The original use of the word "altruism" when coined by Durkheim implied that here was no reward and that the gains and losses to the individual were in pleasure or some other utility function rather than reproductive success and that the actor was aware of the gains and losses that might accrue.  However, very often a word is used differently in a specific field than in general usage (e.g., force in physics vs. forcing yourself to give up smoking). In inclusive fitness theory and related disciplines the gains and losses are to reproductive success and the actor and recipeint may or may not be conscious of those gains or losses.  Durkheim's definition is based on intent and the inclusive fitness definition is based on consequences.