What makes people help each other? To explore the origin of human altruism, we tested whether 16-month-old infants have an expectation of helping behavior when they observe an interaction between others. Infants watched videos in which one (capable) agent had achieved a goal while the other (incapable) one could not. In a subsequent situation, the capable agent either helped the incapable agent achieve the goal (helping event), or ignored the incapable agent and achieved the goal alone (ignoring event). Infants looked longer at the ignoring event, suggesting that they expected helping behavior rather than ignoring behavior. The results are discussed in terms of infants understanding of the connection between goals and altruistic behaviors.