Twenty-four fifth graders and 24 second graders participated in a.75:.25 probability learning task under three different punishment conditions—0, 1, and 3 units lost for any incorrect guess. The results indicated that these punishment amounts did not affect second-grade children’s overall response tendencies or strategies. The older children, however, made more A, responses when the amount of punishment was increased from the immediately preceding level. The results were further evidence that older children are more sensitive to the experimental contingencies set up in probability learning tasks.