When you define selfishness as you do, it becomes tautological and therefore meaningless. If individuals are atomic and autonomous agents making decisions that

When you define selfishness as you do, it becomes tautological and therefore meaningless. If individuals are atomic and autonomous agents making decisions that maximize whatever it is they value (survival, comfort, pride, ego) and minimizing whatever it is they dislike (pain, guilt, loneliness, cognitive dissonance), then everyone, including the "guy who lays down in front of the tank" that jessriedel mentions, is selfish by definition. [1] An alternate definition of selfishness: Consider the world as a set of concentric circles centered on an individual. The narrowest encompassing the individual, the next encompassing the people they love most (usually children), the next their greater circle of family or friends, and so on to the largest circle the includes the world. (What appears in any circle and how far from center it appears can vary greatly from person to person. Some include animals, the environment or god(s).) The more one's interests and decisions are concentrated on the inner circles, especially the most inner one, the more selfish one is. An altruistic person would be one where the gradient of interest doesn't peak at the center. This definition is in line with the meaning of "selfishness" as commonly used, its "common sense" definition. - [1] The only way your definition would not be tautological is if individual humans weren't atomic or autonomous agents. It's something to consider. It's certainly possible that we have genes that predispose us to care about or subconsciously act for the benefit of things beyond our individual self, in the same way individual cells in a multicellular organism are preprogrammed to act for the good of the organism. If multicellular organisms evolved from single-celled organisms and cells lost their "selfishness" in the process, it is entirely possible that it can happen to the "cells" that make up larger "organisms" such as a species or an ecosystem.