We conduct a study of altruistic behavior among high school students using the dictator game. We find a much stronger norm of equal splitting than previously observed in the typical university student population, with almost 45 of high school subjects choosing an equal split of the endowment. Tests indicate that this difference is not due to factors traditionally considered in the analysis of these games, such as demographics. Rather, we find that dictators who score higher on a Social Generosity measure are much more likely to conform to the 50/50 norm. Additionally, high school students who score in the high range of an Independence measure send significantly less to recipients.