A Japanese study reveals that children under one year of age are attracted by images of heroism where the weak are protected against aggressors. In most societies today as in the past, protecting the weak out of pure altruism and for no personal gain is seen as an heroic act. Understanding these actions means recognizing the different forces at play, understanding that the hero’s actions will benefit the victim and not he aggressor and that the hero is acting intentionally. Understanding all this before knowing how to speak suggests that we have an innate sense of justice. It probably explains our enthusiasm both as children and adults for books, films and comics based on the actions of super-heroes. The study also shows that at the age of six months infants cannot discriminate between an intentional and unintentional act whereas by the age of ten months they can. A better understanding of the stages and development of our sense of justice could be useful in understanding social phenomena such as bullying.