[The pro-social nature of blood donation].

"L'établissement français du sang" faces chronic shortages of blood to meet the growing needs of the health system. This article aims at clarifying the pro social nature of blood donation. An analysis of the literature allows us to characterize the act as being altruist. The prospective of this focus is to test the labeling paradigm, which is to return to the experiment that makes a preparatory behaviour, information enabling someone to perceive themselves as generous versus stingy or helpful versus not helpful. Being true to nature as reasons and motivations that conduct to the act of giving blood, seems to be essential for fundamental and experimental approach.