Altruism is behavior that benefits others at some cost to the individual. As a philosophical concept, altruism was originally formulated by Auguste Comte as an ethical antithesis to egoism. In recent years social scientists and biologists have been especially interested in altruism, although the two groups approach the subject differently.
To most social scientists, altruism occurs when one individual consciously comes to the aid of another, without expecting anything in return. Several things are believed to influence this behavior: empathy, an emotional response that results from being aware of another's emotions; group norms, society's expectation of how people "should" behave toward others; social learning, the personal experiences one has with others; and immediate context, the actual situation at the time an altruistic act is called for (being in a good mood, considering oneself helpful and altruistic, being with others rather than being alone).
Social scientists emphasize the importance of social experiences in producing altruistic behavior. By contrast, biologists, especially sociobiologists, take a different position. They view altruism as any behavior that reduces the Darwinian fitness (reproductive success) of the altruist while increasing the fitness of another. Accordingly, the occurrence of altruism in nature is a biological puzzle, since genes whose effect is to make themselves more rare in future generations should soon disappear altogether. Many examples of animal altruism, however, are known: Worker bees, ants, and wasps are sterile but assist the queen to reproduce. It is common for animals to share food, help provide for another's young, defend others against predators, and give alarm calls when a predator appears.
All these acts enhance the fitness of others while often reducing that of the altruist (see sociobiology).
Sociobiologists have several explanations for the evolution of altruism. First, a behavior may only seem altruistic. It might actually contribute to one's reproductive success and thus be a selfish act after all. Second, apparent altruism could arise by natural selection if the giver eventually receives comparable benefits from the getter. This reciprocity is actually selfish behavior, although both parties ultimately benefit.
Two mechanisms for the evolution of behavior that actually reduce the personal fitness of the altruist are also recognized by sociobiologists: kin selection and group selection. Kin selection is actually genetic selfishness. Altruistic genes can prosper as long as they succeed in making enough copies of themselves in relatives who are fitter because of the altruistic act. The notion of group selection is that altruism could theoretically be selected if altruists benefited others within the group so that the group as a whole did better than other groups that lacked altruists. However, individual altruists would be at a disadvantage within each group. Therefore, group selection is considered less likely than kin selection as a mechanism for evolving altruism, although it is theoretically possible.