 92 female undergraduates followed the same procedures as those in the first study with minor variations. The results showed that subjects in the internal attribution condition performed better when tested on the same (maze) task than on a different task; the reverse was true for those in the external attribution condition. The findings indicate that attributions are important determinants of subsequent performance. (Author/BH)