The relational discovery was investigated with classical Bongard problems. The arrangement of the instances was varied to facilitate the discovery of the correct or wrong relation in the first comparison. Irrelevant to-the-task arousal between the two comparisons of the categories enables the discovery of the relation when the first comparison generates the correct relation. When the wrong relation is highlighted first, arousal slows the overall encoding time. The results are consistent with the hypothesis that attention enhances dominant representation, and highlight the need to reconsider the facilitative role of attention in relational discovery as it is based on multiple comparisons.