Decision-making over time is an important aspect of adaptive social functioning. The main goal of this study was to investigate the development of this ability in young children. A simplified version of the Iowa Gambling Task was given to 69 children at 3 ages (3, 4, and 6 years). Children were also given an awareness test to assess their knowledge of the task. Significant age differences were found for awareness of the task while significant sex effects were found for performance on the task. Females chose significantly more from the advantageous decks than would be expected by chance in the second block. Males demonstrated no significant difference in choice of decks. Further analysis indicated female superiority in the task was not due to greater knowledge of the game. One interpretation of these results is that there are two systems affecting decision-making over time.