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1853, "unselfishness, opposite of egoism," from French altruisme, coined or popularized 1830 by French philosopher Auguste Comte (1798-1857), from autrui, from Old French altrui, "of or to others," from Latin alteri, dative of alter "other" (see alter). Apparently suggested to Comte by French legal phrase l'autrui, or in full, le bien, le droit d'autrui. The -l- is perhaps a reinsertion from the Latin word.
There is a fable that when the badger had been stung all over by bees, a bear consoled him by a rhapsodic account of how he himself had just breakfasted on their honey. The badger replied peevishly, "The stings are in my flesh, and the sweetness is on your muzzle." The bear, it is said, was surprised at the badger's want of altruism. ["George Eliot," "Theophrastus Such," 1879]
Instinctive cooperative behavior that is detrimental or without reproductive benefit to the individual but that contributes to the survival of the group to which the individual belongs. The willingness of a subordinate member of a wolf pack to forgo mating and help care for the dominant pair's pups is an example of altruistic behavior. While the individual may not reproduce, or may reproduce less often, its behavior helps ensure that a close relative does successfully reproduce, thus passing on a large share of the altruistic individual's genetic material.
A selfless concern for others.